AIPMT 2002 question paper with solutions

1. Recall the definition of a species: A species is a group of organisms capable of interbreeding with one another and producing fertile offspring.

2. Understand why habitat isn't the defining feature: While individuals of the same species often share a habitat, this alone is not what defines them as the same species — different species can also share the same habitat.

3. Understand niche uniqueness: According to ecological principles, no two individuals (or species) share exactly the same ecological niche — niche is more specific than just living in the same area.

4. Conclusion: The one property that is fundamentally and uniquely true for individuals of the same species is their ability to interbreed with each other.

Hence, the answer is Option C.

1. Recall the general rule for vessel distribution: Vessels are a more evolutionarily advanced water-conducting structure, and they are typically found in most angiosperms, giving angiosperms an efficiency advantage in water transport.

2. Recall the exception among angiosperms: A few angiosperms, such as Trochodendron, are exceptions and actually lack vessels, relying only on tracheids.

3. Recall the exception among gymnosperms: While most gymnosperms (like conifers, cycads) lack vessels and rely solely on tracheids, a few gymnosperm genera, such as Gnetum, Ephedra, and Welwitschia, are exceptions that do possess vessels.

4. Eliminate the other options: Claiming 'all angiosperms' or 'all gymnosperms' overstates the distribution since there are exceptions in both groups, and pteridophytes generally do not have vessels either.

Hence, vessels are found in most angiosperms and a few gymnosperms, so the answer is A.

1. In an anatropous ovule (the most common type found in angiosperms), the body of the ovule becomes completely inverted and fuses along its length with the funiculus on one side.

2. As a result of this inversion, the micropyle, which was originally at the apex, ends up pointing downward, close to the funicle and hilum.

3. This is in contrast to the orthotropous ovule, where the micropyle points upward since the ovule remains straight and unturned.

4. Hence, the answer is Option B: Downward.