NEET Biology Evolution MCQs Set 14

Answer: (b) Weismann

Explanation:
1. August Weismann proposed the theory of continuity of germplasm. It says that the germ cells are separate from body cells.

Teacher's Note:
1. It disproved inheritance of acquired characters.
2. Weismann and germplasm go together.

Answer: (b) Lamarck

Explanation:
1. Lamarck proposed the theory of inheritance of acquired characters, along with use and disuse of organs.

Teacher's Note:
1. Darwin proposed natural selection.
2. Link the name with the theory.

Answer: (d) Darwin

Explanation:
1. Charles Darwin wrote On the Origin of Species in 1859.

Teacher's Note:
1. Wallace independently thought of natural selection.
2. Darwin wrote the book.

Answer: (c) O2

Explanation:
1. Free oxygen was absent in the primitive atmosphere, which had NH3, H2, CH4 and water vapour.

Teacher's Note:
1. Oxygen came later by photosynthesis.
2. The early atmosphere was reducing.

Answer: (b) chemoheterotrophs

Explanation:
1. The first organisms were chemoheterotrophs (they used organic molecules) and anaerobic.

Teacher's Note:
1. Autotrophs and eukaryotes came later.
2. First life lived on available organic matter.

Answer: (d) Lamarckism was wrong in inheritance of acquired characters

Explanation:
1. Weismann cut the tails of mice for many generations, but newborn mice always had tails. This disproved Lamarck's inheritance of acquired characters.

Teacher's Note:
1. Only germ cell changes are inherited.
2. Body changes are not inherited.

Answer: (c) gene frequency from one generation to next

Explanation:
1. Genetic drift is a random change in allele frequency from one generation to the next, especially in small populations.

Teacher's Note:
1. It is not a change within a generation.
2. Drift acts across generations.

Answer: (d) Melanization of peppered moth in industrial areas

Explanation:
1. The melanisation of the peppered moth is explained by natural selection, not by use and disuse. So it does not favour Lamarck.

Teacher's Note:
1. Dark moths survived better on dark trees.
2. Selection, not acquisition.

Answer: (d) Allen’s rule

Explanation:
1. Allen's rule says that extremities such as the tail and ears are shorter in cooler regions to reduce heat loss.

Teacher's Note:
1. Bergmann's rule concerns body size.
2. Allen means appendages.

Answer: (a) smaller populations

Explanation:
1. Genetic drift is effective only in small populations, since in large populations the random changes average out.

Teacher's Note:
1. Founder effect is an example.
2. Small population means drift.

Answer: (c) convergent evolution

Explanation:
1. Similar characters in organisms with different genotypes (ancestry) show convergent evolution.

Teacher's Note:
1. The structures are analogous.
2. Convergence gives similarity.

Answer: (b) Random mating

Explanation:
1. The gene ratio (allele frequency) remains constant under random mating, if no other factor acts, according to the Hardy-Weinberg principle.

Teacher's Note:
1. Mutation, migration and selection change frequencies.
2. Random mating keeps equilibrium.

Answer: (a) Discontinuous variations

Explanation:
1. Darwin believed in small, continuous variations. He did not accept discontinuous variations (mutations) as the basis of evolution.

Teacher's Note:
1. De Vries proposed mutation theory.
2. Darwin: gradual change.

Answer: (d) protective resemblance with the surroundings

Explanation:
1. Industrial melanism, the dark moths on sooty trees, is a case of protective resemblance (camouflage) with the surroundings.

Teacher's Note:
1. It is also an example of natural selection.
2. Camouflage protects from predators.

Answer: (d) Meat was not spoiled, when heated and kept sealed in a vessel

Explanation:
1. Pasteur's observation that microbes did not appear in sealed sterile meat or broth showed that life does not arise spontaneously from non-living matter.

Teacher's Note:
1. It supports biogenesis.
2. Sterile meat gave no microbes.

Answer: (c) Prevalence of pesticide resistant insects

Explanation:
1. The prevalence of pesticide-resistant insects supports natural selection, since the resistant variants survive and multiply.

Teacher's Note:
1. Cloning and transgenics are human techniques.
2. Resistance is selected by the pesticide.

Answer: (d) convergent evolution

Explanation:
1. When two species of different ancestry come to resemble each other by adaptation to similar environments, it is convergent evolution.

Teacher's Note:
1. The structures are analogous.
2. Different origin, same look.

Answer: (d) possible origin of life by combination of chemicals under suitable environmental conditions

Explanation:
1. The concept of chemical evolution is based on the possible origin of life by combination of chemicals under suitable environmental conditions.

Teacher's Note:
1. Oparin and Haldane proposed it.
2. Life began from chemicals.

Answer: (b) fitness is the end result of the ability to adapt and gets selected by nature

Explanation:
1. Fitness is the end result of the ability to adapt and be selected by nature. Darwinian variations are small and directional, and mutations are random.

Teacher's Note:
1. Cervical vertebrae are 7 in all mammals including whales, but camels also have 7.
2. Fitness means reproductive success.

Answer: (b) evolution of different species from a common ancestor

Explanation:
1. Adaptive radiation is the evolution of many different species from a common ancestor in the same geographic area.

Teacher's Note:
1. Darwin's finches are an example.
2. One ancestor, many forms.

Answer: (c) Adaptive radiation

Explanation:
1. Darwin's finches show adaptive radiation, with beaks modified to the food on the Galapagos islands.

Teacher's Note:
1. Different beaks arose from one ancestor.
2. Finches mean adaptive radiation.

Answer: (d) Individuals mate selectively.

Explanation:
1. Hardy-Weinberg equilibrium needs random mating, a large population, and no mutation, selection or migration. Selective mating disturbs it.

Teacher's Note:
1. The allele frequency then remains constant.
2. Selective mating breaks equilibrium.