NEET 2024 (Re-Examination) question paper with solutions

1. Evaluate statement A. Cellular respiration is fundamentally an oxidation process in which the carbon-carbon (C-C) bonds of complex organic molecules like glucose are progressively broken down to release energy.

This statement is correct.

2. Evaluate statement B. Cellular respiration includes glycolysis, the Krebs' cycle, and the electron transport chain. Since glycolysis occurs in the cytoplasm (not inside the mitochondria), the claim that the entire process happens in mitochondria is incorrect.

3. Evaluate statement C. When oxygen is limited, as is common in germinating seeds, cells switch to fermentation, an anaerobic pathway that regenerates $NAD^+$ without needing oxygen.

This statement is correct.

4. Evaluate statement D. After glycolysis produces pyruvate, its next fate is not fixed — it may be converted to ethanol, lactic acid, or enter the Krebs' cycle as acetyl-CoA, depending on the organism and the availability of oxygen.

This statement is correct.

5. Evaluate statement E. In the electron transport chain, $O_2$ serves as the terminal electron acceptor. When it accepts electrons, it becomes reduced and combines with protons to form water.

This statement is correct.

6. Combine the correct statements. A, C, D, and E are correct, while B is incorrect.

Hence, the answer is Option A: A, C, D, E only.

1. The figure shown is of a strawberry, which is a well-known example of a false fruit.

2. In a false fruit, the fleshy, edible part that we eat is not derived from the ovary wall (as in a true fruit) but instead develops from the swollen, receptacle-like base of the flower called the thalamus.

3. The actual ovaries in a strawberry become the tiny dry structures (achenes) scattered on the surface, while the fleshy part marked 'x' is the enlarged thalamus.

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

1. Look at the height trait first. Since all the progeny (both types) are tall, and no dwarf plants appear at all, the parent cannot be heterozygous for height, because a heterozygous $Tt$ parent selfed would produce some dwarf ($tt$) offspring too.

Therefore, the parent must be homozygous dominant for height:

2. Now look at the seed shape trait. Since the progeny includes both round-seeded and wrinkled-seeded plants, this segregation of two different phenotypes can only occur if the parent is heterozygous for seed shape:

3. Combine both findings. Given that the parent is $TT$ for height and $Rr$ for seed shape,

Hence, the correct answer is Option D.