Saturday, 25 February 2017
Salman khan vs Tom Cruise
By Muhammad Sahanawaj
S.N Quantity. Unit. Symbol
1.Mass- Kilogram-kg
2.Length-metre- m
3.Time-second- s
4.Electric current-Ampere- A
5.Temprature-kelvin- K
6.Amount of substance-mole-mol
7.Luminous intensity-candela-cd
Thursday, 9 February 2017
Some important science question class10
By Muhammad SahanawajQ1:
Human eye and coluorful world basic questions for class 10 SA2
By Muhammad Sahanawaj
Fill in the blanks1.
The transparent spherical membrane coveringthe front of the eye is called ____________.
2. _______ is the surface which acts as screen and image is formed on it.
3. The coloured diaphragm between cornea and lens is known as __________.
4. A small hole in iris which controls the intensityof light entering the eye is called __________.
5. ____________ muscles hold the position of the lens and adjust its thickness.
6. The point on retina at which optic nerve leavesthe eye is called ___________. At this point if any image formed is not sent to the brain.
7. A point on retina which has highest concentration of sensitive cells and forms a clearimage when we see any object minutely, is called __________.
8. The ability of eye lens to focus near and far objects clearly on retina by adjusting is focal length is called the _______________ of the eye.
9. For a young human adult with normal vision, the near point is about ___________ and it is denoted by ______.
10. For a young human adult with normal vision, the far point is at __________.
11. To see objects with both eyes together is called _________ vision.
12. A transparent alkaline liquid between cornea and lens is called ___________. It helps in ________ of light rays in cornea.
13. A jelly fluid filling the space between lens and retina is called _________. It with stands atmospheric pressure and prevents eye ball fromcollapsing.
14. Human is made up of ___________ jelly fluid material and it is a _________ __________ lens.
15. In __________ distant objects are not clearly visible. It is corrected by using ________ lens.
16. In ___________ objects nearby are not distinctly visible. It is corrected by using _______ lens.
17. ________ occurs due to weakening of ciliary muscles in old age. It can be corrected by using __________ lenses.
18. Power of a spherical lens is the reciprocal value of its _______________.
Answers:1: cornea2: retina3: Iris4: pupil5: Cilliary6: Blind Spot7: Macula or yellow spot.8: accommodation9: 25 cm, D10: infinity (∞)11: binocular12: aqueous humour, refraction13: vitreous humour14: crystalline, double, convex15: myopia, concave16: hypermetropia, convex17: Presbyopia, bi-focal18: focal length
Science sample paper for SA2 Class10
Q1: What is coliform ?Answer: It is a group of bacteria found in human intestine.
Q2: List any four stakeholders which may help in the conservation of forests.Answer: People, the government, industrialists and Wildlife and nature enthusiasts.
Q3: What is reuse strategy ? Reuse strategy is considered better than the recycling strategy. Why ?
Answer: In reuse strategy, things are used again and again instead of throwing them. It is better than recycling of objects as no energy is used in this strategy for remaking of objects.
Q4: India has more than 50,000 strains of rice. Mention the level of biodiversity it represents.
Answer: It is a genetic variation within the species.
Q5: What do the three R’s refer to save the environment ? Which one of these would be the best for environment ?
Answer: Three R’s refers to Reduce, Recycle and Reuse.Reducing wastage of energy is the best for environment.
Q6: Why are coal and petroleum considered to benon-renewable sources of energy?
Answer: Coal and petroleum are considered non-renewable sources of energy because they are not being formed continuously in nature and are, therefore, not replenished. Continuous use will result in their depletion.
Q7: Which bacteria was found in Ganga water indicating contamination ?
Answer: Coliform bacteria found in Ganga water indicate contamination.Q8: Which one of the following gases is the majorconstituent of biogas: CO2, H2, CH4, CO2?Answer: CH4 (Methane)Q9: Suggest two ways to conserve forests.Answer: (i) By planting more trees.(ii) By banning cutting of trees.Q10: What are the water harvesting methods used in Maharashtra ?Answer: Bandharas and talsQ11: What harm has been caused to alpine meadows since nomadic shepherds have stopped from grazing their cattle in such meadows?Answer: The great Himalayan National Park formed had put this practice to an end. This resulted in tall grasses, preventing fresh growth of alpine grasslands in Himalayas.Q12: What would be the advantage of exploiting resources with short term aims?Answer: The exploitation of natural resources such as forest for obtaining forest products like timber which is used for making wooden houses, furniture and many other wooden things is the advantage of exploiting natural resources with short term aims.Q13: How did the Chipko Andolan ultimately benefit the local population ?Answer: Chipko Andolan forced the government to rethink their priorities. This experience has also taught people that destruction of forests canchange the quality of soil and the sources of water.Q14: What is meant by sustainable development?Answer: It is a development which can be maintained for a long time without undue damage to the environment.Q15: What measures would you take to conserve electricity in your house?Answer:1. Switch off fans and lights when not in use.2. Use of solar water heating system and solar heaters.3. Use of fluorescent tubes or CFL or LEDs.4. Use more natural light in rooms.Q16: Local people around forests are referred to as “stakeholders” for conservation of forests. Give reasons.Answer:(i) Locals are dependent on forest produce.(ii) Industries use tendu leaves in industries.(iii) Forest Department controls resources from forest.(iv) NGO’s working for conservator of nature and world life.Q17: Why are forests considered ‘biodiversity hot spots’ ?Answer: Forests are called biodiversity hot spots because it contains different species of plants, animals, bacteria, fungi, etc.Q18: State the meaning of biodiversity hot spotsAnswer: The richest and the most threatened reservoirs of plants and animals lives are termed as biodiversity hot spots.Q19: What important message is conveyed by Amrita Devi Bishnoi Award for wildlife conservation ?Answer: Messages of (i) afforestation and(ii) involvement of community in forest conservation is conveyed by Amrita Devi Bishnoi Award.Q20: What is water harvesting ?Answer: It means capturing of rain water where itfalls and taking measures to keep the water cleanby not allowing polluting activities to take place.Q21: What is the effect of continuous depletion of ground water along coastal region?Answer: It leads to movement of saline sea waterinto freshwater wells then spoiling their quality.Q22: For what purpose is the ‘Khadin’ technique used in Rajasthan ?Answer: Rain water harvestingQ23: Suggest a few measures for controlling carbon dioxide levels in the atmosphere.Answer:1. Reduce the consumption of petrol in the automobiles.2. Use CNG as cleaner fuel3. Plant more trees4. Do not burn litter and fields after harvesting.Q24: Write two points to be kept in mind while storing water in tanks.Answer: Storage tank should not be located close to the source of contamination and should be accessible for cleaningQ25: List any two causes for the failure of sustained availability of ground water.Answer: (i) Loss of vegetation cover.(ii) Pollution from industrial effluents.Q26: Write two advantages of water shed management.Answer: It increases biomass production.It prevents occurrence of drought and flood.Q27: Mention the estimated period upto which petroleum and coal reservoirs are expected to last.Answer: Petroleum : 40 years; Coal : 200 years.Q28: What are fossil fuels?Answer: The fuels like coal and petroleum that are formed from the degradation of biomass are called fossil fuels.Q29: Why is LPG considered a better fuel than coal ?Answer: Burning of coal leaves residues which are harmful and cause air pollution, whereas LPG does not produce smoke or ash.Q30: Name the two elements which are present both in CNG and petroleum.Answer: (i) Hydrogen, (ii) Nitrogen.Q31: Name any two poisonous products formed by burning of fossil fuels.Answer: Burning of fossil fuels produces CO2, water and oxides of nitrogen and sulphur. It causes acid rain.Q32: Name the four basic elements which formed coal from biomass.Answer: Carbon, hydrogen, nitrogen and oxygen.Q33: Which canal has brought greenery to considerable areas of Rajasthan?Answer: Indira Gandhi Canal.Q34: Who started Chipko movement?Answer: Sunder Lal Bahuguna
Sunday, 5 February 2017
English reader textbook question class10SA2
By Muhammad Sahanawaj
CBSE _NCERT Class X Unit 1, THE TRIBUTE Textbook Exercise QuestionsCBSE - Class X, Literature Reader for English (Communicative)Unit 1,THE TRIBUTETextbook Exercise QuestionsQ.3: The narrator of the story is a man called Babuli.
Answer these questions briefly:
(a) Why did Babuli have to visit his family village?
Ans:(a) There was a quarrel between Babuli’s two sisters-in-law. His elder brother had written a letter, asking him to come home, because all movable and unmovable ancestral property was to be divided up among Babuli and his two brothers. Because of this Babuli had to visit his village as his presence on this occasion was indispensable.
(b) Why had he not been to his village for a long time?
(b) Babuli had not been to his village for a long time because he was too busy with his life and work in the city.
(c) When Babuli told his wife that the family land had to be divided, how did she react?
ans(c) When Babuli told his wife that the family land had to be divided she was totally unperturbed. She just asked him “When?” as if she was all prepared and waiting for this event to take place. Then she became greedy as she wanted Babuli tosell the land and hand over the entire money to her.
(d) When Babuli arrived at the family home, what changes did he notice? What was thereason for these changes?
ans.(d) When Babuli arrived at the family home, he was not welcomed as he used to be. In the entire house there was an unusual quietness. It was as if the entire house was preparing for a collapse.The reason for these changes was the demand for partition by the second brother and his wife. This resulted into the quarrels between the two sisters-in-law of Babuli and disagreements withinthe family.
(e) Who wanted to buy Babuli’s share of family lands?
ans.(e) Babuli’s second brother wanted to buy his share of the family lands.
(f) What did Babuli do with his share?
ans(f) Babuli gave his share to his elder brother.
Q.4: Do the following extracts contain a metaphoror a simile?
For each, explain its meaning
.(a) A lot of cobwebs have settled around me. (paragraph 2)
(b) I listened to all this like an innocent lamb looking into the darkness.
(10)(c) The past was sprouting up in me. The childhood days and the days now! Time has coagulated for me.
(20)(d) We moved from boundary to boundary. Everywhere I could feel the imprints of his feet, his palm and his fingers. On the bosom of the paddy fields sparkled the pearls of my elder brotTHER 🅢🅦🅔🅐🅣..
🅰🅽🆂🆆🅴🆁🆂
Ans:(a) This extract contains a metaphor. The comparison is between cobwebs and Babuli’s neglect of his family. It is just like the neglected portion of a house which gets covered by dust and cobwebs, Babuli’s ties with his family had become covered with the dust and cobwebs of neglect. His preoccupation with his life in the city caused him to overlook his mother, his elder brother, and his past.
(b) This extract contains a simile. The sadness and the fear at the impending division of his home and ancestral properties as well as his wife’s plan to use the money gained from this division made Babuli feel as if he were a helpless lamb about to be killed and torn into pieces by thebutcher.
(c) This extract contains two metaphors. Babuli compares his memories to sprouting seeds. The memories of his life in his village rise up within him just like seedlings that rise up from the ground during germination. He feels that time hasbecome standstill. The overall change shows twocontrasting views of time: ‘time’ that is in motion and ‘time’ that has become standstill.
(d) This extract contains two metaphors. Babuli compares the paddy fields with a human figure. The fields are adorned by the results of his elder brother’s hard work. He compares the sweat drops of his elder brother with pearls. The implication is that the sweat drops are as precious as pearls. The overall image is that of a human figure wearing a necklace.
Q.6: (a) Babuli’s elder brother used to say to his wife:“You must make the dish as delicious as possible, using mustard paste for Babuli.”What are Babuli’s feelings for his brother, as he remembers these words?
(b)“I shivered with the cold, and my own ingratitude,” says Babuli.Quote two instances from the story which shows his ingratitude.
(c)“Brother …you are my land from where I could harvest everything in life,” says Babuli.What are land and harvest compared to by Babuli? What does he wish to convey to his elder brother, through these words?
🅐🅝🅢🅦🅔🅡 🅚🅔🅨
Ans:(a) Babuli feels love, gratitude and affection.
(b) The instances that shows Babuli’s ingratitude are -
(i) When Babuli got down from the bus, he forgot to touch his elder brother’s feet.(ii) For the last two years in Bhubaneswar, Babuli never thought of home nor even tried to know the well-being of his family by writing a letter.
(iii) After he started a comfortable income, it never occurred to him that he should buy some winter clothes for his elder brother.
(c) Babuli means that his elder brother’s love is the “land” from which he has “harvested” his success. Babuli wishes to say how grateful he is to his elder brother.
Q.8: Write an additional paragraph at the end of the story, starting:When at last I reached home, my wife was waitingfor me. Her hand was outstretched, and her eyes were gleaming with anticipation.Ans: When at last I reached home, my wife was waiting for me. Her hand was outstretched, and her eyes were gleaming with anticipation. On seeing her, once the feeling of satisfaction which had been there in my heart since I left the village, vanished. For the first time I questioned my decision. But then the memories of my childhood,elder brother’s image, his toiling in the fields, the sacrifices which the elder brother and his wife made for me etc. came to my mind and I felt I haddone what was right.After I went inside, sitting on the sofa I narrated the proceedings of the partition to my wife. When she heard of the second brother’s offer, she said, “So, what did you do?” I said her, “I did not sell myshare. I have given it to my elder brother as a small tribute.”She was silent for a minute and I could see a hint of irritation in her eyes too. But very soon she could reconcile with me as she told, “Ok, you havedone the right thing. The fridge and the scooter etc. can be purchased later also.” Saying this she went into the kitchen.Sample Questions on this Chapter[The Tribute]
Q.1: Give two incidents from the lesson ‘The Tribute’ to show that Babuli regretted being ungrateful to his brother.
Q.2:“I shivered with cold, and my own ingratitude”says Babuli. Quote two instances from the story which reveals his ingratitude.
Q.3:“He stopped for a moment near the pile of things and unfastened the strap of his wrist-watch and placed it on the heap with the other things.”(a) Why did the elder brother do so? How did he feel?
(b) Mention any four traits of the elder brother that you get to know from the sto🅱🅰🅱🆄🅻Q.5: What impression do you get about the elder brother after rADINg the story ‘The Tribute’?
Q.6:“I can’t understand how a stranger could all of a sudden become so intimate, only sharing a little warmth by giving a silent promise of keepingclose.”Who is Babuli referring to here and why so?
Q.7: Imagine you are Babuli’s elder brother. The partition has taken place and you received Babuli’s note that reads:Brother,What shall I do with the lands? You are my land from where I could harvest everything in life. I need nothing save you. Accept this please. If you deny, I shall never show my face to you again.Babuli.Overwhelmed with emotions answer here as you write a letter to Babuli.
Basic CBSE question of carbon and its compound class10SA2
By Muhammad Sahanawaj
MCQ’S Based on : Aldehydes, Ketones and HaloalkanesQ01. The general molecular formula of aldehydesand ketones is1) CnH2n-1.O2) CnH2nO3) CnH2n+2O4) CnH2n+4OQ02. Aldehyde functional group can occur1) Any where in the carbon chain2) In the middle of the carbon chain3) Only at the second carbon atom4) only at either end carbon atom of the chainQ03. Propan-2-ol on treatment with copper at 3000c forms1) Acetone2) Acetaldehyde3) Ethane4) Both 1 and 2Q04. Which of the following is correct?1) Aldehydes undergo Cannizzaro’s reaction2) Aldehydes are less susceptible to oxidation than ketones3) Aldehydes are more susceptible to oxidation than ketones4) Formaldehyde forms CuO with Fehling’s solutionQ05. IUPAC name of CH3CHOHCH2CHO is1) 2-hydroxybutanal2) 2-hydroxypropanal3) 3-hydroxybutanal4) b-hydroxybutanalQ06. The reagent which can be used to distinguish acetophenone from benzophenone is1) 2, 4-dinitrophenyl hydrazine2) Benedict’s solution3) Tollen’s reagent4) I2 and Na2CO3Q07. Toluene on reacting with chromyl chloride gives:1) Chlorotoluene2) Benzyl chloride3) Benzaldehyde4) Benzoic acidQ08. Mesitylene is prepared from1) CH3CHO and conc. HNO32) CH3COCH3 and conc. H2SO43) CH3COCH3 and conc. HCl4) CH3CHO and conc. H2SO4Q09. (CH3)2C = CHCOCH3 can be oxidised to (CH3)2C = CHCOOH by1) Chromic acid2) NaOI3) Cu at 3000c4) KMNO4Q10. Oppenaur oxidation is the reverse process of1) Wolff –Kishner reduction2) Rosenmund’s reduction3) Clemmensen reduction4) Meerwein-Pondorf-Verely reductionQ11. In the reaction CH3CHO + CH2(COOH)2 ----------pyridine/heat ------->A. The compound A is1) CH3COOH2) C2H5COOH3) CH3CH = CHCOOH4) COOHCH = CHCOOHQ12. Benzaldehyde reacts with alcoholic KCN to give:1) C6H5CH(OH)CN2) C6H5CH(OH)COC6H53) C6H5CH(OH)COOH4) C6H5CH(OH)CH(OH)C6H5Q13. Aldehydes and ketones do not react with1) sodium bisulphite2) phenyl hydrazine3) semi carbazide4) di hydrazine sodium phosphateQ14. Which of the following will undergo aldol condensation?1) CH2=CHCHO2) CH=CCHO3) C6H5CHO4) CH3CH2CHOQ15. Which type of isomerism is shown by the pentanone1) Chain isomerism2) Position isomerism3) Functional isomerism4) All 1, 2 and 3Q16. Paraldehyde is formed as a result of polymerisation of1) CH3CHO2) HCHO3) CH3OH4) CH3CH2CHOQ17. Aromatic aldehydes in the presence of CN-ion give acyloins. The reaction is known as1) Perkin reaction2) Benzoin condensation3) Claisen condensation4) Cannizzaro’s reactionQ18. Which of the following method is used to convert ketone into hydrocarbon1) aldol condensation2) Reimer Tieman reaction3) Cannizzaro’s reaction4) Clemmensen’s reductionQ19. Which will not give formaldehyde on heatingor upon distillation?1) Formalin2) Trioxane3) Paraldehyde 4) ParaformaldehydeQ20. When ethanal is heated with Fehling’s solution it gives a precipitate of1) Cu2) CuO3) Cu2O4) CuO+Cu2O+CuQ21. When CH3CHBrCH2CH3 is reacted with alcoholic KOH the major product is1) CH3CH=CHCH32) CH2=CHCH2CH33) CH3CH(OH)CH2CH34) CH3CH2CH2CH3Q22. Benzene reacts with n-propyl chloride in the presence of anhydrous AlCl3 to give1) 3-propyl-1-chlorobenzene2) n-propyl benzene3) No action4) Isopropyl benzeneQ23. Identify Z in the following series:CH2=CH2 -----HBr---> X ------Hydrolysis ----> Y -----I2/ excess NaOH ----> Z1) C2H5I2) C2H5OH3) CHI34) CH3CHOQ24. Bromoethane reacts with silver nitrite to form1) Nitroethane2) Ethane3) Ethylnitrite4) Nitroethane and ethylnitriteQ25. Which of the following compounds on oxidation gives benzoic acid?1)o-Chlorophenol2)p-Chlorotoluene3) Chlorobenzene4) Benzyl chlorideQ26. Reaction between alkyl halide and sodium metal is called1) Wurtz reaction2) Kolbe’s reaction3) Clemmensen’s reaction4) Wurtz - Fittig’s reactionQ27. Which compound gives iodoform by reaction between I2 and NaOH?1) CH3OH2) C2H5OH3) C3H7OH4) C2H5OC2H5Q28. The reactivity order of halides in dehydrohalogenation reaction is:1) R-F > R-Cl > R-Br > R-I2) R-I > R-Br > R-Cl > R-F3) R-I >R-Cl > R-Br > R-F4) R-F > R-I > R-Br > R-ClQ29. Which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism?1) ethyl chloride2) isopropyl chloride3) chlorobenzene4) benzyl chlorideQ30. SN2mechanism proceeds through intervention of:1) carbocation2) transition state3) free radical4) carbanionANSWERSQ 01 2Q 11 3Q 21 1Q 02 4Q 12 2Q 22 4Q03 1Q 13 4Q 23 3Q 04 3Q 14 4Q 24 4Q 05 3Q 15 4Q 25 4Q 06 4Q 16 1Q 26 1Q 07 3Q 17 2Q 27 2Q 08 2Q 18 4Q 28 2Q 09 2Q 19 3Q 29 4Q 10 4Q 20 3Q 30 2
Classification of element class 10 CBSE best notes SA2
By Muhammad Sahanawaj
1. Periodic table: The table which classifies all the known elements on the basis of their properties in such a way that elements with similar properties are grouped together.The first classification of elements was as metals and non-metals.In 1789, Lavoisier first attempted to classify the elements into two divisions namely Metals and Non-metalsThis served only limited purpose mainly because of two reasons:(i). All the elements were grouped in to these two classes only. The group containing metals was very big.(ii) Some elements showed properties of both-metals and non-metals and they could not be placed in any of the two classes.2. All earlier attempts on the classification of the elements were based on their atomic weights.3. The first attempt towards the classification of elements was made by Johann Dobereiner, a German chemist in 1829. He made sets of three elements which showed similar chemical properties and he called it triads.as their oxide are alkalies in nature and exist in the Earth12. No Place were given for forth coming elements by Newland.13. . Newland placed unlike elements in same slot like Co andNi placed with F , Cl and Iodine14. When Nobel gases were discovered in 1900 law of octave fail and 9th element became similar to 1st. in Newland Octave4. The Triad was approximately the mean of the atomic weights of the other two members and the properties of the middle element were in between those of the other two members.5.The average of the atomic masses of Li and K =1/2(7+39)= 23 (Na)5. The major drawback of Dobereiner classification was that the concept of triads could be applied to limited number of elements. It was also possible to group quite dissimilar elements into triads.6.Lithium, Sodium, Potassium are called Alkalies metal as they react with water and form alkalies (Causticsolution)7.Calcium, Strontium, Bromine are called Alkalies Earth metalas they react with water and form saltand exist in the Earth.8. Chlorine, Bromine, Iodine are called Halogen as they are reactive non-metallic elements which form strongly acidic compounds with hydrogen from which simple salts can be made.9.In 1864 John Alexander Newland, an English chemist noticed that “when elements are arranged in the increasing order of their atomic masses. He found that "every eighth element had properties similar to the first element.”10. Newland called this as the Law of Octaves due to its similarity with musical notes .11. Newland could arrange elements in this manner only up to calcium (atomic mass 40 ) out of a total of over sixty elements known at his time.15. Doberenier‘s triads also exist in the column of Newland octaves like Li, Na, K.16.In1869 Mendeleev a Russian chemist while trying to classify elements discovered that on arranging in theincreasing order of atomic mass, elements with similar chemical properties occurred periodically.17. A periodic function is the one which repeats itself after a certain interval.18. According to the periodic law : The chemical and physicalproperties of elements are a periodic functionof their atomic masses.19. Mendeleev believed that atomic mass of elements was the most fundamental property. A tabular arrangement of theelements based on the periodic law is called periodic table.20. The Seven horizontal rows present in the periodic table are called periods.21. Properties of elements in a particular period increase or decrease from left to right.22. The nine vertical columns present in it are called groups and are numbered from I to VIII and Zero (Roman numerals).23. Mendeleev’s periodic table had some blank spaces for undiscovered elements24. Scandium, gallium and germanium, discovered later, haveproperties similar to Eka – boron, Eka–aluminium and Eka–silicon, respectively.25. The Mendellev's periodic table helped in correcting the atomic masses of some elements based on their positions in the table.26. Atomic mass of beryllium was corrected from 13.5 to 9. With the help of this table, atomic masses of indium, gold, platinum etc., were corrected.]27. Mendeleev fail to givefixed position to hydrogen in the Periodic Table.It was placed in group IA and group VI B.28. Hydrogen resembled both the alkali metals and the halogens. So, it was placed above both the groups and could not be given a fixed position in Mendeleev’s Periodic Table.29. There is no place given for isotopes in Mendeleev’s Periodic Table30. Different isotopes of same elements have different atomic masses; therefore, each one of them should be given a different position in the periodic table. On the other hand, because they are chemically similar, they had to be given same position.31. There are anomalous pairs of elements in Mendeleev’s Periodic Table : At certain places, an element of higher atomic mass has been placed before an element of lower atomic mass. For example, Argon (39.91) is placed before potassium (39.1)32. Disimilar elements placed together: Noble metals like Cu, Ag and Au are placed along with chemically dissimilar alkali metals in Group I . Similarly, Mn possessing very few similarities with halogens have been placed in VII group.33. Similar elements separated: In Mendeleev's periodic table, certain chemically similar elements such as copper andmercury; gold and platinum have been placed in different groups.34. Anomalous pairs : In the Mendeleev's Table based on atomic weight, the positions of certain pairs , e.g. Argon( at. wt = 39.94) and potassium ( at. wt = 39.1) : Cobalt( at wt=58.93 ) and nickel ( at wt = 58.71 ) ; Tellurium at wt = 127.60)and iodine (atomic weight = 126.90 ) would be reversed. In other words, certain pairs of elements are misfit in the periodic table, if atomic weight is the basis of classification.35. The formulae for the oxides of the following elements: K, C, AI, Si, Ba. according to Mendeléev’s Periodic Table are: K(potassium) belongs to group I. Thus, formula of its oxide is K2O, similarlyCO2, Al2O3,SiO2,, BaO.36. The criteria used by Mendeleev in creating his periodic table are:(1) The chemical and physical properties of an element is theperiodic function of its atomic mass.(ii) The elements were arranged in a period such that their properties changed from metallic to non-metallic.(iii) The elements were arranged in groups, such that all the elements have same, but graded physical and chemical properties.37. The noble gases are placed in a separate group because (a) Noble gases are chemically inactive and hence constitute a separate group.(b)2. Noble gases as a group offer a perfectdividing line for starting a new period in the periodic table.38. Moseley showed that the atomic number of an element isa more fundamental property. The ModernPeriodic Law can be stated as : ‘Properties of elements are a periodic function of their atomic number.’39. The Modern Periodic Table has 18 vertical columns known as ‘groups’ and 7 horizontal rows known as ‘periods’.40. The elements present in anyone grouphave the same number of valence electrons. The number of electrons in the valence shell determines the group of the element. If the element has 1 or 2 electrons, then it belongs to group 1 or 2, respectively. If the element has 3 to 8 electrons, then its group is equal to 10 + number of valence electrons.41. Elements with the same number of occupiedshellsare placed in the same period.For example, if an element has 4 electron shells, it belongs to the 4th period.42. The atomic size depends on the distance between the centre of the nucleus and the outermost shell of an isolated atom.43. The atomic radius decreases inmoving from left to right along a period. This is due to an increase in nuclear charge (increase in no. of proton without increasing shell) which tends to pull the electrons closer to the nucleus andreduces the size of the atom.44. Theatomic size increases down the group. This is because new shells are being added as we go down the group. This increases the distance between the outermost electrons and the nucleus so that the atomic size increases inspite of the increase in nuclear charge.45. The valencies of all elements of the same group are the same. The valence of an element with respect to oxygen is equal to its group number.46. The melting points and boiling points decrease while moving down in group of metals.47. The melting points and boiling points increases while moving down in group of non-metals.48.Metallic character of the element decreases along a period because the effective nuclear charge acting onthe valence shell electrons increases due to decrease in atomic size.49.Metallic character of the element Increases while moving down in group becausethe effective nuclear charge experienced by valence electrons is decreasing as the outermost electrons are farther away from the nucleus(due to increase in atomic size).50. Metals tend to lose electrons while forming bonds. That is why they are electropositive in nature.51. Non-metals are electronegative as they tend to form bonds by gaining electrons.52. The tendency to gain electrons increases in a period due to decrease in atomic size.53. The tendency to lose electrons increases in a group due to increase in atomic size54. Non metallic character decreases down in group becauseof decrease in tendency to gain electron which is due to increase in atomic size.55. Non metallic character increases left to right in group because of increase in tendency to gain electron which is dueto decrease in atomic size.Periodic propertiesLeft to right in periodDown a groupAtomic sizeDecreasingIncreasingTendency to lose ElectronDecreasingIncreasingTendency to gain ElectronIncreasingDecreasingMetallic CharacterDecreasingIncreasingNon - metallic CharacterIncreasingDecreasingDistance b/w Valance Electron and NucleusDecreasingIncreasingForce of attraction b/w Valance Electron and NucleusIncreasingDecreasing56. Alkali Metals: Lithium, sodium, potassium, rubidium, caesium and francium have one electron in the valence shell. They are called alkali metals because their hydroxides are strong alkalis.57. Halogens: The elements placed in group 7 (VIIA) and have seven electrons in their valence shell and so are mononvalent.All these elements form salts called halides, e.g. NaCl, NaI, KCl, KI etc. Halogen is an ancient Greek word meaning 'salt producer.58. Transition Elements: Elements belonging to 3 to 12 groups are called transition elements. They are called transition elements because they are placed between the most reactive metals on the left and non-metals on the right.59. Inner-transition Elements:The 6th period consists of elements that have atomic numbers 58 to 71. They are called Lanthanides.The 7th period consists of elements that have atomic numbers 90 to105. They are called Actinides. Both of them are called inner transition elements.60. The group VIA elements are calledchalcogensbecause most ores of copper (Greek chalkos) are oxides or sulfides, and such ores contain traces of selenium and tellurium.
History notes of all SA2 chapters CBSE
By Muhammad Sahanawaj
(History) Chapter _The Rise of Nationalism in EuropeQ.
1 Define Nation:Ans: A ‘Nation’ has thus been defined as “a body of people who feel themselves to be actually linked together by certain affinities which are so strong and real from them that they can live happily together, are dissatisfied when disunited and cannot tolerate subjection of peoples who do not share theseideas.”
Q.2 What do you mean by nationalism?Ans: The words ‘nation’ and ‘nationality’ are derived from the Latin word ‘Natus’ which means a ‘race’. Devotion, love, and patriotic feelings for one’s own nation is called ‘Nationalism’.
It is a feeling of politicalconsciousness and unity among the people of a state.
Q.3 What is the main contribution of the French Revolution to the world?
Ans: The French Revolution led to the transfer of sovereignty from the monarchy to a body of citizens. It proclaimed that it was the people who would henceforth constitute the nation and shape its destiny.
Q.4 What factors led to the rise of Nationalism in Europe?
Ans: Factors that led to the rise of Nationalism in Europe. Nationalism provided one of the greatest forces in Europe in the 19th century. The following were responsible for the rise of nationalism in Europe:1) Decline of Feudalism:Feudal lords were a great tumbling bloc in the way of the rise of the nationalfeelings among the people. But many causes led to their fall. Many of them died in mutual warfare. The crusades also impoverished the barons. Without the destruction of nobility the cause of nationalism might have been greatly suffered.2) Weakness of Papacy and the Holy Roman Empire. In the Middle Ages the Church enjoyed and exaltedposition and commanded a great power. But the Renaissance and Reformation movements led to awakening among the people and weakened the authority of the Pope. Consequently, national churches and national states were established in many countries.3) Wars. Sometimes the wars also infused the spirit of nationalism. The Hundred Years War between England and France gave rise to national feeling both in France and England. It roused nationalism among the people of both the countries in the face of a common foe.4) Foreign Rule. In certain countries foreign rule played an important part in the growth of nationalism. The foreign rulers suppressed the people under them cruelly and mercilessly. But all this led to reaction and united the people against the foreign rule and infused the spirit of nationalism in them to free themselves from the foreign yoke.5) Geographical Factor. Geographical factor also helped a lotin the rise of nationalism. National boundaries of a country surely create the feeling of political consciousness and oneness among the people. For example, England is boundedby sea on all the sides. It facilitated the rise of the feelings of unity and nationalism among the English.6) Reaction against Injustice. Reaction against injustice also leads to nationalism. The Vienna Settlement after the Napoleonic Wars tried to suppress the force of revolution and nationalism in Europe. But soon there started a reaction against the arbitrary rule and the people of the subjected countries started national movements for their independence.7) Contribution of Great Writers. Many writers, poets, statesmen, politicians and philosophers, etc. alsomade valuable contribution to the growth of nationalism. Machiavelli had bben rightly called the father ofmodern nationalism. The writings of J. S. Mill, Fitech, Mazzini,Garibaldi etc. went a long way in rousigpolitical consciousness and national spirit among the people.
Q.5 Mention the obstacles in the way of the Italian unification.Ans. There were many obstacles in the way of the unification of Italy in the 19th century. Some of the most important are the following:1. Division of Italy into so many States.Italy, which was once the leader of Renaissance, became a very weak and powerless country in the 16th century. So sItaly lost its unity and was parceled out into so many states.These states always used to quarrel among themselves and thus they rendered themselves quite weak.2. Foreign Rule.Foreign invaders took advantage of Italy’s weakness and invaded it over and over again. Especially France and Austria established their rule over a great part of Italy. Napoleon, the French Emperor, had conquered the whole of Italy. Thus the foreign rule was great hurdle in the way of the Italian unification.3. Congress of Vienna.After the downfall of Napolean, the Congress of Vienna once again divided Italy into small states. Lombardy nd Venetia were handed over to Austria while Parma, Tuscany and Modena were handed over to France. Similarly, many old rulers, who were against the spirit of unity, were restored to their respective thrones. Thus the Congress played a great havoc with the task of Italian unification.4. The Pope of Rome.The Pope of Rome was keeping Rome and its adjoining territories under his dominance. He was acting as the head ofall the Christian countries of the world as such he was also proving a great hurdle in the way of the Italian unification. He had kept the foreign forces to throw out any attempt of the patriots to snatch Rome from him.5. Reactionary Rulers. Even those states which were under the dominance of Italian rulers were not at all cooperative with the nationalists. They were reactionaries and were ever ready in curbing the nationalist feelings. These rulers were, thus, also proving a great hurdle in the way of Italian unification.The Nationalist Movement In Indo-ChinaQ.1 Why did the French develop infrastructure in Vietnam?Ans: i) To help transport goods for trade.ii) To move military garrisons.iii) To control the entire region.iv) French business interests wee also pressing the government of Vietnam to develop the infrastructure further.Q.2 What was the cause of the defeat of the French forces in the battle of Dien Bien Phu?Ans: i) The valley where the French garrisons were located was flooded in the monsoon which made it impossible for theFrench forces and thanks to move.ii) The whole area was covered with bushes and jungles making it difficult for the French air force to trace the anti-aircraft guns hidden in the bushes and the jungles.Nationalism In IndiaQ.1 What did the slogan of Swaraj mean? How was the slogan of complete independence different fromit? When and where was the slogan of complete independence adopted?Ans: The slogan of Swaraj meant self-government or the system of government that was prevailing in the elfgovernedBritish colonies. The slogan of Swaraj, however, did not meancomplete independence from allforeign control. Thus, Swaraj and complete independence differed much from each other. Swaraj was self-government but not free from foreign control while complete independence meant freedom from all internal and external control.Q.2 What is the importance of 26th January 1930?Ans: 26 January, 1930. In 1929 at the Lahore Session of the Indian National Congress, under the presidentship of JawaharLal Nehru, the Congress declared the attainment of completeindependence as its chief goal. It was also decided to celebrate 26 January as the Independence Day all over the country. As such on 26th January, 1930, the Independence Day was celebrated all over the country and the Congress flag was hoisted at many places.Q.3 Name the factors that made the national movement a mass movement at the end of the First WorldWar.Ans: The following were main factors that made the national movement a mass movement at the end of the First-World War:1) The arrival of Mohandas Karamchand Gandehi on the political field of India gave an impetus to the national movement and converted it into a mass movement. His method of non-violent resistance, introduction of the spinningwheel and the gospel of the Hindu-Muslim unity drew millionsof people intothe National Movement.2) The war expenditure imposed on India had impoverished the masses so much that they turned against the British Government in large members.3) The Montague-Chelmsford Reforms (1919) fell short of the aspirations of the Indians. They furtherangered the Indian masses.4) The defeat and dismemberment of Turkey by the Alies hadturned the Muslim masses against the BritishGovernment.5) The Rowlatt Act and the Jallianwala Bagh Tragedy had aroused a wave of popular indignation throughoutthe country.Q.4 When was the Muslim League formed? Describe briefly the policies of the Muslim League from1906 to 1940. When was the formation of a separate state ofPakistan adopted as the main aim ofthe Muslim League?Ans: The Muslimi League was formed on 30th December, 1906. Aga Khan, Nawab Salimullah of Dacca and MohammadAli Jinnah were some of its prominent leaders.1) to ask for more and more reforms for the Muslims.2) to protect and advance the political rights and interests of the Muslims of India.3) to promote amongst the Muslims of India, the feelings of loyalty to the British Government for gettingmore and more benefits for the Muslims.4) to keep the Muslim masses away from the Congress.5) to make a demand for the separate electorate and then fora separate state for the Muslims.It was with these objectives in mind that the Muslim League at its Lahore Session in 1940 A.D. for the first time asked for the formation of a separate state of Pakistan.Q.5 Why was the Simon Commission boycotted by the Indians? Give two reasons.Ans: Simon Commission. In November 1927, the British Government appointed the Simon Commission to look into the working of the Act of 1919 or Montague-Chelmsford Reforms and to suggest changes, if necessary. This commission was headed by a London Barrister named Sir John Simon so it is generallyknown as the Simon Commission. This Commission comprising of seven members, arrived in India in1928 A.D. but everywhere it was boycotted by the Indian people.Why was it boycotted by the Indian People?Now a question arises as to why the Simon Commission was boycotted by the Indian people. The reasons for this are not too far to seek:1) Firstly, this Commission did not include any Indian memberin it.2) Secondly, the clauses of this Commission did not contain any hope of ‘Swaraj’ for the Indians.Q.6 What were the reasons for launching Civil Disobedience Movement by the Congress?Ans: In the Lahore Session (Dec. 1929) of the Congress, it was decided to launch the Civil DisobedienceMovement. There were many reasons for launching this movement.1) The British Government has deprived the Indian people of their freedom so it was a crime to submit sucha rule.2) The Congress has declared Complete Independence as its aim in the Lahore Session of 1929 so the mosteffective way of gaining such a freedom was through non-violence by starting the civil disobediencemovement including nonpayment to taxes.3) The British Government has economically exploited the people.4) Not only economically it has exploited the masses politically, culturally and spiritually.The Making of A Global WorldQ.1 What is Rinderpest?Ans: It was a fast spreading disease of cattle plague which had a terrifying impact on people’s livelihood andthe local economy of many countries and especially Africa in the 1890s.Q.2 What was called Hosay?Ans: The Trinidad, a south American country, the riotous Muharram procession or carnival began to be called ‘Hosay’.Q.3 Name some Indian Entrepreneurs who ventured abroad?Ans: (i) Shikaripuri Shroffs and Natthukottan Chetiarrs who financed export agriculture in Central and SouthEast Asia.(ii) Hyderabadi, Sindhi traders who set up their establishments at busy parts world wide.Q.4 Which countries were known as ‘Alies’ in the first World War (1914-1918)?Ans: Britain, France, Russia and U.S. were known as Allies.Q.5. How much was the human loss in the First World War?Ans: About nine million people dead and 20 million injuredQ.6. Who was Henry Ford?Ans: He was well-known pioneer of mass production in the field of car manufacturing.Q.7. What were the Axis Powers in the Second World War?Ans: Mainly Nazi Germany, Japan and Italy.Q.8. What was the human loss in the Second World War?Ans: At least 60 million people are believed to have been killed in this war, directly or indirectly or indirectly,and millions more were injured.Q.9. What is the international monetary system?Ans: It is the system which links national currency with the monetary system. This system was fixed on fixedexchange rates.Q.10. What do you mean by G-77?Ans: It was a Group of 77 developing countries which did not benefit from the fast growth which the Western economies experienced in 1950s.Q.11. What is Globalisation?Ans: Globalisation means integrating our economy with the world economy. As a result, producers of othercountries can sell their goods and services in India and likewise India can also sell its goods and services in other countries. As a result of globalization, the different countries of the world become economically inter-dependant on each other.Q.12. What led to globalization?Ans: (i) Trade(ii) Migration of the people in search of work.(iii) The movement of capitalQ.13. Why did the indentured hired on Contract workers from India become ready to migrate to othercountries?Ans: (i) Cottage industries declined and they got deep in depth.(ii) Land rents rose and they failed to pay them.(iii) Their lands were forcibly cleared for mines and plantations.Q.14. Whed why was the indentured labour migration abolished?Ans: It was abolished in 1921 because India’s nationalist leaders opposed this system as abusive and cruel.Q.15. What were the major items of exports from India between 1812 and 1870?Ans: (i) Raw cotton whose export rose from 5% to 35% between 1812 to 1871.(ii) Opium shipment to China which enabled the British to finance its tea and other export from China.Q.16. What is meant by the Assembly line?Ans: When different parts of a machine like cars and manufactured at different places but are assembled at one single place, such a system is called an assembly line.Q.16 What was the main aim of post-war international economic system?Ans: (i) To preserve economic stability(ii) Full employment in the industrial world.Q.17. Why were the Multi-National Companies (MNCs) attracted towards the developing countries?Ans: (i) Because wages were relatively low in such countries.(ii) It was thought better to invest in these countries for more and more of profits.Q.18. Write short note on – The decision of MNCs to relocateproduction to Asian countries.Ans. MNCs are multinational companies which invest money in different countries. From the late 1970s, they began to shift production operations to low wage Asian countries. Such a thing or decision had a far reaching impact.i) Such a decision increased the job opportunities in the Asiancountries and to a great extent they helped insolving the unemployment problem.ii) These MNCs helped the Asian countries to come out of theformer colonial powers which still held themain controls of economic power in many new independent countries, but which were once under their control.iii) The coming of MNCs in Asian countries enabled the people to enjoy new varieties of things which theybegan to manufacture in bulk in these Asian countries.iv) These multinational companies by their relocation of industry to low-wage countries of Asia stimulated world tradeand capital flow.v) They proved a great help to the true beginning of globalisation.Q.19. What is meant by the Bretton Woods Agreement?Ans: The Bretton Woods Agreement was signed between the world powers in July 1944 as a result of theUnited Nations Monetary and Financial Conference held at Bretton Woods in New Hampshire, U.S.A. This conference established the International Monetary Fund (IMF) and the World Bank to preserve economic stability and full employment in the industrial world.Both these institutions commenced financial operations in 1947 which they are continuing upto this date. Under this system or agreement, the national currencies followed the fixed exchange rates and were pegged to the US dollars. Thissystem ushered an era of unprecedented growth of trade andincomes for the Western industrial nations and Japan. There was also worldwide spread of technology.Q.20. What do you mean by the Silk Routs. What was their importance?Ans: Of all the routes connecting the ancient world, the most important routes were the silk routes. They areknown to have existed even before the Christian era and thrived almost till the fifteenth century. Theseroutes proved a good example of vibrant pre-modern trade and cultural links between different parts of theworld.These ancient routes were called the silk routes because along these routes were mainly carried the silkcargoes from China to different regions of Asia, Europe and Northern Africa. But by the same routes werecarried the Chinese pottery, the Indian spices and textiles. In turn, through these silk routes were carriedprecious metals – gold and silver, from Europe to Asia. Among these routes, the Buddhist preachers, Christian missionaries and later on the Muslim preachers travelled far and wide. Thus these silk routes proved a great source of trade and cultural exchanges.Q.21. What causes led to the decline of the Indian textiles?Ans: Upto the 18th century, the Indian textiles had a wider market all over the world but in the 19th century, it saw a rapid decline from 30% around 1800 to 15% by 1815. By the 1870s, this proportion had dropped to below 3%. What a tragedy !The chief causes for this rapid decline were the following:i) The first was the Industrial Revolution in England as a resultof which England stopped all imports oftextiles from India.ii) Instead it flooded the Indian market with machine-made cloth which was cheaper and more attractive.iii) While heavy taxes were imposed on the export of Indian textiles, the British textiles and their imports into India were left duty free.iv) The East Indian Company bought almost all the cotton from the Indian bazaars and sent to England tofeed the cotton factories there. Almost no or very little cottonas a raw material was left for the Indian textile industries.v) Heavy taxes were imposed on the Indian manufacturing units engaged in textiles so they were made to diea natural death.vi) Even the railways were used to export cotton from India and carry British cloth to the Indian market.Thus the British Government choked the Indian textile industry by their unjust and indiscriminateeconomic policies.Q.22. Explain the causes of Great Depression.Ans: There was a world-wide economic crisis in 1929 which in many countries continued upto 1934. It started in the U.S.A. but soon it engulfed many countries of the world except Russian. Some of its causes were the following.i) The First World War (1914-1918) had given a great boost tothe American industry. But after the warwhen its industries continued producing different articles at the breakneck speed, there was a glut in the market. The exports had fallen and the home market could not absorb all those products. As a result the unsold stock of goods began to pile up in the 1930s. the lack of buyers ruined both the industrialists andthe farming community. Thus USA was caught in a severe economic crisis.ii) As a result the American capitalist stopped all loans to the European countries thus halting all productionthere.iii) The sudden stoppage of American capital caused an unprecedented economic crisis there.iv) The defeat of Germany in the First World War had already ruined her and her industry. So she becameand easy victim of the economic crisis.v) Last but not the least, the labour saving machines and the abundances of agricultural products was alsoresponsible for the economic depression in Europe.Q.23. What were the results of the Economic Crisis of 1929-1934?Ans. The Economic Crisis of 1929-1934 had far reaching effects on U.S.A., Europe and other part of the world.i) The economic depression led to the deterioration of the economic conditions of the capitalist countries ofEurope and the U.S.A.ii) There was a great fall in the industrial production as the demand fro goods of all types also fell, men werelaid off and factories closed. The industrial production in 1933 was only half the 1929 level.iii) Unemployment soared very high and world unemploymentdoubled. There were 5 to 10 crores of unemployed persons inthe world. The number of unemployed persons stood round 14 million in theU.S.A. alone.iv) There was a great fall in the living standard of the people in all parts of the world.v) The economic depression resulted in poverty. Many peoplebecame poor and led a miserable life andbegan to die of hunger.vi) Agricultural prices fell disastrously in many countries.vii) The results of this depression in Italy and Germany were insecurity, unemployment, poverty, frustration,panic and discontentment. This led to the rise of Fascism in Italy and Nazism in Germany. Democratic Party cam to powerin U.S.A. under the leadership of Roosevelt. It adopted the policy of ‘New Deal’ to overcome the evil effects of the economic depression and to provide jobs to the people and to improve thecondition of the workers.viii) The New Deal of Roosevelt in America and the economic nationalism of Britain necessitated statecontrol.The Age of IndustrialisationQ.1 What was the result of the import of Manchester cloth to India?Ans: i) It ruined the cloth industry in India because the Manchester cloth was both cheap showy and durable.ii) The weavers were forced to give up their ancestral profession of cloth weaving and had to work aslabourers in urban areas.Q.2. What was the result of First World War on Indian industries?Ans: The First World War gave a great boost to the Indian industries because of the following reasons:i) The British mills became busy with the production of war materials so all its export to India virtually stopped.ii) Suddenly, Indian mills got clearance to produce different articles for the home market.iii) The Indian factories were called upon to supply various war related materials like jute bags, cloth foruniforms, tents and leather boots for the forces and so on.Q.3. Explain the meaning of term ‘Industrial Revolution’.Ans: The term ‘Industrial Revolution’ stands for those developments and inventions which revolutionized thetechnique and organization of production in the latter half of the 18th century. The Industrial Revolution in face replaced the domestic system, by the new ‘factory system’. In place of animal and manual power, new machines and steam-power were used for producing things. This revolution replaced the cottage industry by the factories, the handwork by the machine-work and the craftsmen and the artists by the capitalist and the factory-owners.Q.4. Why does industrialization affect farming or agriculture?Ans: Effects of Industrialization on Agriculture. With Industrialization grew the demand for raw-materials so rapidly that it forced the cultivators to adopt new methods to ensure more production. New machines were invented for digging the soil, sowing seeds, reaping the harvest and thrashing the corn. New crops were sown and chemical fertilizers were developed for a bumper harvest. Means of irrigation were improved and new breeds of farm cattle were developed. These and several other techniques ensured more food for the growing population and more raw material for the growing industries.Q.5. What conditions are favourable for the continuing growth of industries in India?Ans:1) India abounds in coal and iron-ore deposits, which are essential for the development of industries. We canexport our surplus coal and iron-ore to other countries.2) We have a number of perennial rivers whose perpetual flow of water can be used to generate more electric power.3) We can produce abundant raw-materials as wer have vast agricultural potential in rich and fertile land ofour big country.4) We have a vast network of roads and railways and our shipping industry has also developed considerablyand as such we can transport our goods not only within India but also outside India.5) India itself is a big market with its big population. Besides, Indian goods are in great demand in severalArabian and Asian countries.6) We have good potential in capital as well. Besides, the foreign aid and the foreign investment can alsohelp us in this respect.Q.6. Explain the factors responsible for the Industrial Revolution in England.OrGive reasons why Industrial Revolution started first of all in England.OrExplain those factors which were responsible for the Industrial Revolution in England.Ans: The Industrial Revolution began in England in the later half of the 18th century as favourable conditionsfor such a development were present there:1) Men like Walpole, who was a great economist, encouragedthe foreign trade which brought more andmore wealth to England. The British traders had thus accumulated sufficient capital that was needed toestablish new factories.2) England had plenty of natural resources like iron and coal which are essential for industries.3) England had established many new colonies from where they could easily get cheat raw-materials andwhich could also serve as best markets for finished goods.4) England had developed a large shipping industry which solved their problem of transporting things todistant lands.Q.7. ‘Industrialisation gave birth to Imperialism’. How?OrHow did Industrial Revolution give rise to Capitalism? Elucidate.Ans: There is no exaggeration in calling imperialism as the ill-begotten child of industrialization. Other thingsbeside, industrialization chiefly needs two things. One of them being the constant supply of raw-materialsand the other is that the finished goods be sold at the same speed. The industrialized countries had introduced heavy import duties as protective tariffs to check the import from other countries. Faced withthe problem of finding new markets for their products, the producer nations chose such countries where industrialization had not yet reached. Hence a race for bringing those areas under their effective occupation or effective influence started among the various industrialized nations. As a consequence, Britain, France, Germany and Japan, etc. set up their colonies in Asia, Africa and South America etc.These colonies served their two purposes of being the suppliers of cheap raw materials and an easy market for theirfinished goods. In this way, it can be rightly said that industrialization gave birth to imperialism or carving out of new colonies in other lands.Urbanization and Urban LifeQ.1 Give some chief characteristics of the city.OrDistinguish between cities on the one hand and town and villages on the other.Ans: Chief Characteristics of the Cities and their Distinction from the Towns and Villages:i) Cities, like London and Bombay, were larger on scale as compare to towns and villages like Ur, Nippurand Mohejodaro.ii) Cities could develop only when there was an increase in food supplies that could support a wide range ofnon-food producers. Villages and towns required only food supplies in small quantitites.iii) Cities were often the centre of multifarious activities, like trade and industry, religious institutions,intellectual pursuits and administrative set-up while villages and towns had restricted activities.iv) In cities, a large number of social groups such as merchants, traders, bankers, wholesale traders andbrokers, skilled artisans and various professionals lived while the villages and towns were predominatedby farmers and petty artisans and shopkeepers.Q.2. What were the changes in the kind of work available to women in London between the 19th and the20th century? Explain the factors which led to this change.Ans:1) Women in the later 18th and early 19th centuries were employed in large number in the factories becausethey were available at cheaper rates than men.2) In the 19th century due to technological developments, women gradually lost their industrial jobs andforced to work elsewhere. Some of them began to work as maid servants so much so that their numberrose to quarter of a million as recorded by the Census of 1861.Some other women, who remained within the four walls of their houses, increase the family incomethrough various activities as tailoring, washing, making matchboxes etc.However, there was a change once again in the beginning of the 20th century when women gotemployment in the wartime industries and offices linked with war activities. They happily gave up theirdomestic services.Q.3. Why a number of Bombay films were about the lives of the migrants?Ans: There is no denying the fact that a number of Bombay films were about the lives of the migrants. Therewere reasons for the same.1) Most of the film directors, film producers, playwriter, dramatists and artists were themselves migrants,who came from far off areas to Bombay, so naturally they were familiar and more interested in themesrelating to them. The Kapoors, the Ghais, the Chopras, the Sehgals (Shri K.L. Sehgal, the immortalsinger) were all migrants (from Punjab), without whose help were cannot think of the Bombay dreamworld.2) The migrants, especially the labourers and factory workers,led a very pathetic life which can easily beconverted into a good theme for films. So many films were made on the housing problems of the migrants. The clash of interests between the tenants and owners of the ‘Chawls’ over and over again werewoven into interesting themes by the different Directors and Film Producers.Q.4. Explain what is meant by the Haussmanization of Paris. To what extent would you support oroppose this form of development? Write a letter to the editor of a newspaper to either support oroppose this, giving reasons for your view.Ans: What is meant by Haussmanization of Paris. It simply means the new city of Paris as was designed bythe chief architect of new Paris. At the instance of Napoleon III (a nephew of Napoleon Bonaparte), Haussmann built the new city of Paris for continuous 17 years (between 1852 to 1869). He designed straight, broad avenues (or boulavards) and open spaces and transplanted full grown trees. By 1870, aboutone-fifth of the streets of Paris were the creation of Haussmann. In addition night patrols were introduced,bus shelters were built and tap water introduced.Opposition of Haussmanization. Many opposed this form of development. About 350,000 people wereevicted from the centre of Paris. Some said that the city of Paris had been monstrously transformed. Somelamented the passing of an earlier way of life and the development of an upper class culture. Othersbelieved that Haussmann had killed the street and its life to produce and empty boring city.Arguments in Support of Haussmanization. The new Paris city soon got converted into a civic pride asthe new capital became the toast of all Europe. Paris becamethe hub of many new architecture, social andintellectual developments that were very influenced through the 20th century in many parts of the world.Guidelines. The students now to write a letter to the editor of a newspaper to either support or opposethis, giving reasons for their views.Print Culture and The Modern WorldQ.1 Who was Martin Luther?Ans: He was a great religious reformer of Germany, who by his criticism of the Roman Catholic Church laidthe foundation of the Reformation Movement in Europe.Q.2. What is meant by Reformation?Ans: It was a reform movement started in the 16th century to reform the Catholic Religion.Q.3. When did the first printing press come to India?Ans: The printing-press first came to India in Goa with the Portuguese missionaries in the mid-sixteenthcentury.Q.4. What led to the diversification in the use of print in China?Ans: Upto the sixteenth century, the print was used only by the scholars officials but in the 17th century, themerchants along with the reading public also began to use print in their everyday life.Q.5. What was the use of printing press?Ans: (1) It enabled people to produce books at greater speed.(2) The production of books in large number created a new culture of reading and enlarged the number ofreaders.Q.6. Write a short note on – The Gutenburg Press.Ans: Before the invention of the Printing Press, it was very difficult to spread knowledge because the bookswere written by hand and they were also very costly. Knowledge was the privilege of the wealthy people only, but the things changed with the invention of the printing press. The first printing press was set up inGermany by Gutenburg in 1448. He developed metal types for each of the 26 characters of the Romanalphabet and devised a way of moving them around so as to compose different words of the text. Hisnovel press came to be known as the moveable type printing machine and it remained the basic printtechnology for the next 300 years. His press could print 250 sheets on one side per hour.The first book he printed was theBible.Q.7. Who was Martin Luther? What is his contribution to the Protestant Reformation?OrGive reason for the following – Martin Luther was in favour ofprint and spoke out in praise of it.Ans: Martin Luther was a great reformer of Germany. The credit for starting Reformation in Germany goes to him. In 1512 A.D., he went to Rome for pilgrimage. He was stunned to see that the Pope had sunk to thelevel of an Italian Prince and led a very luxurious life. The corrupt practices of the church and immorallife of the clergymen brought a great change in his ideas and he became a staunch opponent of the Pope.When working as a Professor at the University of Wittenburg, he was asked to sell ‘Indulgences’ as ameans of salvation he frankly refused. Instead he wrote downhis objections against the scale ofIndulgences’ in Latin, in the form o f95 statements known as ‘Ninety-Five Theses’ and nailed them on thedoor of the church at Wittenburg and challenged the scholarsto have a debate on them. In these Theses,Luther laid great stress on faith and strongly opposed the sale and purchase of Indulgences as a means ofsalvation. He believed in the infallibility of the Bible and not ofthe Pope.Luther’s Theses were printed and distributed widely in Germany. They created a great excitementeverywhere. Consequently, a National Church was established in Germany and prayers began to be heldin the German language. This fact proved the beginning of the Reformation Movement in Europe.Luther’s translation of the New Testament were sold 5,000 copies within a few weeks and the secondedition appeared within three months. Deeply grateful to printhe remarked, “Printing is the ultimatelygift of God and the greatest one”.Q.8. write a short note on ‘Erasmus’s idea of the printed books’.OrWho was Erasmus? Why is he remembered in history?Ans: Erasmus (1466 – 1533). He was a great reformer of Holland. He was the pioneer of Reformation inHolland. He was the foremost advocate of the new learning and was deadly opposed to corrupt andimmoral life of the pope and the clergymen. He severely condemned evil practices and abuses of thechurch. He was in favour of bringing reforms in the church by peaceful means, but he disliked violentmethods, ‘Pocket Dagger’, ‘Praise of Folly’ and ‘New Testament’ are his famous works. In the ‘Praise ofFolly’ he had denounced the abuses of the church in a very sarcastic manner. He wanted to effect thereforms in the church by a direct appeal to the reason of man. It has been rightly remarked. “The jokes ofErasmus did the Pope more harm than the anger of Luther”. His influence extended to England, France,Germany and Italy also.Erasmus’s words about printing are worth quoting, He says, “To what corner of the world do theynot fly, these swarms of new books? It may be that one here and there contributes something worthknowing, but the very multitude of them is hurtful to scholarship, because it creates a glut, and even ingood things satiety is most harmful…….. (printers) fill the world with books, not just trifling things (suchas I write, perhaps), but stupid, ignorant, slanderous, scandalous, raving, irreligious and seditious books,and the number of them is such that even the valuable publications lose their value”.Q.9. Why did some people in eighteenth century Europe think that print culture would bringenlightenment and end despotism?OrWhat is the contribution of print to the spread of knowledge?Ans: Contribution of Print – There is no denying the fact that the invention of print has greatly contributed tothe spread of knowledge. Without this invention, all the progress that we see today was not possible. Thewords of the German reformer Martin Luther in favour of print, and worth quoting. Deeply grateful toprint, he said, ‘Printing is the ultimate gift of God and the greatest one.” What better words can be said infavour of print!Author after author, whether educationist, religious and socialand the political giants, sing in favour ofprint:i) Without the introduction and invention of the new print technology, the quicker and cheaperreproduction of texts was not possible.ii) Printing reduced the cost of books as a result books could reach out to wider sections of thesociety otherwise they would have been only the luxury of the elite or the rich people.iii) As a result of the printing technology, the time and labour required to produce each book camedown which resulted in flooding the market, reaching over to ever growing readership.iv) Painting led to the rise of literacy rate in almost all countries of the world in the 17th and 18th andthe subsequent centuries.v) Similarly, the ideas of scientists and philosophers became more accessible to the common people.The writings of great thinkers like Thomas Paine, Rousseau, Montesquien, Voltaire completelyrevolutionized the moods of the people and some of them began to think that print culture wouldbring not only enlightenment but also end of despotism.Most of the revolutions of the world, which ended despotism and brought about democrate governmentsin the world were much because of the advancement of the print culture. Without the spread of educationand knowledge, how could such a transformation be possible.Q.10. Explain how print culture assisted the growth of nationalism in India.Ans: How Print Culture assisted the Growth of nationalism in India? There is no doubt that the print culture,both Indian press and the liberature, also played a vital part in the growth of nationalism in India. In thenineteenth century, a large quantity of national literature was created which brought about a greatrevolution in the minds of the people and inspired them to fight against British imperialism. The Indianpress also contributed in arousing the national consciousness among the people of India. Newspapers likethe ‘Indian Mirror’. ‘Bombay Samachar.’ ‘The Amrit Bazar Patrika’ ‘The Hindu’. ‘The Kesari’, andseveral others had a great influence on the political life of thiscountry. A continuous pouring in ofnational articles by such great patriots as Bankim Chandra Chatterjee, Din Bandhu Mitra, Rabindra NathTagore and Lokmanya Tilak etc, slowly and slowly worked a miracle in rousing political consciousnessamong the Indians and prepare them for the national struggle.
CBSE class 10 solved sample paper for SA2
Muhammad Sahanawaj
Q1)Define evolution.Ans-It a slow gradual process which occurs due to cumulative effects of adaptations and helps it to survive in a better way.Q2)How are fossils helpful in developing evolutionary relationships?Ans: Fossils forms a connecting link between groups of organisms.Q3)Cat’s paw ,human hand and horse’s legs-are these organs homologous or analogous? Give reasonAns- They are homologous organs as they are of same origin performing different functions.origin is forearm modified.Q4)Wings of bird and wings of insect-are these organs homologous or analogous?give one suitable season to support your answer.Ans-They are analogous organs as both have developed fromdifferent origin and perform same function of flying.Q5)Give one difference between eyes and eye spot.Which animal possesses eye spots?Ans-eyes are well developed organs helping to form an image, but eye spots just enable the animalto distinguish between day light and darkness.e.g. planaria and euglena possess eye spotsQ6) Give one difference between artificial selection and natural selection.Ans-Artificial selection is that in which man selects the beneficial gene and modifies it according to his requirement whereas in natural selection nature selects the advantageousgene and helps it to multiply.Q7) What is true- humans have evolved from chimpanzees or humans and chimpanzees both have evolved from a common ancestor?Ans- Both have evolved from a common ancestor because both are existing today .man has not replaced chimpanzees.Q8)What is the mechanism behind the expression of a particular trait?explain briefly.Ans - The mechanism behind the expression of trait is the presence of a functional gene.When gene is functional it is capable of producing a hormone or enzyme which helps in expression of that trait.But sometimes genes get altered and become non-functional,then the enzyme is not produced and the trait does not get expressed.Q9) What will happen to the expression of a particular trait if agene get altered?Ans - When gene gets altered the corresponding enzyme is not produced,hence the hormone related to it is not producedand the particular trait does not expressed.there are chances that instead a disease maybe seen due to altered geneQ10)What are various ways by which genes can enter a population?Ans. The various way area) GENE MIGRATION is gene flow which occurs when some members of main population migrate to other areas and may not come back .this is geographical isolation.b) GENETIC DRIFT -is change in gene frequency due to chance or accident and not by natural selection.c) NATURAL SELECTION-is a process in which better quality genes sekected by nature are allowed to multiply.d) MUTATIONS arise suddenly- they are sudden changes in the gene inherited by offsprings for atleast 4-6 generations.Q11) How will new species arise in case:a) Two sub-populations are separated due to a huge mountain in between them?b) A small population of individuals gets drifted away from the main land due to sea?Ans. New species will arise;a) The huge mountain acts as a geographical barrier and the members of the two sub-population will not be able to mate with one another due to this mountain .this will keep mating within the members of their own sub-population and hence two new species will arise.b) when the small population gets drifted away from main land by sea,here also chances are that there may be some kind of gene flow between the partly separated populations,but if the two populations do not meet, chances are that two new species would arise.Q12) Only advantageous variations help in the evolution of anorganism giving rise to a new species.expalin with the help ofan example.Ans.This is because the advantageous variations are selected by nature and allowed to multiply or propogate fast to increase their members.because such variations help an individual to survive in a better manner in changing environment the population increases.this can be explained as underA- EVOLUTION OF EYE which has occurred bit bt bit and not in one step.even the rudimentary eye was advantageous to Planaria or Octopus even though a clear image was not formed as in humans still it gave a fitness advantage.B-EVOLUTION OF WING-earlier feathers were formed to provide warmth to the body,later these feathers helped in flying.Type-II SHORT ANSWER QUESTIONS (2 marks)1. What are transgenic organisms? Which property of DNA is used as a tool in genetic engineering?Ans. The organisms that contain a segment of foreign DNA are known as transgenic organisms.The complimentary property of the nucleotides of DNA.is the most powerful tool in genetic engineering.2. Explain how the sex of the child is determined at the time of conception in human beings.Ans. Male human beings have XY sex-chromosomes and female human beings have XX sex-chromosomes. If a sperm carrying x-chromosome fertilizes with the ovum, then sex of the baby will be female. If a sperm carrying y-chromosome fuses with the ovum, the sex of the baby will be male.3. By comparing the similarity of nucleotide sequences in DNA of different kinds of organisms, evolutionary relationships can be established.a) Arrange the following according to their evolutionary closeness (You may use your knowledge of classification also) Cockroach, mango tree, gorilla, fish.b) Whose DNA among the following do you think is most similar to that of humans.Ans. a) cockroach – fish – gorilla b) Gorilla4. Mention the ways by which variant genotypes are produced in organism?Ans. a) gene mutation b) Crossing over c) Hybridization5. In human beings blue eye colour is recessive to brown eye colour . If a brown eyed man has a blue eyed mother then finda) What are the possible genotypes of his father?b) What is the genotype of the man and his mother?Ans. BB , Bb B. Man: Bb, mother: bb6. What are fossils? Of what interest are fossils to the evolutionary biologists?Ans. A fossil is the remnant or impression of an organism that lived in the Remote past. Use of Fossilsa)Phylogeny , the evolutionary history can be reconstructed from the fossils.b) The fossil record has helped in building the broad historicalsequence of biological evolution.SHORT ANSWER QUESTION (3 marks)1. a) Who isolated DNA for the first time from pus cells?b) Why is DNA called polynucleotide?c) Name two purine nitrogenous bases found in a DNA molecule.Ans. a) F.Meishcer, named it nuclein.b)DNA is called polynucleolide because it is a polymer or long chain of nucleolide.c)Purine:- Adenine and Guanine.2. a) Who put forward the double helical model of DNA?b) What are the three chemically essential parts of nucleotides constituting a DNA?Ans. a) Watson and Crick.b) Nucleotide constituting –DNA Nitrogen bases (Purines and Pyrimidines),Pentose sugar(Deoxyribose sugar) and a phosphate molecule.3.Guinea pig having black colour when crossed with guinea pig having same colour produced 80 offspring, out of which 60 were black and 20 were white. Now,find out:a)What is the possible genotype of the guinea pigs?b)Which trait is dominant and which trait is recessive?c)What is this cross called as and what is its phenotypic ratio?Ans.a) Bb x Bb b)Black is dominant and white is recessive.c)Monohybrid cross, phenotypic ratio=3:14.Write a brief account on salient points of Lamarck‘s theory. Who disproved this theory?A. Lamarckism1.The use and disuse of an organ leads to acquiring of change in the features of that organ.2. These changes are inherited by the offspring.3. Favourable variations result in evolution of new species. August Weisman.5. Distinguish between acquired and inherited traits giving one example of each.Ans .Acquired traits1) A trait (or characteristic) of a organism which is ‗not inherited‘ but develops in response to the environment is called an acquired trait.(2) The acquired traits of an organism can not be passed on to its future generations. e.g. low weight‘ of beetle, cut tail‘ of a mouse.Inherited traits1) A trait (or characteristic) of an organism which is caused by a change in its genes (or DNA) is called an inherited trait.2) The inherited traits of an organism are passed on to its future generations. e.g. red colour of beetles, fur coat of guinea pigs.LONG ANSWER QUESTIONS – (5marks)1. a. What is genetics?b. Give the common name of plant on which Mendel performed his experiments.c. What for did Mendel use the term factors and what are these factors called now.d. What are genes? Where are the genes located?Ans. A. The branch of biology that deals with the study of heredity and variation.b. Garden pea – Pisum sativum.c. The units of inheritance of characters. These factors are now called as genes.d.Gene is a hereditary unit, a segment of DNA. It is located ona chromosome at a particular locus or position.
Heridity and evolution notes SA2 class10
Class 10 Heredity and Evolution – Gist of lessonGenetics :Branch of science that deals with Heredity and variation.Heredity :It means the transmission of features / characters/ traits from one generation to the next generation.Variation :The differences among the individuals of a species/population are called variations.Mendel and His Work on InheritanceGregor Johann Mendel started his experiments on plant breeding and hybridization. He proposed the laws of inheritance in living organisms. Mendel was known as Father of GeneticsPlant selected by Mendel :Pisum sativum(garden pea). Mendel used a number of contrasting characters for garden pea.Following are the seven pairs of contrasting characters in Garden Pea(TABLE OF CONTRASTING CHARACTERS. SEVEN PARTS)CHARACTERDOMINANT TRAITRECESSIVE TRAITFlower colourVioletWhiteFlower positionAxialTerminalSeed colourYellowGreenSeed shapeRoundWrinkledPod shapeInflatedConstrictedPod colourGreenYellowHeight of plantTallDwarf/ShortMendels Experiments :Mendel conducted a series of experiments in which he crossed the pollinated plants to study one character (at a time)Monohybrid Cross :Cross between two pea plants with one pair of contrasting characters is called a monohybrid cross. Example :Cross between a tall and a draft plant (short).Observations of Monohybrid Cross1. All F1 progeny were tall (no medium height plant (half way characteristic)2. F2 progeny ¼ were short, ¾ were tall3. Phenotypic ratio F2 – 3:1 (3 tall : 1 short)Genotypic ratio F2 – 1 : 2 :1 = TT : Tt : ttConclusions1. TT and Tt both are tall plants while tt is a short plant.2. A single copy of T is enough to make the plant tall, while both copies have to be ‘t’ for the plant to be short.3. Characters/Traits like 'T' are called dominant trait (because it express itself) and ‘t’ are recessive trait (because it remains suppressed)Dihybrid Cross :A cross macle between two plants having two pairs of contrasting characters is called dihybrid cross.PARENT GENERATION--->ROUND GREEN SEEDS xWRINKLEDYELLOW SEEDSPhenotypic RatioObservations1. WhenRRyywas crossed with rrYY in F1 generation all wereRr Yy round and yellow seeds.2. Self pollination of F1 plants gave parental phenotype and two mixtures (recombinants round yellow & wrinkled green) seeds plants in the ratio of 9:3:3:1Conclusions1. Round and yellow seeds areDOMINANTcharacters2. Occurrence of new phenotypic combinations show that genes for round and yellow seeds areinherited independentlyof each otherSEX DETERMINATION :Phenomenon of decision or determination of sex of an offspringFACTORS Responsible for Sex Determination1. Environmental : In some animals the temperature at which the fertilised eggs are kept decides the gender. eg. in Turtle 2.Genetic : In some animals like humans gender or individual is determined by a pair of chromosome called sex chromosome XX – Female and XY – MaleThis shows that half the children will be boys and half will be girls. All children will inherit an X chromosome from their mother regardless whether they are boys or girls. Thus sex ofchildren will be determined by what they inherit from their father, and not from their mother.EVOLUTIONEvaluation is the sequence of gradual changes which takes place in the primitive organisms, over millions of years, in which new species are produced.Situation-IGroup of red beetlesColour variation arises during reproductionAll beetles red except one that is greenOne beetle Green ReproductionCrows feed on red beetleProgeny beetles greenNo. of beetles reducesCrow could not feed on green beetles as they got camouflaged in green bushesNumber of green beetles increasesSituation 1 :Green beetles got the survival advantage or they were naturally selected as they were not visible in green bushes. This natural selection is exerted by crows resulting inadaptations in the beetles to fit better in their environmentSituation 2 :Blue beetles did not get survivals advantage. Elephant suddenly caused major havoc in beetle population otherwise their number would have been considerably large.From this we can conclude that accidents can change the frequency of some genes even if they do not get survival advantage: This is called genetic drift and it leads to variation.Characters or traits of an organism are controlled by the genesA Section of DNA (cellular)GeneProvides informationFor synthesis of ProteinsProteins controls a characterExample :Gene Tresponsible for synthesis of efficient enzyme (Protein)More productionof growth hormoneResults in Tall PlantsGene tresponsible for synthesis of less efficient enzymeLess productionof growth hormoneResults in short PlantsGenetic drift. It leads to diversity without any adaptationSITUATION-IIIGroup of red beetlesHabitat of beetles (bushes)Suffer from plant diseaseAverage weight of beetlesdecreases due to poor nourishmentNumber of beetles kept on reducingLater plant disease gets eliminatedNumber and average weight of the beetles increases againSituation 3 :No genetic change has occurred in the population of beetle. The population gets affected for a shortduration only due to environmental changes.ACQUIRED AND INHERITED TRAITSAcquired TraitsInherited Traits1. These are the traits which are developed in an individual due to special conditions1. These are the traits which are passed from one generation to the next.2. They cannot be transferred to the progeny2. They get transferred to the progeny.3. They cannot direct evolution eg. Low weight of starving beetles.3. They are helpful in evolution. eg. Colour of eyes and hairSPECIATIONMicro evolution : It is the evolution which is on a small scale. eg. change in body colour of beetles.The process by which new species develop from the existing species is known as speciation.Speciation : it is the process of formation of new species.Species : A group of similar individuals within a population that can interbreed and produce fertile offspring.Geneflow : It is exchange of genetic material by interbreedingbetween populations of same species or individualsWAYS BY WHICH SPECIATION TAKES PLACESpeciation takes place when variation is combined with geographical isolation.Gene flow :occurs between population that are partly but not completely separatedGENETIC DRIFTIt is the random change in the frequency of alleles (gene pair) in a population over successive generations.*Natural Selection :The process by which nature selects and consolidate those organisms which are more suitably adapted and possesses favorable variationsGenetic drift takes place due to(a) Severe changes in the DNA (b) Change in number of chromosomesEvolution and classificationBoth evolution and classification are interlinked.1. Classification of species is reflection of their evolutionary relationship.2. The more characteristic two species have in common the more closely they are related.3. The more closely they are related, the more recently they have a common ancestor.4. Similarities among organisms allow us to group them together and to study their characteristic.TRACING EVOLUTIONARY RELATIONSHIPS(Evidences of Evolution)I. Homologous Organs :(Morphological and anatomical evidences. These are the organs that have same basic structural plan and origin but different functions.Homologous organs provides evidence for evolution by telling us that they are derived from the same ancestor.Example :Forelimb of Horse(Running)Same basic structural but different functions perform.Winds of bat(flying) plan,Paw of a cat(walk/scratch/attack)II. Analogous Organs :These are the organs that have different origin and structural plan but same function example :Example :Analogous organs provide mechanism for evolution.Wings of bat elongated fingers with skin foldsWings of bird Feathery covering along the armDifferent basic structure, but perform similar function i.e., flightIII. Fossils :(Palaeontological evidences) : The remains and relics of dead organisms of the past.FOSSILS ARE PRESERVED TRACES OF LIVING ORGANISMSFossil Archaeopteryx possess features of reptiles as well as birds. This suggests that birds have evolved from reptiles.Examples of FossilsAMMONITE - Fossil-invertebrateTRILOBITE - Fossil-invertebrateKNIGHTIA - Fossil-fishRAJASAURUS - Fossil dinosaur skullAGE OF THE FOSSILSI. Deeper the fossil, older it is.II. Detecting the ratios of difference of the same element in the fossil material i.e.Radio-carbon dating[C-(14) dating)Evolution by stages :Evolution takes place in stages ie bit by bit over generations.I. Fitness advantageEvolution of EyesEvolution of complex organs is not sudden it occurs due to minor changes in DNA, however takes place bit by bit over generations.Flat worm has rudimentary eyesInsects have compound eyesenough to give fitness advantageHumans have binocular eyesII. Functional AdvantageEvolutions of feathers :Feathers provide insulation in cold weather but later they might become useful for flight.Example :Dinosaurs had feathers, but could not fly using feathers. Birds seem to have later adapted the feathers to flight.Evolution by Artificial Selection :Humans have been a powerful agent in modifying wild species to suit their own requirement throughout ages by using artificial selection. eg(i) From wild cabbage many varieties like broccoli, cauliflower, red cabbage, kale, cabbage and kohlrabi were obtained by artificial selection.(ii) Wheat (many varieties obtained due to artificial selection).Molecular PhylogenyÞIt is based on the idea that changes in DNA during reproduction are the basic events in evolutionÞOrganisms which are more distantly related will accumulategreater differences in their DNA
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