Heredity and evolution Worksheet-11

Heredity and evolution Worksheet-11

1. If a plant heterozygous for tallness is selfed, the F₂ generation has both tall and dwarf plants in 3:1 ratio. This proves the principle of :

A. Dominance

B. Segregation

C. Independent assortment

D. Incomplete dominance

2. If an enzyme responsible for the production of phytohormone (for plant height) becomes active then that phytohormone brings phenotypic change. If the gene for that enzyme has an alteration it makes the enzyme less efficient and the amount of hormone will be less, consequently the plant will be short. This shows that

A. Traits are controlled by genes

B. Traits are controlled by hormones

C. Enzymes control characters

D. Traits get expressed by plant part

3. Which of the following given facts is correctly related to Charles Darwin?

A. He gave theory of natural selection in his book 'The Origin of Species'

B. Darwin studied the role of earthworms in soil fertility

C. Darwin's natural selection theory is based on survival of the fittest

D. All of these

4. Mendel selected garden peas as his experimental material because :

(i) Pea plants possess a number of well defined contrasting characters.

(ii) Pea plants contain unisexual flowers.

(iii) Pea plants have perfect bisexual flowers.

(iv) These are annual plants.

A. (i) & (iv)                                     B. (i) & (ii)

C. (i) & (iii)                                    D. (i),(iii)&(iv)

5. Which of the following statements is false about sex chromosomes in humans?

A. A male has one X chromosome and one Y chromosome

B. A female has two X chromosomes but no Y chromosome

C. Males have a mismatched pair of sex-chromosomes in which Y is normal sized while X is a short one

D. Males have a mismatched pair of sex-chromosomes in which Y is short one and X is normal sized

6. Genetic drift is defined as:

A. A random change in gene frequencies from one generation to the next

B. A change in an allele due to alteration in the DNA molecule

C. A change in gene frequencies due to exchange of genes between different populations

D. A product of natural selection

7. Which of the following is not an instance of evolutionary change?

A. Gene flow                                  B. Natural selection

C. Genetic drift                             D. None of these

8. The movement of new genes into a population as a result of migration or interbreeding between members of the two populations is called:

A. Genetic load                              B. Selection

C. Gene flow                                  D. Adaptation

9. Which of the following statements regarding natural selection is/are true?

A. It is a process in which members of a population inherit traits that enable them to better survive and produce offspring

B. It is based on the isolation of natural populations and selective breeding of organisms

C. It provides diversity without any adaptation

D. All of these

10. Mendel's findings remained unknown until these were rediscovered by which of the following biologists in 1900?

A. Hugo deVries                           B. Karl Correns

C. Enrich von Tshermak             D. All of these

Answer Key:

1. B
2. A
3. D
4. D
5. C
6. A
7. D
8. C
9. A
10. D