Question

Roots of mangroves are

• A. Positively geotropic
• B. Negatively geotropic
• C. Photonastic
• D. Seismonastic

Answer 1

The correct option is B

Negatively geotropic

The correct option is B

Explanation of the correct option:

1. Negative geotropism is the tendency of plant stems and other parts to grow upwards that is growing against the force of gravity.
2. Mangrove plants are characterized as breathing roots or pneumatophores.
3. The pneumatophores roots grow in the upward direction vertically and are negatively geotropic.
4. In mangroves, the exchange of oxygen and carbon dioxide takes place through the negatively geotropic roots.

Explanation of the incorrect option:

Option A:

Positive geotropism refers to the growth of plants in a downward direction due to the force of gravity acting on it.

Option B:

Photonastic movement can be defined as the movement of plants or parts of a plant in response to light and there is no defined direction.

Option C:

Seismonastic movement is the type of movement of the plant or response of the plant against the stimulus.

Final answer: Roots of mangroves are negatively geotropic.