Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Sexual Reproduction in Flowering Plants

Question:

Read the passage and answer the following questions .

In the process of sexual reproduction in angiosperms, the seed serves as the final product. It is formed from a fertilized ovule and is typically enclosed within a fruit. A seed is composed of several parts, including seed coats, cotyledons, and an embryo axis. The cotyledons of the embryo are simple structures that are often thick and swollen, storing food reserves, particularly in legumes. Mature seeds can be classified as albuminous (with endosperm) or ex-albuminous (with reduced endosperm). The integuments of the ovules harden to become protective seed coats, and a small pore called the micropyle remains, enabling the entry of oxygen and water during seed germination. As the ovules develop into seeds, the ovary undergoes transformation into a fruit. This simultaneous process involves the ovules turning into seeds, and the ovary walls developing into the fruit's pericarp. Fruits come in different types, including fleshy fruits like guava, orange, and mango, as well as dry fruits such as groundnut and mustard. Many fruits have evolved mechanisms for the dispersal of seeds.

The micropyle remains as a small pore in the seed coat, what function it provides ?

(i) Provide nutrition .

(ii) Facilitates entry of oxygen into the seed during germination.

(iii) Facilitates entry of water into the seed during germination.

Options:

(i) and (ii)

(i) and (iii)

(i) , (ii) and (iii)

(ii) and (iii)

Correct Answer:

(ii) and (iii)

Explanation:

The correct answer is Option (4) – (ii) and (iii)

Integuments of ovules harden as tough protective seed coats. The micropyle remains as a small pore in the seed coat. This facilitates entry of oxygen and water into the seed during germination.
As the seed matures, its water content is reduced and seeds become relatively dry (10-15 per cent moisture by mass). The general metabolic activity of the embryo slows down. The embryo may enter a state of inactivity called dormancy, or if favourable conditions are available (adequate moisture, oxygen and suitable temperature), they germinate.

During seed germination, the embryo inside the seed reactivates and starts to grow. Water is an essential requirement for this process as it triggers various metabolic activities within the seed, leading to cell expansion, enzyme activation, and other vital biochemical processes. The entry of water through the micropyle helps to rehydrate the dormant tissues and activate cellular metabolism.