9. Reproduction Flashcards
Fertilisation
The fusion of the nuclei from a male gamete (sperm) and a female gamete (egg cell/ovum) in the oviduct (usually to form a zygote (fertilised egg cell)
Embryo
In early development the zygote forms a embryo which is a ball of cells that implants into the wall of the uterus.
What dies acrosome in sperm do?
Contains lots of digestive enzymes to get into the egg,also DNA.
When is the human embryo then called a foetus?
After 8 weeks.
Placenta
A plate-like structure that allows for the exchange of dissolved nutrients, gases and excretory products. It also provides a barrier to toxins and pathogens.. Food and oxygen diffuse from the mothers blood into the blood of the foetus. CO2 and other waste diffuse through the placenta from the foetal blood, into the mothers blood.
What do some pregnant women take folic acid supplements?
Promotes growth and development and helps avoid birth defects.
What is the effect of drinking alcohol while pregnant?
Baby may be born underweight or brain-damaged.
What is the effect of smoking while pregnant?
Oxygen supply is reduced by nicotine and carbon monoxide.
What is the effect of taking drugs while pregnant?
Blood vessels and heart may be damaged. Baby maybe small, born early of dead.
How could the rubella virus effect a baby?
Embryo infected and cant develop properly. May be born deaf or blind.
What is the sucking reflex?
When the baby is placed next to its mothers breasts it sucks at the nipples. Sucking stimulates the release of oxytocin hormone which causes mammary glands to squeeze out milk. (Lactation)
What is the milk made in the first few days called after birth by mother?
Colostrum, it contains many antibodies and very little food.
Bottle feeding and bottle milk?
Formula milk is based on cows milk. Sugars and other substances are added to make it more like human milk.
Puberty
The period during which adolescents experience maturity of the sex organs the production of gametes.
What do the chemicals hormones do?
Bring about the development and regulation of ‘secondary sexual characteristics’
