Grade 12 Life Sciences Paper 1: Core Concepts and Terminology

Spermatogenesis

The process under the influence of testosterone in which diploid cells in the seminiferous tubules of the testes undergo meiosis to form haploid sperm cells.

Follicle-Stimulating Hormone (FSH)

The pituitary hormone that stimulates the development of a primary follicle into a mature Graafian follicle.

Scrotum

A skin sac that protects the testes and holds them outside the body at a temperature that is $2\text{ }^\text{o}\text{C}$ to $3\text{ }^\text{o}\text{C}$ below normal body temperature ($37\text{ }^\text{o}\text{C}$) for optimal sperm production.

Epididymis

The coiled structure where immature sperm cells are stored and mature.

Sperm duct (vas deferens)

The muscular tube that transports mature sperm cells from the epididymis to the urethra.

Seminal vesicle

An accessory gland that produces a nutrient-rich fluid providing energy for sperm cells.

Prostate gland

A gland that produces an alkaline fluid to neutralise acids found in the vagina and urethra that would otherwise kill sperm cells.

Cowper's gland

An accessory gland producing mucus that aids in the lubrication and movement of sperm cells.

Acrosome

The vesicle at the tip of the sperm head containing digestive enzymes that break down the outer wall/membrane of the ovum for fertilisation.

Testosterone

A hormone produced by the testes that stimulates the development of male secondary sexual characteristics and the maturation of sperm cells.

Oogenesis

The process occurring in a monthly cycle where diploid cells in the ovary undergo mitosis to form follicles, and under the influence of FSH, one cell enlarges and undergoes meiosis to produce a single mature haploid ovum.

Fallopian tube

The structure connecting the ovaries to the uterus that transports egg cells and serves as the site of fertilisation.

Endometrium

The blood vessel-rich inner lining of the uterus where the blastocyst implants and the placenta develops.

Luteinising Hormone (LH)

The pituitary hormone that triggers ovulation and stimulates the conversion of the ruptured follicle into the corpus luteum.

Oestrogen

The hormone secreted by the developing Graafian follicle that starts the repair and thickening of the endometrium.

Progesterone

The hormone secreted by the corpus luteum that further thickens and maintains the endometrium in preparation for possible implantation.

Corpus luteum

The glandular endocrine structure formed in the ovary from the remnants of the Graafian follicle following ovulation.

Ovulation

The release of a mature ovum from the Graafian follicle in the ovary under the influence of LH.

Ovarian cycle

The repeating monthly sequence of events in the ovary, comprising the development of the Graafian follicle, ovulation, and corpus luteum formation.

Uterine cycle

The cyclical changes in the thickness of the endometrium regulated by oestrogen and progesterone across the menstrual cycle.

Menstruation

The shedding and discharge of the blood vessel-rich endometrium through the vagina caused by a drop in progesterone levels when fertilization does not occur.