Explanation

Endocrine glands secrete hormones directly into the bloodstream, without using ducts.

Examples include the pituitary, thyroid, adrenal, and pancreas (as an endocrine gland).

Explanation

Explanation

Insulin is a hormone secreted by the beta cells of the pancreas.

It helps regulate blood glucose levels by promoting glucose uptake into cells.

Explanation

Gastrin is a digestive hormone secreted by G-cells in the pyloric region of the stomach.

It stimulates the secretion of gastric acid (HCl), aiding in the digestion of food.

Explanation

After fertilization, the ovule develops into a seed, which contains the embryo and stored food.

The surrounding ovary turns into a fruit, while the ovule becomes the seed.

Explanation

Each megaspore mother cell undergoes meiosis, producing four haploid megaspores.

Out of these, typically one megaspore develops into the female gametophyte, but initially four are produced.

Explanation

The margin of the prothallus (the gametophyte stage of Adiantum) is typically one cell thick.

This thin edge helps in gas exchange and absorption, important for the fern’s reproduction and development.

Explanation

In Adiantum (a type of fern), the annulus is a specialized ring of thick-walled cells that helps in spore dispersal.

It typically occupies ¾ of the edge of the capsule, aiding in the dehiscence mechanism.

Explanation

Sori are clusters of sporangia found typically on the underside of fern leaves.

They play a key role in spore production and reproduction in ferns and other pteridophytes.

Explanation

The cell membrane is composed of roughly 40–50% lipids, primarily phospholipids and cholesterol.

These lipids form the bilayer structure, essential for membrane fluidity and barrier function.