MCQs on Natural Selection Neo-Darwinism Mechanism of evolution

By Dr. M.J.Sundar Ram (Professor of Zoology (Rtd.) Vijaya College, Bangalore)

1. According to Darwin, which is the fittest organism?

1) Organism which is very strong 2) Organism which leaves a large no. of offspring

3) Organism which is very aggressive

4) Organism which is very cruel.

2. Which of the following points which Darwin could not explain:

a. Competition

b. arrival of the fittest

c) overproduction

d) survival of the fittest

3. Darwin explained his theory of Natural Selection on 4 points. Out of them, which one was a weak point: a. Variations b. Survival of the fittest c. Struggle for existence d. Overproduction

4. Which statement explains Neo-Darwinism:

1) Without mutation there can be no evolution 2) Natural force is the only and supreme force in evolution 3) Evolution occurs because there is struggle for existence leading to the survival of the fittest. 4) Natural selection, Mendelism and Mutations work in tandem for evolution.

5. Which of the following is also known as Sewall Wright effect: a. Natural Selection b. Genetic drift c. Mutation d. Recapitulation theory

6. Which of the following factors plays a prominent role in evolution: a. Overproduction b. Phenotypic variation c. Genotypic variation d. Use and disuse of organs

7. According to Darwin, evolution:

a. Is a sudden and discontinuous process

b. Is a slow but discontinuous process

c. Is a slow, gradual and continuous process

d. Is a sudden but continuous process

8. Natural selection can operate only when there are:

a. Too many offspring

b. too little members in the population

c. Competitions

d. variations among organisms

9. Which of the examples demonstrates that natural selection can act only if variations are present:

a. Lengthening of neck of giraffe

b. DDT resistance in mosquitos

c. Limbless condition of snakes

d. Ontogeny recapitulates phylogeny

11. The unit of evolution is:

a. Population

b. individual

c. family

d. gene

11. Choose the elementary forces of evolution: a) Selection, migration, isolation b) Mutation, isolation, genetic drift c) Migration, isolation, mutation d) Mutation, genetic drift, selection

12. If there is no fluctuation in the frequencies of genes in the gene pool of a population, the population is said to be:

a. Degenerating

b. evolving

c. in equilibrium

d. changing

13. If a group of organisms migrate to different environments and get established there, it is known as:

a. Adaptive radiation

b. Convergent evolution

c. parallel evolution

d. Organic evolution

14. If some fittest members of a population are killed before they pass on their genes to the next generation it is known as:

a. Natural selection

b. Artificial selection

c. Convergent evolution

d. Sewall Wright effect

15. Which of the following plays a prominent role in evolution by providing variations: a. Mitotic cell division b. parthenogenesis c. asexual reproduction d. sexual reproduction

16. Name the scientist who conducted experiments on the peppered moth Biston betularia:

a. Kettlewell

b. Tschermak

c. Sewall Wright

d. Weismann

17. Which of the following is not a source of variation:

a. Meiosis

b. Sexual reproduction

c. Mitosis

d. Mutation

18. Column I contains names of evolutionists and column II their contributions. Match them:

1. Evolutionists 2. Their contributions

1. Weismann p. inheritance of acquired characters

1. Darwin q. continuation of germplasm

1. Lamarck r. mutation

1. De Vries s. natural selection

•a. 1-p, 2-q, 3-r, 4-s •b. 1-q, 2-s, 3-p, 4-r •c. 1-r, 2-p, 3-q, 4-s •d. 1-s, 2-p, 3-q, 4-r

19. De Vries believed that evolution occurs in a single step by large mutation. He called it as:

•a. Polyploidy

•b. Non-disjunction

•c. Saltation

•d. Crossing over

•

21. Darwin might have made even greater advances in his theory if he had:

a. understood the work of Gregor Mendel.

b. read the works of Malthus.

c. read of the work of Weismann.

d. understood the theories of Jean Baptiste de Lamarck.

21. When populations with separate ancestors adapt in similar ways to similar environ-mental constraints, it is referred to as:

•a. biogeography.

•b. coevolution.

•c. convergent evolution.

•d. homologous evolution. •

. 22. The theory of Pangenesis was proposed by:

• a. Weismann

• b. De Vries

• c. Lamarck

• d. Darwin

23. Darwin’s theory does not include:

a. evolution through inheritance

b. Natural selection

c. survival of the fittest

d. struggle for existence.

24. According to Malthus:

a. food production and population increase proportionately over years b. food production increases while population decreases over the years c. food production remains the same but population alone increases steadily d. food production increases by arithmetic ratio & population increases by geometrical ratio.

25. Natural selection can operate only in the presence of:

a. genetic drift

b. survival of the fittest

c. isolation

d. variations

26. Darwin believed that: a. Evolution is sudden and discontinuous b. Evolution is a slow and steady process c. Evolution occurs as a result of mutations d. Evolution is slow, gradual and continuous.

27. DDT resistance in mosquitoes shows that:

•a. Mutation and natural selection work together to select the fittest

•b. Mutation is a very important factor in selecting the fittest

•c. Natural selection is the supreme force in selecting the fittest

•d. Mutation and Mendelism are very important in selecting the fittest.

28. Industrial melanism has shown that:

a. Mutation is always beneficial to an organism

b. Mutation is always harmful to an organism

c. Favourable mutation is preserved by the environment

d. Mutation is predetermined by an organism.

•29. Select the elemental forces of evolution: •a. Mutation, gene pool, migration •b. Genetic drift, mutation, selection •c. Selection, non-disjunction, environment •d. polyploidy, phenotype, segregation.

30. Panmictic population means: a. a very large population b. population with variations c. freely interbreeding members d. members are all sterile.

31. Gene pool means: a. genes contributed by the male members of a population b. genes collected in a population and kept in cold storage c. genes contributed by the female members of a population d. genes contributed by all adult members of a population.

32. Hardy Weinberg equilibrium means: a. the population is well balanced with equal no. of males and

females

b. the number of individuals in the population remain always constant

c. the members contribute a large number of offspring to the nest generation

d. the elementary forces of evolution do not operate on the gene pool.

33. This is not genetic drift:

a. it is a matter of probability

b. it is also known as Sewall Right Effect

c. it is also known as non-adaptive evolution

d. it is also known as convergent evolution

34. Which of the following statements is true:

•a. Gene flow and genetic drift both decrease variations in the population

•b. Gene flow increases variations but genetic drift decreases variations

•c. Gene flow decreases variations but genetic drift increases variations

•d. Gene flow and genetic drift both increase variations in the population.

35. The elimination of short-necked giraffe & preservation of normal and long-necked giraffe is an example of:

A) disruptive selection

B) stabilizing selection

C) directional selection

D) random selection

36. According to Darwin, every organ of the body sends a miniature unit to the germ cells which later develop into that particular organ in the zygote. This unit is called: 1) germplasm 2) gemmules 3) somatoplasm 4) mutant

37. Organisms differ from one another because of:

1) phenotypic variations

2) pangenes

3) genotypic variations

4) inheritance of acquired traits

38. In some cases fittest organisms are destroyed and unfit survive. This is due to:

1) survival of the fittest

2) genetic drift

3) isolation

4) migration

39. Read the two statements given below: Statement A: Genetic drift reduces variations. Statement B: gene flow increases variations. Statement A is wrong but B is correct Statements A and B are correct Statement A correct, B is wrong Statements A and B are correct

40. The figure below shows selection in which members with extreme characters survive but average members perish. Identify the type of selection.

a) Stabilising selection b) directional selection c) Disruptive selection d) Destructive selection