Flashcards in Developement Deck (11)
Series of progressive changes in form and function that occur during organisms life cycle
When does development take pace?
Embryonic stage precedes birth, continues until death
What are the key stages of development?
fertilisation, cleavage, gastrulation, organogenesis, morphogenesis
How is amniote development specialised?
Adapted structures that allow for the movement of reproduction into dry environment, by shell and by uterus, membranes provide a life support system for further embryonic development
What are the embryos of amniotes surrounded by?
Amniotic fluid, surrounded by sac called amnion membrane
What extra embryonic membranes develop in the click?
Chorion, amnion, yolk sac and allantois
What is the chorion?
Completely surrounds the embryo and other extraembryonic membranes, located outside the embryo. with amnion it exchanges gases between embryo and surrounding air
What is the amnion?
Encloses embryo in protective, fluid filled amniotic cavity, prevents dehydration and cushions mechanical shock
What is the allantois?
Functions as a disposal sac for certain metabolic wastes produced by the embryo. The membrane of the allantois functions as respiratory organ with the chorion.
Where does fertilisation take place in mammals?