life sciences - animal reproduction

FERTILISATION

process when sperm fuses with an egg to form a zygote

EXTERNAL FERTILISATION

occurs outside the body where females lay eggs and male releases sperm over them usually done in water

INTERNAL FERTILISATION

sperm is released inside the females body and swim towards the egg since sperm cannot survive in dry terrestrial environments

OVIPARY

development of the egg occurs outside the body 

OVOVIVIPARY

development of an egg that is retained inside the mothers body

VIVIPARY

development of an embryo within a females body

AMNIOTIC EGG

allows embryos of vertebrates to develop in a liquid

PRECOCIAL DEVELOPMENT

young are able to move immediately after catching

ALTRICIAL DEVELOPMENT

dependent on their mothers for food