Chapter 11 – Evolution and Adaptation

Getting ready for your WBBSE Class 10 Geography exam? The topic Evolution and Adaptation is very important and often comes in exams. Here, you will find important questions and answers written in simple and easy English. These questions are selected from important topics and previous year trends. This will help you learn quickly, revise easily, and score good marks in your Madhyamik exam.

Content Structure

1. Multiple choice questions and answers (MCQs)
2. Very short-type questions and answers
- 2A. Fill in the blanks
- 2B. True or false
- 2C. Single word questions and answers
3. Short-type questions and answers
4. Long-type questions and answers

1. Multiple choice questions and answers (MCQs)

1. The earth originated –
(a) 2.6 billion years ago
(b) 4.6 billion years ago
(c) 8.5 billion years ago
(d) 10.4 billion years ago

Ans: (b) 4.6 billion years ago

2. Life originated first-
(a) On land
(b) In air
(c) In water
(d) On mountain

Ans: (c) In water

3. Analogous structures are –
(a) Structurally similar
(b) Structually and functionally similar
(c) Functionally similiar
(d) Normally non-functional

Ans: (c) Functionally similiar

4. When the organs of living body are similar in origin but different in shape, size and functions they are called-
(a) Homologous organ
(b) Analogous organ
(c) Functionless organ
(d) Vestigial organ

Ans: (a) Homologous organ

5. Vestigal organ in cassia is-
(a) Calyx
(b) Ovary
(c) Corolla
(d) Stamens

Ans: (d) Stamens

6. “Inheritance of Acquired Character” was proposed by-
(a) Darwin
(b) Hugo de veries
(c) Lamarck
(d) Malthus

Ans: (c) Lamarck

7. Theory of natural selection was put forward by –
(a) Wallace
(b) de vries
(c) Darwin
(d) Lamarck

Ans: (c) Darwin

8. The theory of use and disuse was given by-
(a) Stebbins
(b) Lamarck
(c) Vavilov
(d) Darwin

Ans: (b) Lamarck

9. Who believed that an organ in disease will become vestigial?
(a) Lamarck
(b) de vries
(c) Mendel
(d) Darwin

Ans: (a) Lamarck

10. ‘Philosophic Zooligique’ was written by-
(a) de veries
(b) Lamarck
(c) Mendel
(d) Spencer

Ans: (b) Lamarck

11. ‘Origin of species’ was written by-
(a) Oparin
(b) Weismann
(c) Lamarck
(d) Darwin

Ans: (d) Darwin

12. ‘Survival of the fittest’ was used by-
(a) Carles Darwin
(b) Jean Baptiste Lamarck
(c) Hugo de veries
(d) Herbert Spencer

Ans: (d) Herbert Spencer

13. The book on the “Origin of spices” was written by Darwin in the year-
(a) 1831
(b) 1849
(c) 1869
(d) 1859

Ans: (d) 1859

14. A fossile is a-
(a) Laboratory preserved animal
(b) Organic relic of the past
(c) Stuffed animal
(d) Dead animal of the past

Ans: (b) Organic relic of the past

15. The theory of the origin of life was first proposed by-
(a) Oparin
(b) Mendel
(c) Pasteur
(d) Darwin

Ans: (a) Oparin

16. Scientist Stanley Miller was able to synthesize simple amino acids from a mixture of-
(a) H2, )2, N2 and H2O
(b) H2, NH3, CH4, and H20
(c) NH3, CH4, HCN
(d) N2, NH3, HCN and O2

Ans: (b) H₂, NH₃, CH₄ and H₂O

17. Who was the first disapproved the doctrine of spontaneous generation of life?
(a) Louis Pasteur
(b) Miller
(c) Alexender Oparin
(d) Aristotle

Ans: (a) Louis Pasteur

18. The cause of biodiversity on earth is –
(a) Metabolism
(b) Locomotion
(c) Adaptation
(d) Evolution

Ans: (d) Evolution

19. The study of development of an organism in its life-span is called-
(a) Ontogeny
(b) Organic evolution
(c) Mutation
(d) Special creation

Ans: (a) Ontogeny

20. The term evolution is coined by-
(a) Darwin
(b) Herbert Spencer
(c) Hugo de Vries
(d) Lamarck

Ans: (b) Herbert Spencer

21. Which of the following can be explained by the theory of natural selection?
(a) Over specialisation
(b) Discrete Variation
(c) Survival of the fittest
(d) Vestigial organ

Ans: (c) Survival of the fittest

22. Who first used the statement struggle for existence?
(a) Lamarck
(b) Weismann
(c) Mendel
(d) Darwin

Ans: (d) Darwin

23. Determine the term related to the theory of Lamarck. [Madhyamik 19]
(a) Origin of variation
(b) Struggle for existence
(c) Natural selection
(d) Inheritance of acquired characters

Ans: (d) Inheritance of acquired characters

24. Who proposed the germplasm concept?
(a) Spencer
(b) Weismann
(c) Goldsmith
(d) Hugo de Vries

Ans: (b) Weismann

2. Very short-type questions and answers

2A. Fill in the blanks

1. The age of the earth is about __________ million years. (4600)
2. Coal is the _______ of plants. (fossil fuel)
3. _________ is the modern horse. (Equus)
4. Rhynia and philophyton are the Devonian __________ is the fossile plants. (age)
5. __________ was born at Bajastin in France in 1744.(Jean Baptiste Lamarck)
6. The theory of Lamarck is known as ___________. (inheritance of acquired characters)
7. Origin same but function different is known as _________. (homologous organs)
8. Function same but origin different is known as ____________- organ. (analogous)
9. _________ acts as connecting link between reptile and mammal.(Duck-billed platypus)
10. __________ was the ancestor of the modern horses.(Eohippus)
11. Natural selection theory was proposed by ____________.(Charles Darwin)
12. The impression of organisms over stone is called _____________.(impression fossil)
13. Equisetum plant is an example of ___________. (living fossil)
14. Nictitating membrane is a ____________.(vestigial organ)
15. Name of a missing link is _____________.(Archaeopteryx)
16. ______________ is the name of a fossil plant.(Rhynia)
17. __________ islands are located nearest the West Coast of South America. (Galapagos)
18. Organism exists both as fossil and living are termed ______ ___________. (living fossils)
19. Germ plasm concept is proposed by _____________. (August Weismann)
20. It is now proven that inheritance of acquired characters occurs only by __________ cells. (germ)
21. Coccyx is a ____________ organ of human body. (vestigial)
22. Heart of fish carries deoxygenated blood only therefore it is known as ____________ heart. (venous)

2B. True or false

1. According to some scientists the dust particles of universe condensed to form earth. (True)
2. The first formed life was photosynthetic. (False)
3. Miller proposed the theory of coacervate. (False)
4. Darwin coined the term ‘evolution’. (False)
5. The materials necessary for the origin of life was present on landmass of the primitive earth. (False)
6. Protocells originated by the association of nucleic acid with coacervates. (True)
7. Miller and urey experimentaly proved the chemosynthetic origin of life on earth. (True)
8. The concept of survival of the fittest is proposed by Lamarck. (False)
9. Darwin authored the famous book, ‘Origin of Life’. (False)
10. Lamarck proposed the concept of survival of the fittest. (False)
11. The wings of birds and insects are examples of analogous organ. (True)
12. The organs of different organisms. having same origin and fundamental structure but performing different functions are called analogous organs. (False)
13. Staminodes of Cassia are its vestigial organs. (True)

2C. Single word questions and answers

1. Where was life first created?
Ans: Life first originated in the primitive oceans.

2. Write the name of a book written by Charles Darwin.
Ans: On the Origin of Species is a book written by Charles Darwin.

3. Origin of species by natural selection – who suggested this concept?
Ans: Charles Darwin suggested the concept of origin of species by natural selection.

4. Why is the year 1859 famous in evolutionary history?
Ans: Darwin’s book The Origin of Species was published in 1859.

5. How many types of variations are there?
Ans: There are two types of variations – continuous and discontinuous.

6. Give an example of a homologous organ.
Ans: The forelimbs of man, horse, whale and bat are homologous organs.

7. Give example of an analogous organ.
Ans: The wings of birds and wings of insects are analogous organs.

8. Give example of two vestigial organs in man.
Ans: Appendix and wisdom teeth are vestigial organs in man.

9. In which group of animals is the heart two-chambered?
Ans: The heart is two-chambered in fishes.

10. In which group of animals is the heart three-chambered?
Ans: The heart is three-chambered in amphibians and most reptiles.

11. Give an example of an animal fossil.
Ans: Archaeopteryx is an example of an animal fossil.

12. Name a mammal which lays eggs.
Ans: Duck-billed platypus lays eggs.

13. Name the fossil of the oldest forefather of horse.
Ans: Eohippus is the fossil of the oldest forefather of horse.

14. Who proposed the concept of struggle for existence?
Ans: Charles Darwin proposed the concept of struggle for existence.

15. What is the full name of Lamarck?
Ans: The full name of Lamarck is Jean-Baptiste de Lamarck.

16. Name the famous book written by Charles Robert Darwin.
Ans: The Origin of Species is the famous book written by Darwin.

17. Who is the propounder of inheritance of acquired characters?
Ans: Jean-Baptiste Lamarck is the propounder.

18. In which year was Darwin’s natural selection theory published?
Ans: Darwin’s theory of natural selection was published in 1859.

19. Where did life originate?
Ans: Life originated in water.

20. Which period is called the age of reptiles?
Ans: The Mesozoic era is called the age of reptiles.

21. Which era is called the age of mammals?
Ans: The Cenozoic era is called the age of mammals.

22. Which group of animals has venous heart?
Ans: Fishes have a venous heart.

23. Which reptile has a four-chambered heart?
Ans: Crocodile has a four-chambered heart.

24. What type of organs are the wings of birds and insects?
Ans: The wings of birds and insects are analogous organs.

25. What is the alternative name of biogenetic law?
Ans: The biogenetic law is also called the Recapitulation theory.

26. Which is the vestigial organ of kiwi?
Ans: Wings are vestigial in kiwi.

27. Which digit of a horse is modified into hoof?
Ans: The third digit is modified into hoof.

28. Which is the vestigial organ of ostrich?
Ans: Wings are vestigial organ in ostrich.

29. Name the connecting link between gymnosperms and angiosperms.
Ans: Gnetum is the connecting link between gymnosperms and angiosperms.

30. Who is known as the father of evolution?
Ans: Charles Darwin known as the father of evolution.

31. Who proposed the mutation theory?
Ans: Hugo de Vries proposed the mutation theory.

32. What is the struggle for food and shelter called?
Ans: The struggle for food and shelter is called the struggle for existence.

33. Name a scientist who supported Neo-Lamarckism.
Ans: Cope was a scientist who supported Neo-Lamarckism.

34. What is the main criterion of survival of the fittest?
Ans: Adaptation to the environment is the main criterion of survival of the fittest.

35. Write one limitation of Darwinism.
Ans: Darwinism could not explain how variations originate in organisms.

36. Write two reasons for evolution.
Ans: Variation and natural selection are two reasons for evolution.

37. Who proposed the concept of microsphere?
Ans: Sidney Fox proposed the microsphere concept.

38. Who first introduced the concept of coacervate?
Ans: Oparin introduced the concept of coacervate.

3. Short-type questions and answers

1. What is meant by organic evolution?
Ans: Organic evolution is the slow and continuous process by which simple organisms gradually change over many generations to form new and more complex species.

2. What is petrification?
Ans: Petrification is the process by which the soft parts of dead organisms are replaced by minerals to form fossils.

3. What are the theory of abiogenesis and biogenesis?
Ans: The theory of abiogenesis states that life originated from non-living matter under suitable conditions, whereas the theory of biogenesis states that life originates only from pre-existing living organisms.

4. What is fossil?
Ans: A fossil is the preserved remains, impressions, or traces of plants and animals that lived in the ancient geological past and are found in sedimentary rocks.

5. What is a living fossil?
Ans: A living fossil is an organism that has survived from ancient times without much change, like Limulus.

6. What do you mean by missing link?
Ans: A missing link is an organism that shows characteristics of two different groups and connects them evolutionarily.

7. Give an example of an animal as missing link.
Ans: Archaeopteryx is an example of a missing link between reptiles and birds.

8. Mention three reptilian features of Archaeopteryx.
Ans: The reptilian features of Archaeopteryx are:

Presence of clawed fingers on the forelimbs
Presence of teeth in the jaws
Presence of a long bony tail

9. Write three Avian features of Archaeopteryx.
Ans: The avian features of Archaeopteryx are:

Presence of a bird-like skeleton
Presence of feathers
Forelimbs modified into wings

10. What is the relation between adaption and evolution?
Ans:

Adaptation	Evolution
Adaptation helps organisms survive in a particular environment.	Evolution occurs when adaptations accumulate over many generations.
Adaptations are short-term changes.	Evolution is a long-term process.
Adaptation is a part of evolution.	Evolution is the result of continuous adaptation.

11. Why is Lamarck famous?
Ans: Lamarck is famous because he proposed the theory of inheritance of acquired characters, which states that characters acquired by an organism during its lifetime can be passed on to the next generation.
This was one of the earliest scientific theories of evolution.

12. Who is Neo-Darwinism?
Ans: Neo-Darwinism is the modern theory of evolution who combines natural selection with genetics, mutation and variation.

13. What is the modern idea of evolution?
Ans: The modern idea of evolution states that evolution occurs due to genetic variations, mutations, recombination and natural selection, resulting in gradual changes in organisms over generations.

14. What are intermediate organisms?
Ans: Intermediate organisms are those organisms that show characteristics of two different taxonomic groups and act as connecting links between them.

15. What are the similarities found in the embryos of vertebrates?
Ans: Vertebrate embryos show common features like gill slits, tail and notochord at early stages.

16. What are the reptilian and mammalian character in Duckbilled platypus?
Ans: Duck-billed platypus lays eggs like reptiles and has mammary glands like mammals.

17. What are the reptilian and bird or avian characters of Archaeopteryx?
Ans: Archaeopteryx shows reptilian characters like teeth and tail, and bird characters like feathers and wings.

18. How does the fossil of horse act as an evidence in support of organic evolution?
Ans: Horse fossils show gradual changes in size, limbs and teeth, proving evolution over time.

19. What is the germplasm theory?
Ans: Germplasm theory states that hereditary characters are transmitted only through germ cells.

20. What do you mean by interspecific and intraspecific struggles?
Ans: Interspecific struggle occurs between different species, while intraspecific struggle occurs among individuals of the same species.

21. What is variation?
Ans: Variation refers to differences in structure and characters among individuals of the same species.

22. What is continuous variation?
Ans: Continuous variation shows small gradual differences without distinct boundaries.

23. What are analogous organs?
Ans: Analogous organs are organs that perform the same function but differ in origin and internal structure.

24. What are homologous organs?
Ans: Homologous organs are organs that have the same origin and basic structure but perform different functions in different organisms.

25. Mention the law of use and disuse in relation to organic evolution.
Ans: According to the law of use and disuse, frequently used organs become stronger and well developed, while unused organs gradually degenerate and become vestigial.

26. What is chemogeny?
Ans: Chemogeny is the process by which simple organic compounds were formed from inorganic substances on the primitive Earth.

27. Define life.
Ans: Life is a condition characterized by metabolism, growth, reproduction and response to stimuli.

28. What are naked genes?
Ans: Naked genes are free nucleic acid molecules that exist without any protective covering or cell membrane.

29. What are proteinoids?
Ans: Proteinoids are protein-like substances formed by heating amino acids under primitive Earth conditions.

30. What are microspheres?
Ans: Microspheres are spherical structures formed from proteinoids that show some life-like properties, such as growth and division.

4. Long-type questions and answers

1. Discuss the basis structures of heart in different groups of vertebrate animals as evidence of organic evolution.
Ans: The structure of the heart in vertebrates shows gradual evolutionary advancement.
In fishes, the heart is two-chambered and carries only deoxygenated blood. Amphibians have a three-chambered heart, where oxygenated and deoxygenated blood partially mix. Reptiles also possess a three-chambered heart, but the ventricle is partially divided. Birds and mammals have a four-chambered heart, ensuring complete separation of oxygenated and deoxygenated blood. This gradual improvement in heart structure shows adaptation to different habitats and supports the concept of organic evolution.

2. How are homologous organs of plants helpful in explaining evolution?
Ans: Homologous organs in plants are those organs which have the same origin and basic structure but perform different functions. These organs arise from the same ancestral organ and later get modified to perform different functions according to environmental needs. For example, the thorn of Bougainvillea and the tendril of Cucurbita both originate from the stem. In Bougainvillea, the stem is modified into a thorn for protection, while in Cucurbita, the stem is modified into a tendril for climbing. This shows that different plant organs have evolved from a common ancestral structure. Such modifications indicate divergent evolution and strongly support the concept of organic evolution in plants.

3. How the homologous and analogous organs give evidence in favour of evolution?
Ans: Homologous organs show similarity in structure due to common ancestry, even though they perform different functions. This indicates that organisms have evolved from a common ancestor and then diversified, which supports divergent evolution. Analogous organs, on the other hand, show similarity in function but differ in origin and structure. This indicates that unrelated organisms evolved similar structures to adapt to similar environments, which supports convergent evolution both homologous and analogous organs provide strong evidence in favour of organic evolution.

4. What is missing link? Give examples of missing link from animals and plants.
Ans: A missing link is an organism that shows characteristics of two different groups of organisms and connects them evolutionarily. Such organisms represent transitional stages in the process of evolution. In animals, Archaeopteryx is a missing link between reptiles and birds as it possesses reptilian features like teeth and tail and avian features like feathers and wings. In plants, Cycas acts as a connecting link between pteridophytes and gymnosperms as it shows characteristics of both groups. Missing links clearly support the theory of organic evolution.

5. What is fossil? Explain with an example how do fossils act as evidence in favour of organic evoluation.
Ans: A fossil is the preserved remains, impressions or traces of plants and animals that lived in the geological past. Fossils are usually found embedded in rocks. Fossils provide direct evidence of evolution by showing gradual changes in structure over time. For example, fossils of horses show gradual increase in body size, reduction of toes and development of a single hoof. By studying fossils of different ages, scientists can trace the evolutionary history of organisms, proving that present-day organisms evolved from simpler ancestors.

6. Explain the main idea regarding the theories of Lamarck.
Ans: Lamarck proposed the theory of inheritance of acquired characters. His theory is based on two main principles:

Use and disuse of organs: Organs that are frequently used become well developed, while unused organs gradually degenerate.
Inheritance of acquired characters: Characters acquired during an organism’s lifetime are passed on to the next generation.

According to Lamarck, evolution occurs due to these inherited acquired characters.

7. What are the different weakness of Lamarckism?
Ans: Lamarckism explains evolution on the basis of use and disuse of organs and inheritance of acquired characters. However, the theory has several weaknesses:

There is no experimental evidence to prove that acquired characters are inherited by the next generation.
Weismann’s experiment on mice showed that even after cutting tails for many generations, the offspring were always born with tails, proving that acquired characters are not inherited.
Lamarckism ignores the role of genes and chromosomes, which are now known to control heredity.
The theory fails to explain the appearance of new characters suddenly.
Due to these scientific limitations, Lamarckism is not accepted in modern biology.

8. Write down the name of the book where charles Darwin published his theory. What do you mean by over prodigality of production?
Ans: Charles Darwin published his theory of evolution in the famous book “On the Origin of Species by Means of Natural Selection”, which was published in 1859. In this book, Darwin explained how new species are formed through the process of evolution. Over-prodigality of production means that all living organisms have the natural tendency to produce a large number of offspring at a time. However, the environment has limited food, space, and shelter, so all the offspring cannot survive. As a result, there is competition among organisms for survival. This excessive production of offspring ultimately leads to struggle for existence, which plays an important role in natural selection.

9. State in brief how the name HMS Beagle is associated with Darwin’s theory. What do you mean by heredity and origin species?
Ans: Darwin travelled around the world from 1831 to 1836 on a ship called HMS Beagle. During this voyage, he carefully observed plants and animals from different regions. His study of finches of the Galapagos Islands showed how species adapt to different environments. These observations formed the basis of Darwin’s theory of evolution. Heredity is the process by which characters are transmitted from parents to offspring. Origin of species refers to the formation of new species from pre-existing ones through evolutionary changes over long periods of time.

10. What is the relation betwen evolution and adaption?
Ans: Adaptation is the ability of an organism to adjust itself to its environment in order to survive. These adaptations may be structural, physiological or behavioural in nature. Organisms possessing favourable adaptations are able to survive and reproduce more successfully than others. When such favourable adaptations are passed from one generation to the next, they gradually accumulate over a long period of time. This accumulation of adaptations leads to permanent changes in the population, resulting in evolution. Therefore, adaptation plays a very important role in evolution and can be considered one of the driving forces of organic evolution.

11. Briefly discuss about the ideas of Lamarck and Darwin regarding the evaluation of long necked giraffes.
Ans: According to Lamarck, the ancestors of giraffes had short necks. Due to scarcity of food near the ground, giraffes continuously stretched their necks to reach leaves of tall trees. As a result of continuous use, the neck became longer during their lifetime. Lamarck believed that this acquired character was inherited by the next generation. Over many generations, giraffes developed long necks.
According to Darwin, giraffes showed natural variations in neck length. Some giraffes had slightly longer necks than others. During struggle for existence, giraffes with longer necks could reach food more easily and survived better. These giraffes reproduced more and passed their favourable characters to offspring. Over time, natural selection resulted in the evolution of long-necked giraffes.

12. What are the difference between Lamarckism and Darwinism?
Ans: Lamarckism explains evolution on the basis of use and disuse of organs and inheritance of acquired characters. According to Lamarck, changes acquired during an organism’s lifetime are passed to offspring. He did not emphasize struggle for existence or variation. Darwinism explains evolution on the basis of natural selection acting on pre-existing variations. Darwin emphasized struggle for existence, variation and survival of the fittest but did not explain the origin of variation. Thus, both theories differ in their basic principles and explanations of evolution.

13. What do you understand by Neo-Darwinism? Explain?
Ans: Neo-Darwinism, also known as the modern synthetic theory of evolution, is an improved form of Darwin’s theory. It combines Darwin’s concept of natural selection with modern genetics. According to Neo-Darwinism, evolution occurs due to genetic variations produced by mutation and recombination. These variations are inherited through genes. Natural selection acts on these variations, favouring the survival of individuals with beneficial traits. Over a long period of time, accumulation of such variations leads to the formation of new species.