Question

Assertion (A): Both plants and animals exhibit chemical coordination.
Reason (R): Plant hormones regulate directional growth while in animals, hormones do not control directional growth.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is not the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Hint:

Plants and animals both use hormones for regulation, but in different ways and not limited to direction control.

Answer 1

The Correct Option is B

To determine if the assertion (A) and reason (R) are true and whether R correctly explains A, we must evaluate each statement:

Assertion (A): Both plants and animals exhibit chemical coordination.

This statement is true. Both plants and animals utilize chemical signals to coordinate various physiological processes. In plants, this involves hormones like auxins, cytokinins, and gibberellins, which control growth and development. In animals, it involves hormones like insulin, adrenaline, and others that regulate metabolism, growth, and more.

Reason (R): Plant hormones regulate directional growth while in animals, hormones do not control directional growth.

This statement is also true. In plants, hormones such as auxins play a key role in directional growth by promoting cell elongation on one side of the plant to cause bending toward light, known as phototropism. In contrast, animal hormones primarily regulate metabolic functions and internal homeostasis rather than directional growth.

While both statements are true, the reason (R) does not directly address or explain the concept of chemical coordination in both plants and animals, which involves broader functions than merely directional growth.

Thus, the correct response is: Both A and R are true but R is not the correct explanation of A.