AIPMT 2008 question paper with solutions

1. This question checks recall of the location of a major international environmental summit.

2. The World Summit on Sustainable Development (2002) was held in Johannesburg, South Africa, where 190 countries pledged their commitment to achieve, by 2010, a significant reduction in the current rate of biodiversity loss at global, regional, and local levels.

3. Why the other options are wrong: Sweden, Brazil, and Argentina did not host this particular summit — note that Brazil (Rio de Janeiro) instead hosted the earlier 1992 Earth Summit.

Hence, the answer is Option A.

1. Recall what senescence means: senescence refers to the changes that occur in an organism between maturity and death — essentially, the process of ageing at the cellular or organ level.

2. Understand what happens during senescence: as senescence progresses, there is a characteristic deterioration in cell functioning, as cells become progressively less efficient at maintaining and replacing their vital components. Given this,

$$\text{Maturity} \rightarrow \text{Senescence (deteriorating cell function)} \rightarrow \text{Death}$$

3. Identify where this active developmental process is best indicated: senescence as an active developmental process in a flowering plant's growth and functioning is indicated in processes like vessel and tracheid differentiation and leaf abscission, since these involve programmed, active cellular breakdown as part of normal development.

4. Eliminate the other options: annual plants (option A, likely referring to whole-plant senescence at the end of a life cycle) and floral parts and leaf abscission alone (options B and D) are each too narrow or specific compared to the combined process described in option C.

Hence, the correct answer is C. vessels and tracheid differentiation leaf abscission.

1. Recall that archaea form a distinct domain of prokaryotic organisms that includes methanogens, thermoacidophiles, and halophiles, adapted to extreme environments.

$$\text{Archaea} = \{\text{Methanogens, Thermoacidophiles, Halophiles}\}$$

2. Rule out Options A, B, and C: archaea are not completely different from both other groups, nor completely different from prokaryotes alone, nor do they resemble eukarya in all respects — these are overly absolute and inaccurate claims.

3. Since archaea actually possess certain unique biochemical and structural features (such as ether-linked membrane lipids and specific enzymes) not found in either typical bacteria (eubacteria) or eukaryotes, they are considered a distinct domain with novel characteristics.

Hence, the correct answer is Option D.