Evolution

34 solved questions from Class 12 Biology, each with the full working. Tap any question to see the step-by-step solution.

• 1 What is the primary topic or theoretical principle explored in 'Evolution' (Class 12 BIOLOGY)? medium MCQ Chapter Core Principle
• 2 Which key mechanism or analytical rule is highlighted in 'Evolution'? medium MCQ Key Analytical Mechanism
• 3 What is the primary topic or principle explained in 'Evolution' (Class 12 Biology)? medium MCQ Chapter Core Concept
• 4 Which key observation or fact is central to understanding 'Evolution'? medium MCQ Key Fact & Mechanism
• 5 Why is the study of 'Evolution' important for students of Class 12? medium MCQ Learning Significance
• 6 What is a common application or real-world example related to 'Evolution'? medium MCQ Real World Application
• 7 What key takeaway should students retain after completing 'Evolution'? medium MCQ Chapter Summary & Takeaway
• 8 Using the principle of parsimony, construct the most likely phylogenetic tree for the following four primates: Homo sapiens, Pan troglodytes, Gorilla gorilla, Pongo abelii, and explain your reasoning. hard 4 marks Parsimony in phylogeny
• 9 Describe how a mutation can lead to antibiotic resistance in bacteria, giving a specific example of a mutation that confers resistance. medium 3 marks Mutation as raw material for evolution
• 10 After a population of 10,000 individuals splits into two equal subpopulations of 5,000 each, the allele frequency of allele A is 0.1 in one subpopulation and 0.9 in the other after 1,000 generations. Calculate the fixation index F_ST between the two subpopulations. hard 4 marks Fixation index F_ST
• 11 Which evolutionary process can lead to a reduction in genetic diversity in a small population? easy MCQ 2 marks Reduction of diversity by drift
• 12 In a population of 50 individuals, the initial heterozygosity (H₀) is 0.6. Assuming random genetic drift and an effective population size (Nₑ) of 25, calculate the expected heterozygosity after 5 generations using the formula Hₜ = H₀ \times \left(1 - \frac{1}{2Nₑ}\right)^{t}. medium 2 marks Genetic drift and heterozygosity
• 13 Given the following binary character matrix for five plant species, use the principle of maximum parsimony to infer the most parsimonious cladogram. Characters: C₁ (flower colour), C₂ (leaf arrangement), C₃ (seed type). Data: Species A: 0 0 1, Species B: 0 1 1, Species C: 1 0 0, Species D: 1 1 0, Species E: 0 0 0. Explain each step and give the final tree. hard 4 marks Maximum parsimony phylogeny
• 14 Which of the following provides the most direct evidence for evolution in a population over a short period of time? easy MCQ 1 mark Direct evidence of evolution
• 15 Two subpopulations of a beetle species each contain 2000 individuals. In subpopulation X the frequency of allele a is 0.2, and in subpopulation Y it is 0.7. Calculate the fixation index F_ST using the formula F_ST = (H_T - H_S)/H_T, where H_T = 2p̄q̄ is the total expected heterozygosity (with p̄ the mean allele frequency across subpopulations) and H_S is the average heterozygosity within subpopulations (average of 2p_i q_i for each subpopulation). hard 3 marks Genetic differentiation (F_ST)
• 16 Explain how a mutation can lead to antibiotic resistance in bacteria, providing a specific example of a mutation that confers resistance. hard 4 marks Mutation as source of adaptive change
• 17 Two subpopulations of a plant species, each with 4000 individuals, have allele L frequencies of 0.30 and 0.70 respectively. Calculate the fixation index F_ST between them using F_ST=(H_T-H_S)/H_T, where H_T=2pq and H_S=(2p_1q_1+2p_2q_2)/2. hard 3 marks Population genetics fixation index
• 18 Which of the following is the best direct evidence for recent evolution in a population? easy MCQ 1 mark Recent evolution evidence
• 19 A diploid population of 100 individuals has allele A at frequency p = 0.4. Assuming random mating and Hardy–Weinberg equilibrium, what is the expected heterozygosity in this population? medium 2 marks Hardy–Weinberg heterozygosity
• 20 In a diploid population of 200 individuals, the initial heterozygosity H₀ is 0.75. Assuming an effective population size Nₑ of 45 and random genetic drift, calculate the expected heterozygosity after 10 generations using the formula H_t = H₀(1 - 1/(2Nₑ))^t. medium 2 marks heterozygosity loss due to drift
• 21 Two subpopulations of a marine algae species each contain 1500 individuals. In subpopulation 1 the allele A frequency is 0.6, while in subpopulation 2 it is 0.2. Compute the fixation index F_ST between these subpopulations using F_ST=(H_T-H_S)/H_T, where H_T=2pq and H_S=(2p_1q_1+2p_2q_2)/2. hard 4 marks fixation index calculation
• 22 Describe how a point mutation in the gyrA gene can lead to antibiotic resistance in Escherichia coli, giving a specific example of the mutation and the antibiotic it confers resistance to. hard 5 marks mutation conferring antibiotic resistance
• 23 Which of the following provides the most direct evidence for recent evolution in a natural population? easy MCQ 1 mark Direct evidence of recent evolution
• 24 Given the following binary character matrix for five insect species, use the principle of maximum parsimony to infer the most parsimonious cladogram. Characters: C₁ (wing presence), C₂ (metamorphosis type), C₃ (mouthpart type). Data: Species A: 1 0 1, Species B: 1 1 1, Species C: 0 0 0, Species D: 0 1 0, Species E: 1 0 0. Explain each step and give the final tree. hard 5 marks Maximum parsimony phylogeny
• 25 Describe how a point mutation in the rpoB gene of Mycobacterium tuberculosis can lead to resistance against the antibiotic rifampicin. Mention a specific mutation and its effect on the drug target. medium 3 marks Mutation‑driven antibiotic resistance
• 26 In a diploid population of 150 individuals the initial heterozygosity H₀ is 0.68. The effective population size Nₑ is 30. Assuming random genetic drift, what is the expected heterozygosity after 8 generations? Use H_t = H₀(1 - 1/(2Nₑ))^t. medium 3 marks Effect of genetic drift on heterozygosity
• 27 Explain how antibiotic resistance in bacteria can be an example of rapid evolution. Discuss the roles of selective pressure, mutation, and horizontal gene transfer, using the example of the β‑lactamase gene in ‘Escherichia coli’ conferring resistance to ampicillin. hard 4 marks Evolutionary mechanisms
• 28 Two subpopulations of a marine fish species each contain 600 individuals. Subpopulation 1 has allele frequency p_1=0.4 and Subpopulation 2 has p_2=0.9. Compute the fixation index F_ST between these subpopulations. Use F_ST=(H_T-H_S)/H_T where H_T=2pq and H_S=(2p_1q_1+2p_2q_2)/2. medium 2 marks Population genetics
• 29 A diploid population of 200 individuals has an effective population size of 50 and an initial heterozygosity of 0.80. Assuming random genetic drift, what is the expected heterozygosity after 3 generations? Use H_t=H_0(1-1/2N_e)^t. easy 1 mark Random genetic drift
• 30 Which point mutation in the rpoB gene of Mycobacterium tuberculosis confers resistance to rifampicin? easy MCQ 1 mark Antibiotic resistance via point mutation
• 31 Explain how natural selection can lead to the evolution of larger body size in Arctic mammals over successive generations. medium 3 marks Natural selection and adaptation
• 32 Using the principle of maximum parsimony, construct the most parsimonious phylogenetic tree for the following species based on binary characters: Species A: 0 0 1, Species B: 0 1 1, Species C: 1 0 0, Species D: 1 1 0, Species E: 0 0 0. Explain each step and give the final tree. medium 4 marks Phylogenetic inference via parsimony
• 33 Describe how a point mutation in the gyrA gene of Escherichia coli confers resistance to ciprofloxacin. Mention a specific mutation and its effect on the drug target. medium 3 marks Antibiotic resistance via point mutation
• 34 Which of the following evolutionary processes directly reduces genetic variation within a population? easy MCQ 1 mark Genetic drift effect on diversity