AIPMT 2010 Prelims question paper with solutions

1. Recall which organelles possess their own DNA. Mitochondria is a semi-autonomous structure within the cytoplasm of eukaryotic cells that carries out aerobic respiration and contains its own circular DNA.

2. Understand why this DNA matters. Since mitochondria carry out the Krebs cycle and the electron transport system (ETS), they are also called the cell's energy production site, and their own DNA supports independent synthesis of some respiratory proteins.

3. Eliminate the other options. Dictyosome (Golgi body), peroxisome, and lysosome do not contain their own DNA — they rely entirely on nuclear DNA for their protein components.

Hence, the answer is B. Mitochondria.

1. Recall the timeline of key foetal milestones.

Human pregnancy development follows a specific timeline: the embryo's heart forms after one month, limbs and digits develop by the end of the second month, and major organ systems are formed by the end of 12 weeks (third month).

2. Identify the milestone in question.

After these earlier stages, the first movements of the foetus and the appearance of hair on its head are usually observed during the fifth month of pregnancy.

3. Note the following milestone for context.

By the end of 24 weeks (sixth month), the foetal body becomes covered with fine hair, and the eyelids separate with eyelashes forming.

4. Eliminate the incorrect options.

The third, fourth, and sixth months correspond to other developmental stages, not this specific milestone of first movement and head hair appearance.

5. Conclusion.

Since these specific milestones occur during the fifth month, this is the correct answer.

Hence, the answer is B.

1. Recall the family that China rose (Hibiscus rosa-sinensis) belongs to.

China rose belongs to family Malvaceae.

2. Recall the characteristic androecium feature of Malvaceae.

In Malvaceae, the numerous stamens have their filaments fused into a single tube (bundle) surrounding the style, a condition called monadelphous.

3. Eliminate the other options.

Diadelphous (fusion into two bundles) is seen in Fabaceae, polyadelphous (fusion into more than two bundles) is seen in Citrus, and polyandrous simply means numerous free (unfused) stamens — none of these apply to China rose's actual fused single-bundle condition.

Hence, the answer is option A: monadelphous.