16.4.2 Sexual Reproduction in Humans, pt 2

Fertilisation

fusion of nuclei from male gamete & female gamete

Fertilisation usually occurs in the

oviduct

Z__: f__ egg

zygote, fertilised

E__
> ball of c__ that implant into the u__’ walls

embryo, cells, uterus

Growth & development of foetus:
> early stages: ↑c__
> later stages: ↑s__

complexity, size

Z__ → e__ → f__

zygote, embryo, foetus

Amniotic sac: p__ baby & makes a__ f__

protects, amniotic fluid

Amniotic fluid: s__ & p__ f__ (s__ absorber)

surrounds, protects foetus, shock

Umbilical cord: a__ f__ to p__ & contains b__ v__ to transport b__

attaches foetus, placenta, blood vessels, blood

Placenta
> site of e__ via d__:
>> foetus receives __ + d__ n__
>> foetus removes __ + u__

exchange, diffusion, o2, dissolved nutrients, co2, urea

Placenta
> acts as b__ to some t__ & pathogens
>> but some pass across placenta & affect the foetus
>>> e.g. n__, r__ virus

barrier, toxins, nicotine, rubella