Genetics and Evolution
- Among the following sets of examples for divergent evolution, select the incorrect option : Answer: 4. Eye of octopus, bat and man Key idea: Divergent evolution means homologous organs (same origin) adapted to different functions. O... 1
- The similarity of bone structure in the forelimbs of many vertebrates is an example of Answer: 1. Homology Key idea: Similar bone structure in the forelimbs of different vertebrates shows a common ancestral origin, which is hom... 1
- Artificial selection to obtain cows yielding higher milk output represents : Answer: 1. directional as it pushes the mean of the character in one direction. Selecting cows for higher milk yield moves the mean of the t... 1
- Homozygous purelines in cattle can be obtained by : Answer: 4. mating of related individuals of same breed. Key idea: Inbreeding increases homozygosity. Mating of closely related individuals o... 1
- Genetic drift operates in Answer: 4. small isolated population Genetic drift is a random change in allele frequency due to chance. Its effect is strong in small isola... 1
- In Hardy-Weinberg equation, the frequency of heterozygous individual is represented by Answer: 1. 2 pq The Hardy-Weinberg equation is p² + 2pq + q² = 1 . p² and q² are the homozygous genotypes, and 2pq is the frequency of heter... 1
- The chronological order of human evolution from early to the recent is Answer: 1. Ramapithecus → Australopithecus → Homo habilis → Homo erectus Use the approximate ages given in NCERT. Ramapithecus: about 15 mil... 1
- Which of the following is the correct sequence of events in the origin of life?I. Formation of protobiontsII. Synthesis of organic monomersIII. Synthesis of organic polymersIV. Formation of DNA-based genetic systems Answer: 2. II, III, I, IV The chemical evolution order is: Synthesis of organic monomers (II). Synthesis of organic polymers (III). Formatio... 1
- Which of the following structures is homologus to the wing of a bird ? Answer: 4. Flipper of Whale Homologous organs share the same basic anatomical plan (here the forelimb bones) but may differ in function. A b... 1
- Analogous structures are a result of : Answer: 2. Convergent evolution Analogous structures have different origins but similar function because unrelated organisms face similar en... 1
- Following are the two statements regarding the origin of life :(a) The earliest organisms that appeared on the earth were non-green and presumably anaerobes.(b) The first autotrophic organisms were the chemoautotrophs that never released oxygen.Of th… Answer: 3. Both (a) and (b) are correct. Both statements are correct. Life began in an oxygen-free atmosphere, so the first cells were non-g... 1