C:N ratio of plant tissues is:

Correct option is A

Explanation:
The C:N ratio (Carbon to Nitrogen ratio) is an important ecological and biochemical parameter used to understand the composition of organisms:
· Plants have high C:N ratios, typically ranging from 20:1 to 40:1, because they are composed mainly of cellulose and other carbon-rich compounds and have relatively less nitrogen.
· Bacteria, on the other hand, are nitrogen-rich and have low C:N ratios, typically around 4:1 to 6:1, due to their high protein and nucleic acid content.
Hence, plant tissues have a higher C:N ratio compared to bacteria.
Information Booster:
· C:N ratio influences decomposition rates, nutrient cycling, and microbial activity in ecosystems.
· Materials with a high C:N ratio (like dry leaves) decompose slowly, while those with a low C:N ratio (like manure) decompose faster.
Additional Information:
· (b) Lower than C:N ratio of fungi – Incorrect. Fungi have moderate C:N ratios (~10:1), still lower than plants.
· (c) Lower than C:N ratio of terrestrial animals – Incorrect. Animals have lower C:N due to high protein content.
· (d) Lower than C:N ratio of aquatic animals – Incorrect. Aquatic animals also have lower C:N ratios than plants.