terms Flashcards
fission
animal breaks into two similarly sized pieces
budding
large parent produces outgrowths that enlarge and eventually separates
fragmentation
animal breaks into many pieces and each form into a functional individual
parthenogenesis
egg develops without fertilization
(clone or haploid)
hermaphroditism
both male and female reproductive systems monoecious
dioecious
animals that can switch sexes
most common is sessile animals
more favourable during environmental uncertainty to increase genetic variability
life cycle
gametes, fertilization, cleavage, morula-hollow, blastula, gastrulation, morphogenesis, organogenesis
yolk types- isolecithal
small amount, even distribution
yolk types- mesolecithal
medium amount, uneven dis
yolk types- telolecital
large amount, even distribution
organogenesis
germ layers develop into rudimentary organs
morphogenesis
involves both gastrulation and organogenesis
-change in cell shape, cell migration, cell death
developing zygote- oviparity
embryo deposit outside moms body to develop and hatch (external brooding)
build nest to protect/hide eggs
lower embryo survival
developing zygote- ovoviviparity
embryo stored and hatched inside moms body (egg nourished by yolk)
internal brooding
live young emerge- egg are growing inside mom
developing zygote- viviparity
embryo retained and developed in moms body- more expensive
higher rate of survival