Q.48. In a typical angiosperm under natural condition, primary meristems are usually established
during
(A) Gametogenesis
(B) Embryogenesis
(C) Vegetative phase development
(D) Secondary growth

Primary meristems in typical angiosperms form during embryogenesis under natural conditions, marking the initial setup for plant growth.

Correct Answer

The right choice is (B) Embryogenesis. This stage lays down the foundational apical meristems at the embryo’s shoot and root tips, leading to primary growth tissues like protoderm, ground meristem, and procambium.

Option Breakdown

(A) Gametogenesis

Gametogenesis produces haploid gametes such as pollen and embryo sacs, focusing on reproductive cells rather than meristem establishment.

(B) Embryogenesis

During embryo development, bipolar organization emerges with shoot and root apical meristems, plus primary meristems (protoderm for epidermis, ground meristem for cortex/pith, procambium for vascular tissues).

(C) Vegetative Phase Development

This phase involves post-germination growth where existing primary meristems from the embryo drive elongation of stems and roots, but they originate earlier.

(D) Secondary Growth

Secondary growth arises from lateral meristems like vascular cambium and cork cambium, producing wood and bark after primary growth completes.