Q.1 What is the main focus of population genetics?
Study of gene expression in individuals
Study of gene frequency changes in populations
Study of protein structures
Study of cellular metabolism
Explanation - Population genetics focuses on how gene frequencies in a population change over time due to evolutionary forces like mutation, selection, migration, and genetic drift.
Correct answer is: Study of gene frequency changes in populations
Q.2 Which of the following is an example of a microevolutionary force?
Mutation
Continental drift
Formation of the universe
Plate tectonics
Explanation - Mutation introduces new alleles into a population, affecting gene frequencies, which is a microevolutionary process.
Correct answer is: Mutation
Q.3 In Hardy-Weinberg equilibrium, which condition must be met?
Small population size
No selection
Frequent migration
High mutation rate
Explanation - Hardy-Weinberg equilibrium assumes no selection, no mutation, no migration, random mating, and infinitely large population size.
Correct answer is: No selection
Q.4 Which equation represents the Hardy-Weinberg principle for allele frequencies?
p + q = 1
p^2 + 2pq + q^2 = 1
Both of the above
Neither of the above
Explanation - The allele frequencies are represented as p + q = 1 and genotype frequencies as p^2 + 2pq + q^2 = 1.
Correct answer is: Both of the above
Q.5 Genetic drift has the greatest effect in which type of population?
Large populations
Small populations
Populations at equilibrium
Species with long lifespans
Explanation - Random changes in allele frequencies due to genetic drift are more pronounced in small populations.
Correct answer is: Small populations
Q.6 Which of the following is an example of gene flow?
Migration of individuals between populations
Random mating within a population
Chromosomal mutation
Natural selection favoring an allele
Explanation - Gene flow occurs when individuals or gametes move between populations, introducing or removing alleles.
Correct answer is: Migration of individuals between populations
Q.7 Which type of selection favors extreme phenotypes?
Stabilizing selection
Directional selection
Disruptive selection
Balancing selection
Explanation - Disruptive selection favors individuals with extreme traits at both ends of a phenotypic range.
Correct answer is: Disruptive selection
Q.8 What does 'heterozygote advantage' refer to?
Homozygotes have higher fitness
Heterozygotes have higher fitness
Allele frequencies remain constant
Random mating occurs
Explanation - Heterozygote advantage occurs when individuals with two different alleles at a locus have a fitness advantage over homozygotes.
Correct answer is: Heterozygotes have higher fitness
Q.9 Which scenario can lead to a population bottleneck?
Massive natural disaster
Introduction of new alleles
Random mating
High mutation rate
Explanation - A bottleneck occurs when a population size is drastically reduced, reducing genetic variation.
Correct answer is: Massive natural disaster
Q.10 What is the founder effect?
A mutation in a large population
Loss of genetic variation when a small group colonizes a new area
Balancing selection
Stabilizing selection
Explanation - The founder effect occurs when a small population establishes a new population, carrying only a fraction of the original population's alleles.
Correct answer is: Loss of genetic variation when a small group colonizes a new area
Q.11 Which of the following best describes stabilizing selection?
Favors intermediate phenotypes
Favors extreme phenotypes
Randomly changes allele frequencies
Occurs only in small populations
Explanation - Stabilizing selection reduces variation by favoring average phenotypes over extremes.
Correct answer is: Favors intermediate phenotypes
Q.12 Which concept explains the maintenance of multiple alleles in a population?
Genetic drift
Balancing selection
Bottleneck effect
Founder effect
Explanation - Balancing selection maintains genetic diversity in a population by favoring multiple alleles.
Correct answer is: Balancing selection
Q.13 Which of the following is a measure of genetic variation within a population?
Allele frequency
Heterozygosity
Both of the above
None of the above
Explanation - Genetic variation can be measured by allele frequencies and the proportion of heterozygotes.
Correct answer is: Both of the above
Q.14 Mutation is important in evolution because it:
Increases population size
Introduces new alleles
Removes alleles from populations
Promotes random mating
Explanation - Mutation creates new genetic variants, providing raw material for evolution.
Correct answer is: Introduces new alleles
Q.15 Which of the following is NOT an assumption of the Hardy-Weinberg equilibrium?
Random mating
No selection
Finite population size
No migration
Explanation - Hardy-Weinberg assumes infinitely large populations to avoid genetic drift.
Correct answer is: Finite population size
Q.16 Which term refers to the random loss of alleles in a population?
Natural selection
Genetic drift
Gene flow
Mutation
Explanation - Genetic drift causes random fluctuations in allele frequencies, especially in small populations.
Correct answer is: Genetic drift
Q.17 What is the main effect of migration on a population?
Reduces genetic diversity within populations
Increases genetic diversity between populations
Changes allele frequencies and homogenizes populations
Causes random mating
Explanation - Migration introduces or removes alleles, reducing differences between populations.
Correct answer is: Changes allele frequencies and homogenizes populations
Q.18 Directional selection often results in:
Increased frequency of one extreme phenotype
Increased heterozygosity
Equal fitness of all genotypes
Loss of extreme phenotypes
Explanation - Directional selection favors one extreme, shifting the population mean.
Correct answer is: Increased frequency of one extreme phenotype
Q.19 Which statement about allele frequencies is TRUE?
They always remain constant
They can change due to mutation, selection, or drift
They are unrelated to population size
They determine the physical traits of a single individual only
Explanation - Allele frequencies fluctuate due to evolutionary forces in populations over generations.
Correct answer is: They can change due to mutation, selection, or drift
Q.20 Which of the following reduces genetic variation within a population?
Balancing selection
Bottleneck effect
Gene flow
Mutation
Explanation - A bottleneck drastically reduces population size, reducing genetic variation.
Correct answer is: Bottleneck effect
Q.21 The sum of allele frequencies in a population is always:
Greater than 1
Less than 1
Equal to 1
Variable depending on selection
Explanation - By definition, the total frequency of all alleles at a locus is 1.
Correct answer is: Equal to 1
Q.22 Which of the following is a consequence of inbreeding?
Increased heterozygosity
Increased homozygosity
Introduction of new alleles
Random mating
Explanation - Inbreeding increases the probability that offspring inherit identical alleles from both parents, increasing homozygosity.
Correct answer is: Increased homozygosity
Q.23 Which type of natural selection maintains genetic diversity by favoring heterozygotes?
Directional selection
Stabilizing selection
Disruptive selection
Balancing selection
Explanation - Balancing selection maintains multiple alleles, often by favoring heterozygotes.
Correct answer is: Balancing selection
Q.24 Effective population size refers to:
Total number of individuals
Number of breeding individuals contributing to the next generation
Population size after a bottleneck
Number of alleles in a population
Explanation - Effective population size determines the impact of genetic drift and inbreeding on allele frequencies.
Correct answer is: Number of breeding individuals contributing to the next generation
Q.25 Which force can introduce entirely new alleles into a population?
Genetic drift
Mutation
Selection
Gene flow
Explanation - Mutation generates novel alleles, providing raw material for evolution.
Correct answer is: Mutation