The material on which Hugo de Vries experimented to explain the mechanism of evolution thus pioneering the theory of mutations was:
[A] Fruit fly
[B] China rose
[C] Garden pea
[D] Evening primrose
Hugo de Vries gave his mutation theory on organic evolution while working on:
[A] Althea rosea
[B] Pisum sativum
[C] Oenothera lamarckiana
[D] Drosophila melanogaster
For natural selection the important factor is:
[D] Special creation
In which condition does the gene ratio remain constant for any species?
[B] Gene flow
[C] Sexual selection
[D] Random mating
Initiating force of evolution is:
[D] Natural selection
The raw material for organic evolution is:
[A] Asexual reproduction
[C] Nutritive substances
[D] Effect of hormones
Lederberg replica experiment explains:
[A] Mutation theory
[B] Darwin’s theory
[C] Lamarck’s theory
[D] None of these
Some bacteria are able to grow in streptomycin containing medium due to:
[A] Genetic drift
[B] Natural selection
[C] Induced mutation
[D] Reproductive isolation
Sum of all the genes in a population is called:
[B] Gene pool
[D] Gene bank
At a particular locus, frequency of ‘A’ allele is 6 and that of ‘a’ is What would be the frequency of heterozygotes in a random mating population at equilibrium?
Genetic drift operates in:
[A] Large isolated population
[B] Small isolated population
[C] Fast reproductive population
[D] Slow reproductive population
Match the following concepts of evolution in List-I with List-II and select the correct answer using the codes given below the lists:
(A) Mutation () Changes in population’s allele frequencies due to chance alone
(B) Gene flow () Differences in survival and reproduction among variant individuals
(C) Natural selection () Immigration, emigration change allele frequencies
(D) Genetic drift () Source of new alleles
[A] A:1, B:2, C:3, D:4
[B] A:4, B:2, C:3, D:1
[C] A:3, B:1,C:4,D:2
[D] A:4, B:3, C:2, D:1
Which of the following concepts is known as the Sewall Wright effect?
[A] Genetic drift
[C] Gene pool
[D] Gene flow
Which of the following would stop evolution by A barring the occurrence of the natural selection?
[A] If humans became extinct because of a disease or epidemic.
[B] If ozone depletion led to increased ultraviolet radiation which caused many new mutations.
[C] If a thermonuclear war killed most living organisms and changed the environment drastically.
[D] If genetic recombination, sexual reproduction and mutation stopped so that all offspring of all organisms were exact copies of their parents.
Directional selection _____.
[A] works against adaptive traits
[B] favours intermediate forms of a trait
[C] eliminates uncommon forms of alleles
[D] shifts allele frequencies in a steady, consistent direction