Plant Reproduction and Germination

In angiosperms, pollen grains are typically shed at either the 2-celled stage (vegetative and generative cell) or the 3-celled stage (vegetative cell and two male gametes).

The exine of a pollen grain is composed of sporopollenin, which is one of the most resistant organic materials known, protecting the pollen from degradation.

In angiosperms, the female gamete is the egg cell, which is located within the embryo sac inside the ovule.

An orthotropous ovule is one where the micropyle, chalaza, and funiculus lie in a straight vertical line.

Microspore mother cells undergo meiosis to produce microspores, which then develop into pollen grains.

Gibberellins invigorate the combination of α-amylase and proteases compound in germinating grains of oats. They are associated with the transformation of starch into sugar. The proteases convert an inert β-amylase to the dynamic frame. The dynamic β-amylase and α-amylase together process starch to glucose which is prepared to meet the metabolic requests of developing life. 

When dry seeds are placed in wet soil they absorb water and increase in size because of this the hard seed coats get ruptured and process of germination of seed takes place.

The scutellum can also be considered in equivalence to thin cotyledon in monocots. It is very thin with a high surface area. It serves to absorb nutrients from the endosperm during germination. But it is not meant for protection of the embryo. Also, scutellum is not able to convert itself into a monocot leaf.

The option C is correct.

Micropyle is a narrow pore or passage formed by the projection of the integuments through which the pollen tube enters into ovule. Seeds contain micropyle through which water enters into the seed during germination.

During the beginning stage of the germination, the seeds take up water rapidly and this results in swelling and softening of the seed coat at an optimum temperature. By rupturing of the seed coats helps to emerge the radicle and the plumule to form a primary root. This stage is referred to as an imbibition. So, the correct answer is 'Massive imbibition of water’.

Seed germination is a fundamental process by which plant species grow from a single seed. One common example of seed germination is the sprouting of the seed of an angiosperm or gymnosperm. During its beginning stage, the seeds take up water for hydration. It is also used as a part of the aerobic respiration that also is a result of increased enzymatic activity.

The correct statements are 1 and 2 only.

The correct option is B.

A. Radicle- It is a embryonic root, which form root at the time of germination.

In hypogeal germination, the epicotyl elongates rapidly while the hypocotyl remains short, causing the cotyledons to remain below the soil surface. Conversely, epigeal germination features hypocotyl elongation pushing cotyledons above ground.