KS3 Human Reproduction Knowledge Organiser

Vocabulary flashcards covering human reproductive anatomy, gametes and their adaptations, puberty, the menstrual cycle, embryonic and foetal development, and the effects of maternal lifestyle.

Adaptation

A specific feature that allows a specialised cell to carry out a particular function.

Biological sex

Determined by the reproductive organs a person has, the sex chromosomes in their body, and the hormone levels they produce.

Conception

The process of becoming pregnant.

Egg cell

The female sex cell, produced by the ovaries.

Embryo

An unborn or unhatched offspring in the early stages of development. In humans, this is up to the end of the eighth week after conception.

Female (biological sex)

The sex typically given to an individual who produces egg cells, has XX chromosomes, and produces higher levels of the hormone oestrogen.

Male (biological sex)

The sex typically given to an individual who produces sperm cells, has XY chromosomes, and produces higher levels of the hormone testosterone.

Hormone

A chemical that is produced naturally within the body and released into the bloodstream to send messages to other parts of the body.

Oestrogen

The main female reproductive hormone, produced by the ovaries, which is involved in thickening the uterus lining.

Puberty

The period of time in a person's life when they become sexually mature, causing physical and emotional changes that affect males and females differently because of hormones.

Sperm cell

The male sex cell, produced by the testes.

Testosterone

The main male reproductive hormone produced by the testes, which stimulates sperm production.

Vulva

The external female genitals.

Penis

Allows urine and semen to pass out of the male's body.

Testis

Produces sperm cells and releases the male sex hormone testosterone.

Urethra

A tube that carries urine and semen, featuring a ring of muscle to keep these fluids separate.

Scrotum

A bag of skin that contains the testes.

Gland (male reproductive system)

Produces fluids that mix with sperm cells to make semen.

Sperm duct

Carries sperm cells from the testes to the urethra.

Vagina

A muscular tube that leads from the cervix to the outside of the body.

Cervix

A ring of muscle at the lower end of the uterus that keeps the baby in place during pregnancy.

Ovary

Contains hundreds of undeveloped egg cells, where every month an egg cell matures and is released.

Uterus (womb)

The organ where the baby develops during pregnancy.

Oviduct (fallopian tube)

Carries egg cells from the ovaries to the uterus.

Uterus lining (endometrium)

A blood-rich layer of tissue in which an embryo implants, and which is lost each month during menstruation.

Ejaculation

The release of semen from the penis.

Fertilisation

The fusion of male and female gametes, occurring when the nucleus of a sperm cell fuses with the nucleus of an egg cell.

Foetus

An unborn offspring after the embryo stage of development; in humans, this is from the eighth week after conception.

Gamete

A sex cell.

Gestation

The time between conception and birth, during which the baby is developing in the uterus, with an average human duration of $40\,\text{weeks}$.

Implantation

The attachment of the embryo to the lining of the uterus at the start of pregnancy.

Menstrual cycle

The monthly cycle of changes in the ovaries and the lining of the uterus to prepare for fertilisation, having an average length of $28\,\text{days}$.

Menstruation

The process of releasing blood and tissue from the lining of the uterus as part of the menstrual cycle; also known as a period.

Miscarriage

The death of a foetus before $24\,\text{weeks}$ of pregnancy.

Stillbirth

The birth of a baby that has died in the uterus after $24\,\text{weeks}$ of pregnancy.

Offspring

The children or young of an organism.

Ovulation

The release of a mature egg cell from an ovary, occurring on day $14$ of the menstrual cycle.

Placenta

An organ that develops in the uterus during pregnancy, responsible for transferring oxygen and glucose from the mother to the developing foetus, as well as removing waste products.

Semen

The mixture of sperm cells and fluid released during ejaculation in males.

Sexual intercourse

Sexual contact involving penetration, e.g. the insertion of the penis into the vagina.

Umbilical cord

The cord which connects the placenta to the foetus.

Zygote

A fertilised egg cell that divides several times to form a ball of cells called an embryo.

Acrosome

A covering on the head of a sperm cell that releases enzymes to digest the egg cell membrane.

Flagellum (sperm tail)

The tail of a sperm cell that allows it to move towards the egg cell to fertilise it.

Midpiece (sperm cell)

The section of a sperm cell that contains many mitochondria to release energy for movement.

Sudden infant death syndrome (SIDS)

A condition whose risk increases when mothers smoke cigarettes during pregnancy.

Foetal alcohol syndrome

A condition caused by heavy alcohol consumption by a mother during pregnancy, which can result in learning difficulties and behavioural problems.