AIPMT 2010 Mains question paper with solutions

1. First, work through each individual statement and identify the correct term(s) to fill in the blanks.

2. Statement (A): Wings of a butterfly and a bird look alike (similar function) despite coming from unrelated ancestors — this is a classic case of convergent evolution, not divergent.

So, (A)-(i) = convergent.

3. Statement (D): According to Darwin's theory of natural selection, evolution occurs due to the accumulation of small variations over generations, coupled with the survival of the fittest individuals who pass these variations on.

So, (D)-(i) = small variations, (D)-(ii) = survival.

4. Now check which option correctly fills in two of these statements together.

Option B fills in (D) with "small variations" and "survival," and also correctly fills (A) with "convergent" — both match what we derived.

5. The other options either mismatch the terms (e.g., calling A "convergent" is right, but pairing it wrongly elsewhere) or use incorrect terms for statements B and C.

6. Hence, the answer is B.

1. Understand the nitrogen cycle diagram - The diagram shows different processes that link atmospheric nitrogen to nitrogen compounds in soil and to living organisms.

2. Identify blank A - The label at A corresponds to the process where fixed nitrogen compounds (such as nitrates) are converted back into atmospheric nitrogen gas, which is called denitrification.

3. Identify blank B - The label at B corresponds to the breakdown of organic nitrogenous compounds (like proteins) from dead organisms into ammonia, which is called ammonification.

4. Identify blanks C and D - Based on the flow of nitrogen compounds from soil into living organisms, blank C corresponds to plants (which absorb nitrogen compounds from soil) and blank D corresponds to animals (which obtain nitrogen by consuming plants).

5. Conclusion - Putting it together: A - Denitrification, B - Ammonification, C - Plants, D - Animals. Hence, the answer is Option B.

1. Understand how to interpret a pedigree chart. A pedigree chart shows the pattern of a trait's appearance across a family, allowing inferences about the genotypes of the parents based on the traits observed in their children.

2. Analyse the pattern shown in the given pedigree. Since both daughters in this pedigree are shown to have received the trait-associated gene from their parents, while the son could be either normal or affected, this specific mixed pattern among the offspring points to one parent carrying two different alleles.

3. Determine which parent must be heterozygous. Given that this variable outcome among the sons (normal or affected) can only arise if the female parent carries both a normal and an affected allele together,

this means the female parent is heterozygous for this trait.

4. Eliminate the other options based on this reasoning. Since this specific pattern is consistent with the described inheritance, claims that the trait 'could not be colourblindness,' that a normal daughter was impossible, or that the male parent is homozygous dominant do not hold up against the pedigree's actual pattern.

Hence, the correct answer is Option B, The female parent is heterozygous.