Mechanism: variation, mutation, recombination, natural selection
- Which one of the following is NOT an advantage of inbreeding? Answer: 1. It decreases the productivity of inbred population, after continuous inbreeding. Key idea: Inbreeding increases homozygosity. It... 1
- Given below are two statements:Statement I: RNA mutates at a faster rate.Statement II: Viruses having RNA genome and shorter life span mutate and evolve faster.In the light of the above statements, choose the correct answer from the options given bel… Answer: 2. Both Statement I and Statement II are true. Key idea: RNA genomes mutate faster than DNA genomes. Statement I is true: RNA is les... 1
- Natural selection where more individuals acquire specific character value other than the mean character value, leads to : Answer: 3. Directional change Key idea: When more individuals move to one extreme of the trait, away from the mean, the curve shifts one way... 1
- Which of the following refer to correct example(s) of organisms which have evolved due to changes in environment brought about by anthropogenic action ?(a) Darwin's Finches of Galapagos islands.(b) Herbicide resistant weeds.(c) Drug resistant eukaryo… Answer: 3. (b), (c) and (d) Key idea: Look for evolution driven by human-caused environmental change. (b) Herbicide-resistant weeds, (c) dru... 1
- By which method was a new breed 'Hisardale' of sheep formed by using Bikaneri ewes and Marino rams ? Answer: 3. Cross breeding Hisardale is a product of cross breeding, in which superior males of one breed are mated with superior females of... 1
- Select the incorrect statement. Answer: 3. Inbreeding selects harmful recessive genes that reduce fertility and productivity. Inbreeding increases homozygosity, helps make... 1
- According to Hugo de Vries, the mechanism of evolution is Answer: 3. Saltation Key idea: Hugo de Vries proposed mutation theory. He said evolution happens through single-step large mutations, called... 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