Reproduction Flashcards
Fertilisation
When a haploid sperm fuses with a haploid ovum
External Fertilisation
-Occurs outside of the body
-Usually occurs in water e.g fish and amphibians
-Eggs are laid in the water and sperm is released around them
-Not all eggs are fertilised and some are eaten by predators
-Many eggs are release to increase chances of successful reproduction
Internal Fertilisation
Occurs inside the body.Sperm is released in the female and the sperm swims to the egg.This allows for terrestrial animals to reproduce because gametes can’t survive dry environment.Fish,birds,mammals
There types of embryo development
-Ovipary
-Ovovipary
-Vivipary
Type of development where the eggs are laid and develops and hatches outside
Ovipary
Ovovipary
Internal fertilisation where eggs remain the the female and hatch inside ,obtain nourishment form the yolk
Vivipary
Development where the embryo develops inside the female ,nourishment form the placenta
Amniotic egg consists of ?
Egg that consists of
amnion carion
albumen,allantois,embryo ,air pocket and yolk
Function of Amnion
Secretes fluid called amniotic fluid which provides freedom for movement for the embryo ,acts as a shock absorber and regulates temperatures
Shell of amniotic egg
Calcareous/ leathery
-pores allow for gaseous exchange
-she’ll protects egg
allantois
bladder like structure that stores nitrogenous waste from embryo
albumen
stores protein from developing embryo
Precocial
Type where practically fully developed after hatching.Can move out of the nest after 2-3 days .Nests found on the ground .
Atricial
type of development where the young are not fully developed after birth.Stil Nest up in the sky ,the young are helpless after hatching .Yolk has less energy and they are poorly developed
Flying birds
Gametogenisis
The formation of gametes through mitosis .During puberty
Spermatogenisis
Germinal epithelial cells of the seminiferous tubule give rise to sperm.Sertolis and which protect and nourish the spermatozoon.Leydig cell secrete testosterone
Cells that secrete testosterone
leybig
acrosome
consists of enzymes that dissolve the surface of the egg
the middle piece of the sperm contains
mitochondria
Oogenisis
The formation of ova
The germinal epithelial goes through mitosis to form primary follicles.FSH is released and then one cells enlarges and undergoes meiosis and for 4 haploid cells form.One matures and 3 disintegrate.
Left over Graafian follicle is the
Corpus lutuem