release fluids that have nutrients so the sperm cells have energy
scrotum
supports the testes which is outside the body
foreskin
protects the penis
penis
to place the sperm cellsinside the female
sperm ducts
where sperms travel through
the mixture of sperm cells and fluids is called semen which leaves the body through the urethra
the male gamete
sperm
sperms are specialised cells that are streamlined shaped to swim through body fluids and contains genetic info.They also have lots of mitochondria in a mitochondrion that releases energy.The tail of the sperm is called a flagellum and it helps it swim. The top of the head contains enzymes that attack the outside of the egg cell so it can fertilise it
the female reproductive system includes
oviduct, ovary, uterus, cervix, bladder, vagina and urethra
ovaries
contain egg cells
oviduct
has cilia that sweeps the egg cell towards the uterus
uterus
where a baby develops
cervix
holds the baby in place during pregnancy
vagina
provides a passageway for the uterus lining, egg cell, semen and the baby during childbirth
as a couple prepares for intercourse
the man's penis fills with blood and he gets an erection. the woman's vagina becomes moist to reduce friction
during sex, the penis is inserted into the vagina and the man moves it back and forth. this stimulates it to pump semen into the vagina. this process is called ejaculation. the semen is sucked up through cervix. small movements of the uterus wall carry it to the oviducts
men eject 300 million sperms but only one burrows into egg and fertilises it
during fertilisation, the nucleus of the sperm cell and the nucleus of the egg cell fuse
fertilisation occurs in the oviduct
in all our cells we have 46 chromosomes, half from ur mom and half from ur dad
an extra chromosome causes down syndrome
when the egg cell is fertilised, all the characteristics will be decided and it is unique genetic coding
a fertilised egg
zygote
the zygotesplits into two, then each of those cells split again and they keep splitting as the zygote travels towards the uterus
when the zygote becomes a ball of cells it is called a embryo
the embryo sinks into the soft lining of the uterus. this process is called implantation. the woman is pregnant
if implantation doesn't happen you can't get pregnant
after implantation, the embryo continues to grow and is surrounded by amniotic fluid. the watery substance protects the fetus. the fluid is contained in a bag called the amnion
a placenta is an organ that is attached to the uterus lining.it takes nutrients, water and oxygen from the mother's blood these go into the baby's blood.waste materialsfrom the baby go into the mother's blood
the umbilical cord carries the baby's blood to and from the placenta
if people do drugs or drink when they are pregnant this may harm the baby or kill it
the mother's blooddoes not mixwith the baby's as the mother's blood pressure is too high and will damage the foetus's blood vessels
identical twins
same zygote, genetically identical, share a placenta