Thursday, 7 January 2016

NCERT Solutions for Class 11th: Ch 1 From the Beginning of Time History

NCERT Solutions for Class 11th: Ch 1 From the Beginning of Time History

Page No: 28

Exercises

Answer in brief

1. Look at the diagram showing the positive feedback mechanism on page 13. Can you list the inputs that went into tool making? What were the processes that were strengthened by tool making?


Diagram of Positive feedback mechanism

Answer

The inputs that  helped in making tools:
(a) Bipedalism which led to freeing of hands.
(b) Large brain size and increased capability

The processes which were strengthened by the making of tools were:
(ii) The capability and mental capacity of men.
(ii) Tool making strengthened  man’s technical skills.
(iii) Created conditions from the transition from scavenging to hunting.
(iv) Man could trap fur bearing animals and use the fur for clothing.
(v) Introduction of punch blade technique to make small chisel.
(vi) Tools helped primitive man in farming, development of agriculture and lead a settled instead of nomadic life.

2. Humans and mammals such as monkeys and apes have certain similarities in behaviour and anatomy. This indicates that humans possibly evolved from apes. List these resemblances in two columns under the headings of (a) behaviour and (b) anatomy. Are there any differences that you think are noteworthy?

Answer

Humans and mammals such as monkey and apes have certain similarities in behaviours and anatomy.
This shows that humans possibly evolved from apes.

Similarities on the basis of behavior:
(i) Both can climb on trees.
(ii) Both secrete milk and carry their babies with them .
(iii) Both can run and walk.
(iv) Both use sound as a mode of communication.

Similarities on the basis of anatomy:
(i) They have warm blood and body hair are present on body.
(ii) They have different types of teeth.
(iii) Both are vertebrates .
(iv) Both have two feet and two hands.

Differences on the basis of behavior:
(i) Human beings earn money for their families but monkey and apes  do not perform economical activities.
(ii) Humans walks upright while monkey any and apes cannot walks upright.
(iii) Humans prepare tools themselves while monkeys and apes  not prepare themselves.
(iv) Human walks on two feet while monkey and apes walks on four feet.

Differences on the basis of anatomy:
(i) Humans have large body as compared to apes and monkeys.
(ii) Monkeys and apes have tails while humans have no tail.

3. Discuss the arguments advanced in favour of the regional continuity model of human origins. Do you think it provides a convincing explanation of the archaeological evidence? Give reasons for your answer.

Answer

Two different views have been expounded regarding human origins:
(i) Regional continuity model - According to this human has multiple origin.        
(ii) Replacement model - According to this human has single origin.
(iii) Regional Continuity Model - According to this, modern homo sapiens evolved in different regions at different rates. So there was a difference in appearance of human in different parts of world.it was based on regional difference in the features of present days humans. The dissimilarities are due to the differences between the homo-erectus and homo heidelbergensis population of same regions.
The regional continuity model does not give a convincing explanation of the archaeological evidences.

4. Which of the following do you think is best documented in the archaeological record: (a) gathering, (b) tool making, (c) the use of fire?

Answer

Tool making is documented in the archaeological record.

Answer in a short Essay

5. Discuss the extent to which (a) hunting and (b) constructing shelters would have been facilitated by the use of language. What other modes of communication could have been used for these activities?

Answer

Early man was food gatherer and scavengers. These were the more of an individual’s activities.With homo- erectus social groups because larger and man matured from being a scavenger to hunting.
• Hunting activities of human:
(i) They could also discuss about the nature and behaviour of animals.
(ii) They can also discuss nature of tools used in hunting.
(iii) They can exchange ideas where the specific animals were found
(iv) People now could organise and manage hunting expeditions.

• Construction of shelters by human beings:
(i) People now could discuss secure places for construction of their shelter.
(ii) They could  now get information about the resources  available around their  surroundings.
(iii) People  become edible to get knowledge about the materials used for places for construction of their shelter.
(iv) Their could also discuss the means to protect their shelter from severe condition.
Signs, symbols , oral, voice shouting, cave painting, engraving on the walls and ceiling on the caves are the other useful modes of communication used for these activities.

6. Choose any two developments each from Timelines 1 and 2 at the end of the chapter and indicate why you think these are significant.

Answer

• First Development in timeline-1 (MYA):
It is an anatomical ana physiological change that could take place after a long duration of 12 mya. The monkey in south Africa could become African ape our ancestor.

• Second Development in timeline-1 (MYA):
It took place due to tropical climate formed and Australopithecus turned into the genes homo . It took time about 3 million- 5.6 - 2 mya

Development in timeline-2:
(i) The first development related to vocal cord in human anatomy far back in 2 lakhs year ago. It greatly helped in the development of skill and expertise in doing things easier than the period ,human had not vocal cord.
(ii) The second important development that could be constructed the period of 21  thousand years ago when sewing needles were invented .This invention of sewing needles brought revolution in the fields of growing cotton, jute, silk etc. Fibre crops, weaving, spinning etc.

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