Biology Test - 18

The first step in the fertilization process is the transfer of pollen from the anther to the stigma of the flower.

After fertilization, the zygote develops into a seed, which contains the embryo and will eventually grow into a new plant.

The areas on the exterior of the seminiferous tubules called interstitial spaces, contain small blood vessels and small clusters of big, polygonal cells called Leydig cells or interstitial cells. Leydig cells synthesize and secrete hormones (testicular) called androgens.

The female external genitalia include mons pubis, labia majora, labia minora, hymen and clitoris. The vagina is a fibro-muscular tube measuring 7.5-10cm in length, extending from the cervix of the uterus to the vestibule on the outer side.

A functional mammary gland is distinctive of all female mammals. The mammary glands are paired structures (breasts) that contains the glandular tissue and variable amounts of fat.

Testosterone is a hormone that plays a crucial role in the growth, maintenance, and functioning of secondary sex organs in males. It is primarily produced by the Leydig cells in the testes.

Testosterone is responsible for the development of male secondary sexual characteristics such as the growth of facial and body hair, deepening of the voice, and enlargement of the testes and penis during puberty. It also promotes the growth and maintenance of other reproductive structures such as the seminal vesicles, which produce seminal fluid, and the prostate gland.

Additionally, testosterone is involved in regulating sexual function and libido, sperm production, and the overall well-being and vitality of males. It influences the maintenance of muscle mass and bone density and plays a role in red blood cell production.

In summary, testosterone is essential for the growth, maintenance, and functioning of secondary sex organs and is vital for the overall development and reproductive health of males.

The mammary glands are made of glandular tissue. The glandular tissue of each breast is divided into 15-20 mammary lobes containing clusters of cells called alveoli.

Entomophily is a common type of zoophily wherein the pollen grains of mature anthers of a flower are transferred to a mature stigma of another flower through insects like beetles, moths, butterflies, wasps, bees, etc.

A 40cm long vas deferens emerges from the cauda epididymis on each side and leaves the scrotal sac and enters the abdominal cavity through the inguinal canal.

Mammary alveoli are small sacs in the mammary glands where milk is produced and stored in mammals. Bile is secreted by the liver that helps digest lipids. Sweat is secreted by the sweat glands to maintain body temperature.