In germinating seeds fatty acids are degraded exclusively in the?

The correct option is B

Glyoxysomes

The correct option is B.

Explanation of the correct option:

1. Glyoxysomes are specialized peroxisomes found only in plant cells and filamentous fungi.
2. Glyoxysomes occur only in fat-rich plant cells, where they take part in β-oxidation of fats and perform the glyoxylate cycle.
3. It catalysis the formation of acetyl CoA from fatty acids and stores them within the germinating seeds.
4. This organelle also helps in photorespiration and nitrogen metabolism in root nodules.

Explanation of the incorrect options:

Option A:

1. Peroxisomes are organelles that carry out oxidation reactions and produce hydrogen peroxide.
2. Beta-oxidation of peroxisomes contributes to embryogenesis, seedling growth, and stomatal opening.

Option C:

1. Proplastids are minute cytoplasmic structures from which plastids are formed.
2. These help in the synthesis of amino acids for protein production and the synthesis of fatty acids for lipid production.

Option D:

1. Mitochondria are membrane-bound organelles that generate the chemical energy needed to perform cell reactions.
2. These are also called powerhouses of cells.

Final answer: In germinating seeds, fatty acids are degraded exclusively in the glyoxysomes.