Human and Plant Reproduction and Earth Systems

A comprehensive vocabulary review set covering key reproductive structures, physiological processes, contraceptive mechanisms, plant anatomy, and agricultural breeding concepts.

Oviduct (Fallopian Tube)

The female reproductive tube where fertilisation occurs, measuring approximately $10\text{--}13\text{ cm}$ in length and $0.5\text{--}1.2\text{ cm}$ in diameter, which carries mature egg cells from the ovary to the uterus.

Cervix

A ring of muscle forming the lower opening of the uterus that connects to the vagina and functions to keep the developing baby in place during pregnancy.

Endometrium

The blood-rich lining of the uterus where a fertilised embryo embeds to begin pregnancy, which is shed during menstruation if pregnancy does not occur.

Ovulation

The release of a mature egg from the ovary into the fallopian tube, typically occurring around Day 14 of the menstrual cycle in response to high levels of luteinising hormone (LH).

Menstruation

The monthly release of the blood-filled lining of the uterus through the vagina when pregnancy has not occurred, typically lasting between $5\text{--}7\text{ days}$.

Scrotum

An external pouch of skin containing the testes that provides protection and maintains a temperature approximately $2\,^\circ\text{C}$ cooler than body temperature for optimal sperm development.

Epididymis

A large coiled tube situated on the outer surface of each testis where newly produced sperm cells are stored and mature.

Vas Deferens (Sperm Duct)

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

Zygote

The single diploid cell formed when the nucleus of a sperm cell fuses with the nucleus of an egg during fertilisation, which subsequently divides into an embryo.

Placenta

The temporary maternal-foetal organ through which a developing baby inside the uterus absorbs nutrients and oxygen from the mother's bloodstream via diffusion.

Combined Pill

An oral chemical contraceptive containing synthetic oestrogen and progesterone that is approximately $99.7\%$ effective when used correctly, functioning by suppressing ovulation, thickening cervical mucus, and thinning the uterine lining.

Angiosperms

Flowering plants that constitute approximately $90\%$ of all plant species, utilising specialised flowers as reproductive organs to produce and transfer male and female gametes.

Stamen

The male reproductive structure of a flower, composed of a filament supporting an anther that produces pollen grains containing sperm cells.

Pistil (Carpel)

The female reproductive structure of a flower, consisting of a sticky pollen-catching stigma, an elongated style, and an ovary housing one or more ovules.

Self-Pollination

The transfer of pollen from the male anther to the female stigma of the same flower or same plant, providing reliable reproduction in stable environments at the expense of genetic diversity.

Cross-Pollination

The transfer of pollen grains from the anther of one plant to the stigma of a different plant of the same species, promoting genetic variation and population adaptability.

Monoecious

The condition in which a single plant bears separate male and female flowers, such as corn (maize) having male tassels located high above female silks to minimise self-pollination.

Sori

Clusters of spore-producing sporangia located on the underside of mature fern leaves.

Prothallus

A small, heart-shaped, free-living gametophyte structure that develops from a germinated fern spore and produces both sperm and egg cells.

Selective Breeding

The intentional breeding process by which humans choose parent organisms exhibiting desirable traits to reproduce, resulting in offspring with selected characteristics.