Q.1 What is the primary unit of heredity in humans?
Chromosome
Gene
Allele
DNA
Explanation - Genes are the basic units of heredity, coding for proteins that determine traits.
Correct answer is: Gene
Q.2 Which type of genetic variation results from the substitution of a single nucleotide?
Insertion
Deletion
Point mutation
Duplication
Explanation - A point mutation is a change in a single nucleotide base in the DNA sequence.
Correct answer is: Point mutation
Q.3 Hardy-Weinberg equilibrium assumes all of the following EXCEPT:
No mutation
Random mating
Small population
No natural selection
Explanation - Hardy-Weinberg equilibrium assumes a large population; small populations experience genetic drift.
Correct answer is: Small population
Q.4 Which of the following is NOT a factor that affects allele frequency in populations?
Genetic drift
Gene flow
Mutation
Photosynthesis
Explanation - Photosynthesis is a biological process, not a mechanism affecting allele frequency.
Correct answer is: Photosynthesis
Q.5 Which type of selection favors the average phenotype over extremes?
Directional selection
Stabilizing selection
Disruptive selection
Sexual selection
Explanation - Stabilizing selection reduces variation by favoring intermediate traits.
Correct answer is: Stabilizing selection
Q.6 What term describes a population's total genetic makeup?
Genotype
Gene pool
Phenotype
Karyotype
Explanation - The gene pool represents all alleles in a population at a given time.
Correct answer is: Gene pool
Q.7 Which type of mutation is more likely to be passed on to offspring?
Somatic mutation
Germline mutation
Neutral mutation
Silent mutation
Explanation - Germline mutations occur in reproductive cells and can be inherited.
Correct answer is: Germline mutation
Q.8 The founder effect is a type of:
Mutation
Gene flow
Genetic drift
Natural selection
Explanation - Founder effect occurs when a small group of individuals establishes a new population, affecting allele frequencies by chance.
Correct answer is: Genetic drift
Q.9 Which of the following is an example of co-dominance?
AB blood group
Type O blood
Blue eye color
Cystic fibrosis allele
Explanation - In AB blood type, both A and B alleles are fully expressed, showing co-dominance.
Correct answer is: AB blood group
Q.10 Which concept explains the maintenance of genetic variation through heterozygote advantage?
Stabilizing selection
Balancing selection
Directional selection
Disruptive selection
Explanation - Balancing selection maintains multiple alleles because heterozygotes have a selective advantage.
Correct answer is: Balancing selection
Q.11 Which population concept describes the proportion of individuals carrying a particular allele?
Allele frequency
Gene pool
Genotype
Phenotype
Explanation - Allele frequency measures how common an allele is in a population.
Correct answer is: Allele frequency
Q.12 Which of the following is an example of a polygenic trait?
Blood type
Height
Widow's peak
Tongue rolling
Explanation - Height is influenced by multiple genes, making it polygenic.
Correct answer is: Height
Q.13 Which of these can introduce new alleles into a population?
Mutation
Genetic drift
Inbreeding
Random mating
Explanation - Mutations are the ultimate source of new alleles in a population.
Correct answer is: Mutation
Q.14 In population genetics, 'p' typically represents:
Frequency of the dominant allele
Frequency of the recessive allele
Population size
Phenotype frequency
Explanation - In the Hardy-Weinberg formula, 'p' denotes the frequency of the dominant allele.
Correct answer is: Frequency of the dominant allele
Q.15 Which type of natural selection favors individuals at both extremes of a trait?
Directional selection
Stabilizing selection
Disruptive selection
Sexual selection
Explanation - Disruptive selection favors extreme phenotypes over intermediates.
Correct answer is: Disruptive selection
Q.16 Which type of allele is expressed only when homozygous?
Dominant
Recessive
Co-dominant
Incomplete dominant
Explanation - Recessive alleles are masked by dominant alleles unless homozygous.
Correct answer is: Recessive
Q.17 Which is NOT a consequence of inbreeding in small populations?
Increased homozygosity
Reduced genetic diversity
Increased heterozygosity
Higher risk of genetic disorders
Explanation - Inbreeding reduces heterozygosity and can increase genetic disorders.
Correct answer is: Increased heterozygosity
Q.18 Which term refers to the process of random changes in allele frequency due to chance?
Genetic drift
Mutation
Gene flow
Natural selection
Explanation - Genetic drift occurs by chance, especially in small populations.
Correct answer is: Genetic drift
Q.19 Which of the following best describes gene flow?
Movement of alleles between populations
Mutation within a population
Selection for advantageous traits
Random genetic changes
Explanation - Gene flow is the transfer of alleles from one population to another.
Correct answer is: Movement of alleles between populations
Q.20 Which of the following is a measure of genetic variation in a population?
Heterozygosity
Allele dominance
Mutation rate
Population size
Explanation - Heterozygosity measures the proportion of individuals with different alleles at a locus.
Correct answer is: Heterozygosity
Q.21 Sickle cell trait provides an example of:
Directional selection
Balancing selection
Disruptive selection
Stabilizing selection
Explanation - Heterozygotes for sickle cell allele have a malaria resistance advantage, maintaining both alleles.
Correct answer is: Balancing selection
Q.22 Which of these is a chromosomal mutation?
Insertion
Duplication
Translocation
Point mutation
Explanation - Translocation involves segments of chromosomes being rearranged, unlike single-base mutations.
Correct answer is: Translocation
Q.23 Which evolutionary force tends to reduce genetic differences between populations?
Genetic drift
Mutation
Gene flow
Natural selection
Explanation - Gene flow mixes alleles between populations, reducing differences.
Correct answer is: Gene flow
Q.24 The study of allele frequency changes over time in populations is called:
Genomics
Population genetics
Molecular biology
Cytogenetics
Explanation - Population genetics focuses on how genetic composition changes in populations over time.
Correct answer is: Population genetics