Heredity and Evolution MCQ
1. Exchange of genetic material takes place in
(a) vegetative reproduction
(b) asexual reproduction
(c) sexual reproduction
(d) budding
Ans. (c) Sexual reproduction
Explanation: All other options show asexual reproduction in which genes are contributes by a single parent. In sexual reproduction, genes are contributed by two parents and hence exchange of genetic material take place.
2. Two pink coloured flowers on crossing resulted in 1 red, 2 pink and 1 white flower progeny. The nature of the cross will be
(a) double fertilization
(b) self-pollination
(c) cross fertilization
(d) no fertilization
Ans. (c) Cross fertilization
Explanation: The term ‘cross’ in the question indicated towards cross fertilization.
3. A cross between a tall plant (TT) and short pea plant (tt) resulted in progeny that were all tall plants because
(a) tallness is the dominant trait
(b) shortness is the dominant trait
(c) tallness is the recessive trait
(d) height of pea plant is not governed by gene ‘T’ or ‘t’
Ans. (a) tallness is the dominant trait
Explanation: In monohybrid cross, dominant character is the only character expressed in the first generation of progeny.
4. Which of the following statement is incorrect?
(a) For every hormone there is a gene.
(b) For every protein there is a gene.
(c) For production of every enzyme there is a gene.
(d) For every molecule of fat there is a gene
Ans. (b) For every protein there is a gene.
Explanation: Hormones and enzymes are made up of protein. Hence, other are correct statements.
5. If a round, green seeded pea plant (RR yy) is crossed with wrinkled, yellow seeded (a) round and yellow
(b) round and green
(c) wrinkled and green
(d) wrinkled and yellow
Ans. (a) round and yellow
Explanation: In this case, roundness and yellow colour are dominant characters. These will be fully expressed in F1 generation.
6. In human males all the chromosomes are paired perfectly except one. This/ these unpaired chromosomes is/are
(i) large chromosome
(ii) small chromosome
(iii) Y-chromosome
(iv) X-chromosome
(a) (i) and (ii)
(b) (iii) only
(c) (iii) and (iv)
(d) (ii) and (iv)
Ans. (c) (iii) and (iv)
Explanation: The last pair of chromosomes in a human male contains X and Y chromosomes.
7. The maleness of a child is determined by
(a) the X chromosome in the zygote
(b) the Y chromosome in zygote
(c) the cytoplasm of germ cell which determines the sex
(d) sex is determined by chance
Ans. (b) the Y chromosome in zygote
Explanation: If a sperm with Y chromosome fertilizes the egg, the resulting zygote would develop into a male child.
8. A zygote which has an X-chromosome inherited from the father will develop into a
(a) boy
(b) girl
(c) X- chromosome does not determine the sex of a child
(d) either boy or girl
Ans. (b) Girl
Explanation: If a sperm with X chromosome fertilizes the egg, the resulting zygote would develop into a girl child.
9. Select the incorrect statement
(a) Frequency of certain genes in a population change over several generations resulting in evolution
(b) Reduction in weight of the organism due to starvation is genetically controlled
(c) Low weight parents can have heavy weight progeny
(d) Traits which are not inherited over generations do not cause evolution
Ans. (b) Reduction in weight of the organism due to starvation is genetically controlled
Explanation: Reduction in weight due to starvation is a temporary change. This change is removed once food becomes available in plenty.
10. New species may be formed if
(i) DNA undergoes significant changes in germ cells
(ii) chromosome number changes in the gamete
(iii) there is no change in the genetic material
(iv) mating does not take place
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii), (iii) and (iv)
(d) (i), (ii) and (iii)
Ans. (a) (i) and (ii)
Explanation: If there is no change in the genetic material, then no evolution would take place. Sexual reproduction cannot take place without mating. Hence, statements (iii) and (iv) are incorrect.
11. Two pea plants one with round green seeds (RRyy) and another with wrinkled yellow (rrYY) seeds produce F1 progeny that have round, yellow (RrYy) seeds. When F1 plants are selfed, the F2 progeny will have new combination of characters. Choose the new combination from the following
(i) Round, yellow
(ii) Round, green
(iii) Wrinkled, yellow
(iv) Wrinkled, green
(a) (i) and (ii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (i) and (iii)
Ans. (c) (ii) and (iii)
12. A basket of vegetables contains carrot, potato, radish and tomato. Which of them represent the correct homologous structures?
(a) Carrot and potato
(b) Carrot and tomato
(c) Radish and carrot
(d) Radish and potato
Ans. (c) Radish and carrot
Explanation: Radish and carrot are modified tap roots. Their function is storage of food. Hence, they are homologous structures.
