Concise Biology Class 10 ICSE Solutions for Chapter 14 - Pollution - Human Evolution

A. Multiple choice questions

1. The first scientist who proposed his theory for evolution was

(a) Darwin

(b) Mendel

(c) Lamarck

(d) Wallace

Ans: (c) Lamarck

2. The theory of Natural Selection was proposed by

(a) Mendel

(b) Lamarck

(c) Wallace

(d) Darwin

Ans: (d) Darwin

3. The organism studied for industrial melanism was a

(a) Butterfly

(b) Moth

(c) Honeybee

(d) Cockroach

Ans: (b) Moth

4. Identify the pre-human ancestor.

(a) Ramapithecus

(b) Australopithecus

(c) Neanderthal man

(d) Cro-Magnon

Ans: (a) Ramapithecus

B. Short Answer Type

1. Why do Neanderthal man and modern man belong to two distinct species?

Ans: Different types of characteristics are exhibited by Neanderthal man and the modern man. The different characteristics are listed below:

2. The range of cranial capacities in the following ancestral forms were

(a) Australopithecus

(b) Homo habilis

(c) Homo erectus

(d) Cro-magnon

(e) Homo sapiens sapiens

Ans: The ranges are mentioned in the table below: 

3. Mention the two principles through which Lamarck explained his ideas.

Ans: The two principles through which Lamarck explained his ideas were: 

(a) Use and Disuse: The parts of the body that are used on daily basis grow stronger and the parts that are used less start to deteriorate. 

(b) Inheritance of Acquired Characters: The acquired characteristics from an organism are passed onto the next generation. 

4. Name any three vestigial organs found in humans.

Ans: Three vestigial organs found in humans are wisdom teeth, vermiform appendix, and pinna.

5. Give the scientific name of the organism which is cited as the classical example of 'natural selection.

Ans: Biston betularia is a classical example of 'natural selection.

6. Tick mark (√) the correct option in the following statements.

(a) The fossil history of humans is complete/fragmentary.

Ans: (a) The fossil history of humans is fragmentary.

(b) The first remarkable human fossil was that of H. habilis/H. Africanus.

Ans: (b) The first remarkable human fossil was that of Homo habilis.

(c) Evolution is an ever-continuing/promptly ending process.

Ans: (c) Evolution is an ever-continuing process. 

C. Descriptive Type

1. Define the following terms:

(a) Evolution

Ans: (a) Evolution: Evolution is a very slow process. It is a continuous process and very complex process. With the help of this process, complex life forms are formed in the millions of years. 

(b) Vestigial organs

Ans: (b) Vestigial organs: Vestigial organs are those organs that have ceased to be of any use to the possessor but still persist generation after generation in a reduced form.

(c) Speciation

Ans: (c) Speciation: Speciation is a process of origin of new species by gradual modification. 

2. Distinguish Between

(a) Australopithecus and Cro-magnon (Chin)

Ans: (a) Difference between Australopithecus and Cro-magnon (Chin):

(b) Australopithecus and Modern man (Body hair)

Ans: (b) Difference between Australopithecus and Modern man (Body hair):

(c) Homo habilis and Homo sapiens (Posture)

Ans: (c) Difference between Homo habilis and Homo sapiens (Posture):

3. Differentiate between Lamarck's Theory and Darwin's Theory.

Ans: Differences between Lamarck's Theory and Darwin's Theory:

4. Explain four observable facts on which the "Theory of Natural Selection" is based.

Ans: The Darwin's theory of Natural Selection is based on four observable facts which are as follows:

(i) Overproduction:

• 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.

(iii) Variation:

∙ 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 favorable characteristics will survive in the long run. This idea is called 'Survival of the fittest.

• Organisms that survive will transmit favorable characteristics to their offspring.

• These characters get accumulated and give rise to new species.

5. Industrial melanism provides a good example of natural selection. Discuss.

Ans: The best example is industrial melanism. It shows the effect of industrial pollution on the moth population on a nearby tree. Before industrialization, light-colored 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, when the industrial pollution took place, 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 melanism. Before industrialization, white moths were better adapted towards nature, but after industrialization, dark-colored moths were more fit towards the changed environmental conditions.

D. Structured/Application/Skill Type

1. 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.

Ans: 

Stage A: Australopithecus

Stage B: Homo sapiens sapiens

(a) Contrasting characters between Australopithecus and Homo sapiens:

(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

2. 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?

Ans: (a) Industrial melanism

(b) Give the common name and the scientific name of the insect involved in this phenomenon.

Ans: (b) Common name: Peppered moth

Scientific name: Biston betularia

(c) Briefly mention why the changes shown in the two figures appeared.

Ans: (c) Reasons for changes in the two figures:

Before the Industrial Revolution, a thick growth of white-colored lichen covered the trees. As a result, the light-colored moths were camouflaged and survived under this cover, while the dark-colored 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-colored moths now got an advantage of a dark background, were camouflaged, and survived, while the light-colored 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.

(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.

Ans: 

(d) (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

Introduction

Vedantu provides the latest ICSE Class 10 Biology Chapter 14 - Human Evolution step-by-step solutions. Selina is the most famous publisher of ICSE textbooks. The solutions of the Selina biology book are explained and solved by experts in this field who will help the students prepare for ICSE exams. Concise Biology Class 10 ICSE Solutions is easy to download in the specified PDF format. These ICSE Class 10 solutions will help the students get good grades in the ICSE exams. The updated solutions in Selina textbooks are made according to the latest curriculum. They are given in Vedantu chapter by chapter to help students learn the basics thoroughly.

Human Evolution

By human evolution, we understand the process in which people evolve from one version to another through the course of time. The process of evolution is really long and takes thousands of years.