7B Reproduction Flashcards
Offspring
The new organisms produced by reproduction.
Sexual Reproduction
Reproduction that needs two parents to produce offspring.
Gametes
Sex cells
Sperm
Gamete that males make
Egg
Gamete that females make
Fertilisation
Sperm enters an egg cell and nuclei fuse forming a fertilised egg cell.
External Fertilisation
The sperm and egg cell meet outside of the body.
e.g. fish
Internal Fertilisation
The sperm and egg cell meet inside the body.
What are the key features of external fertilisation?
Large numbers of eggs are produced because many get washed away. The parents don’t look after their young.
What are the key features of internal fertilisation
Fewer egg cells produced because sperm is more likely to reach egg. The parents usually look after their young.
Testes
Where sperm cells are made.
Scrotum
Bag of skin containing the testes.
Sperm Ducts
Sperm travels through here after leaving the testes.
Glands
Fluids are added to the sperm- it is now called semen.
Semen
Sperm with fluids added
Urethra
The tube the semen leaves the body through.
Ovary
Where the egg cells develop and are released from.
Oviduct
Tube lined with cilia (tiny hairs).
Cilia
Tiny hairs in the oviduct
Uterus
Where the baby will develop if the egg is fertilised.
Cervix
Ring of muscle between uterus and vagina.
Vagina
Part that leads from the cervix to the outside.
Puberty
When males start to produce sperm cells and egg cells in female start to mature.
Sexual Intercourse
The erect penis is inserted into the vagina.
Ejaculation
Semen is pumped out of the urethra.
Route the sperm takes
Vagina → sucked up through cervix → uterus → oviduct → meets egg cell
Implantation
If fertilisation occurs the cell starts to divide forming an embryo which will then sink into the uterus lining. The woman is now pregnant.
Amniotic Fluid
Watery fluid to protect growing embryo / foetus.
Amnion
Bag containing the amniotic fluid.
Placenta
Allows oxygen, food and water to be passed from mother’s blood into embryo’s blood. Waste materials (like carbon dioxide) pass from embryo’s blood into mother’s blood.
Umbilical Cord
Carries the embryo’s blood to and from the placenta.
Gestation Period
The time from fertilisation until birth.
Foetus
When an embryo develops a full set of organs we call it a foetus (around 8 weeks).
At what age does an embryo becomes a foetus?
Around 8 weeks
Ultrasound Scans
Produce images of foetus to check for problems.
What can cause harm to baby?
Alcohol, drugs, cigarette smoke and viruses can pass through placenta and harm foetus.
Premature
Baby born small and early.
Labour
The act of giving birth.
Stages of Giving Birth
contractions start and cervix begins to widen.
amnion breaks and amniotic fluid leaves vagina.
cervix at 10cm, stronger contractions pushes baby through.
Umbilical cord cut.
Afterbirth
The placenta is passed out of the vagina- end of labour.
Mammary Glands
Produces milk for babies- contains nutrients and antibodies to protect from disease
Sex Hormones
Released by brain, tests & ovaries- start puberty.
Changes to Boys During Puberty
Voice deepens, shoulders widen, hair grows, testes/ penis grow, sperm produced.
Changes to Girls During Puberty
Breasts develop, hair grows, hips widen, ovaries start to release eggs.
Menstrual Cycle
Days 1-5: uterus lining lost from body (menstruation)
Days 6-14: egg cell starts to mature and is released around day 14 (ovulation)
Days 14+: egg cell swept towards uterus, if not fertilised cycle starts again.
