Question

REVIEW QUESTIONS

Which of the following structures widens the geographic range of a species and is an agent of dispersal?

(a) seed

(b) flower

(c) leaf

(d) root

Short answer

The correct answer is (a) seed.

Step-by-step solution

Step 1. Introduction

Seeds are the protective covering that encloses the developing embryo. It is formed by the ovule after fertilization takes place.

Step 2. Reason for incorrect options

• Flower is the reproductive organ of angiosperms which consist of the female and male reproductive parts.
• Leaves are the green flattened outgrowth from the stem of vascular plants that are specialized for photosynthesis. The chloroplast is found in the leaves.
• Roots are the parts of vascular plants that is located below the ground that helps absorb water and nutrients from the ground.

Step 3. Reason for correct option

• Seeds are the protective covering within which the embryo is contained and protected.
• Evolution of seeds in plants allowed plants to reproduce in absence of water.
• Several tissues in seeds prevent desiccation and reduce the dependency on constant supply of water.
• This helped plants to expand into dry lands and survive dry conditions.
• Seeds are dispersed easily by wind or animals.

Thus seeds helped widen the geographic range of a plant species and are an agent of dispersal.