Human Evolution ICSE Class-10 Concise Selina Biology
Human Evolution ICSE Class-10 Concise Selina Biology Solutions Chapter-14 .We Provide Step by Step Answer of Progress Check , MCQs, Very Short Answer Type, Short Answer Type, Long Answer Type Questions and Structured / Applications / Skill Type Questions of Exercise-14 Human Evolution ICSE Class-10 . Visit official Website CISCE for detail information about ICSE Board Class-10.
Human Evolution ICSE Class-10 Concise Selina Biology Solutions Chapter-14
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Chapter-14,Human Evolution Selina Biology Solution for ICSE Class 10
A. MULTIPLE CHOICE TYPE
The first scientist who proposed his theory for evolution was
The theory of Natural Selection was proposed by
The organism studied for industrial melanism was a
Identify the pre-human ancestor.
(c) Neanderthal man
Human Evolution Concise Biology Solution for ICSE Class 10 Chapter-14
B. SHORT ANSWER TYPE
Why Neanderthal man and modern man belong to two distinct species?
Neanderthal man and modern man exhibit different characteristics, and hence, they are considered two distinct species. Below are the characteristic differences between Neanderthal man and modern man:
|Characteristics||Neanderthal man||Modern man|
|Locomotion||Absolute bipedalism||Bipedal locomotion|
|Head and forehead||Large head, broad, flat and sloping forehead||Upright head, skull on the top of the vertebral column, steep forehead|
|Brow ridges||Prominent brow ridges||Reduced brow ridges|
|Chin||No chin||Well developed and prominent chin|
|Hair on body||Less hair on the body||Prominent hair on limbs|
|Cranial capacity||1450 cm3||1450 to 1600 cm3|
The range of cranial capacities in the following ancestral forms were
(b) Homo habilis
(c) Homo erectus
(e) Homo sapiens sapiens
|Ancestral forms||Cranial capacities|
|(a) Australopithecus||450 to 600 cm3|
|(b) Homo habilis||680 to 735 cm3|
|(c) Homo erectus||800 to 1125 cm3|
|(d) Cro-magnon||1450 to 1600 cm3|
|(e) Homo sapiens sapiens||1450 to 1600 cm3|
Mention the two principles through which Lamarck explained his ideas.
(a) Use and disuse:
Parts of the body which are used extensively become larger and stronger, while those which are not used deteriorate.
(b) Inheritance of acquired characters:
An organism could pass its modifications to its offspring.
Name any three vestigial organs found in humans.
Three vestigial organs found in humans are wisdom teeth, vermiform appendix and pinna.
Give the scientific name of the organism which is cited as the classical example of ‘natural selection’.
Biston betularia is a classical example of ‘natural selection’.
Tick mark (√) the correct option in the following statements.
(a) The fossil history of humans is complete/fragmentary.
(b) The first remarkable human fossil was that of H. habilis/H. africanus.
(c) Evolution is an ever continuing/promptly ending process.
(a)The fossil history of humans is fragmentary.
(b)The first remarkable human fossil was that of Homo habilis.
(c)Evolution is an ever continuing process.
Concise Biology Solution for ICSE Class 10 Chapter-14 Human Evolution
C. LONG ANSWER TYPE
Briefly discuss the Theory of Natural Selection as given by Darwin.
Charles Darwin proposed the idea of natural selection. Darwinism or Theory of Natural Selection is based on some facts:
All organisms have the capacity to reproduce at a very high rate.
However, organisms cannot survive by reproduction alone.
Due to lack of food and space, offspring soon begin to die.
Some are eaten by predators, while some get destroyed due to adverse environmental conditions.
(ii) Struggle for existence:
Overproduction of organisms results in a struggle for existence among organisms.
The struggle is to obtain food, space and mate.
Progeny of the same parents are not exactly alike. Such differences are known as variations. The variations may be harmful or advantageous.
(iv) Survival of fittest:
In the struggle for existence, organisms that develop new favourable characteristics will survive in the long run. This idea is called ‘Survival of the fittest’.
Organisms which survive will transmit favourable characters to their offspring.
These characters get accumulated and give rise to new species.
Industrial melanism provides a good example of natural selection. Discuss.
The best example is industrial Melanesian showing the effect of industrial pollution on the moth population on a nearby tree.
Before industrialization, light-coloured lichen used to grow on trees and moth predators could not spot white moths easily, while dark moths were lesser in the moth population. However, due to industrial pollution, lichens could not grow on trees and it became difficult for predators to spot dark moths on the dark background of the stem bark, and thus, the population of white moths became less than that of dark moths.
This process is termed industrial melanin. Before industrialization, white moths were better adapted towards nature, but after industrialization, dark-coloured moths were more fit towards the changed environmental conditions.
How would you justify that Australopithecus was a human ancestor?
Australopithecus averaged about 120 cm tall, and the cranial capacity ranged from 450-600 cm3. It had a low forehead, protruding face, lack of chin and low brain capacity. Teeth resembled man because the dental arc was a smoothly rounded parabola, and a simian gap was absent which justifies a human ancestor.
Name the six ancestral forms in their correct sequence through which modern man has evolved.
Correct sequence through which modern man evolved:
- Homo erectus
- Neanderthal man
- Homo sapiens
Briefly discuss Lamarckian Theory of Inheritance citing an appropriate example.
According to the theory of inheritance of acquired characters, ‘the changes in structure or function of any organ acquired during the life-time of an individual in response to changes in the surrounding environment are inherited by offspring and keep on adding over a period of time’.
This theory states that characters are acquired by animals in two ways:
– Effects of environment
– Use and disuse of body parts
For example, the long neck of giraffe is explained by Lamarck on the same principle. Giraffe, which lived in the dry and arid deserts of Africa, tried to reach the foliage high up on the trees to eat them as there was no vegetation on the ground. In the process, its neck and forelegs got stretched a bit and this was inherited by the next generation. Then, in the next generation, the same efforts continued. Gradually, through many successive generations, we got a giraffe having a long neck and long forelegs.
Explain the occurrence of vestigial organs on the basis of Lamarck’s theory of use and disuse.
Organs which are found in reduced or rudimentary condition and do not perform any function in the possessor are called vestigial organs or non-functional organs. They help in understanding the history of evolution and continuity of life.
Wisdom teeth: They are the last molars which appear last at the age of 17-20 years.
Vermiform appendix: It projects from the blind end of the caecum and is a functionless organ in humans. It is helpful in herbivorous mammals.
Pinna: It is the lobe-like part of the external ear which humans cannot move as in other mammals. As it is poorly developed, it is a vestigial organ.
Selina Biology Solution for ICSE Class 10 Chapter-14 Human Evolution
Given alongside are two figures (A and B) representing the two stages of evolution of human beings.
Answer the following:
(a) Mention any two contrasting characters between the two stages.
(b) Write all the stages of human evolution in their correct sequence.
(c) State any two characteristic features of stage B.
Stage A: Australopithecus
Stage B: Homo sapiens sapiens
(a) Contrasting characters between Australopithecus and Homo sapiens sapiens:
|Cranial capacity||450 to 600 cm3||1450 to 1600 cm3|
|Development of chin||Lack of chin, prognathous face||Prominent chin, snout disappeared|
(b) Stages of human evolution in their correct sequence:
Australopithecus ® Homo habilis ® Homo erectus ® Neanderthal man ® Cro-Magnon man ® Homo sapiens sapiens
(c) Characteristic features of stage B (Homo sapiens sapiens):
Bipedal locomotion with four reversed curves in the spine
Forehead steep, reduced brow ridges
Given alongside are two figures (A and B) showing a phenomenon that was first observed in Manchester before and after the year 1850.
Answer the following.
(a) What name has been given to this phenomenon?
(b) Give the common name and the scientific name of the insect involved in this phenomenon.
(c) Briefly mention why the changes shown in the two figures appeared.
(d) The following phenomenon provides a classical explanation of a scientific theory given by a certain scientist. (i) Name and explain the said theory.
(ii) Give the name of the scientist who gave this theory.
(a) Industrial melanism
(b) Common name: Peppered moth
Scientific name: Biston betularia
Reasons for changes in the two figures:
Before the Industrial Revolution, a thick growth of white-colouredlichen covered the trees. As a result, the light-coloured moths were camouflaged and survived under this cover, while the dark-coloured moths were easily spotted by predators.
After the Industrial Revolution, pollution resulted in a decline in the growth of lichens. The tree bark got exposed due to the absence of lichens. As a result, dark-colouredmoths now got an advantage of a dark background, were camouflaged and survived, while the light-coloured moths were easily picked by predators.
This showed that in a mixed population, those moths which could adapt to the changing environment after the Industrial Revolution survived and increased in number,while the ones which could not adapt were slowly wiped out from the population.
(i) Natural selection
During the struggle for existence, only those individuals which have advantageous variations survive while the ones which lack these variations are wiped out. Nature selects only those variations which are suitable for existence. This process is called natural selection.
- (ii) Charles Darwin
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