REPRODUCTION Flashcards
1
Q
reproduction definition
A
a biological process during which a living organism produces offspring
2
Q
reproductive strategies
A
structural, functional and behavioral adaptations that increase the chances of fertilization and survival of offspring
3
Q
r-strategy
A
- when some animals use more energy in producing many offspring, but spend little time in parental care
- many offspring die before adulthood
4
Q
K-strategy
A
- animals which produce fewer offspring, use enormous amounts of energy for parental care
- offspring have better chance at survival
5
Q
external fertilization
A
- outside the female’s body
- courtship and specific mating behavior ensure eggs and sperm are released at the same time and place to inc
- pheromones are sometimes released by females
6
Q
how ext fert works
A
- gametes are released into water where fert takes place, water prevents drying out
- lots of gametes produced to inc the chances of fert
- eggs secrete chemicals to attract the sperm
7
Q
what happens after ext fert
A
- zygote develops into a larva that lives on a yolk or plankton = parents do not need to expend any energy into feeding the young
- env factors such as predators reduce the probability of offspring survival
- offspring are dispersed by currents, settle in diff areas, minimize competition
8
Q
internal fertilization
A
- inside female’s body
- does not require water, fewer gametes produced as poss of fert is much higher
- during mating the sperm is released directly into the female’s body and the sperm swims to egg for fert
9
Q
inc chances of survival in int fert
A
- in reptiles & birds, the embryo is nourished by yolk and protected by shell
- in mammals the developing embryo remains inside the female where it receives protection & nutrition
10
Q
ovipary
A
embryo develops in an egg outside the female’s body and is surrounded by a jelly like layer
11
Q
oviparous aquatic animals
A
- fish and amphibians
- fert takes place ext in water
- lots of gametes prod
- egg has v little yolk, less energy
12
Q
oviparous terrestrial animals
A
- mammals, birds
- int fert
- developing embryo is surrounded by a shell that protects it from dehydration
- large yolk, more energy
13
Q
ovovivipary
A
- sharks, lizards, snakes
- int fert, embryo surrounded by thin membranous shell inside female body, rec nutrition from yolk
- embryo hatches inside body and the young are born live
- in some species, eggs laid and embryos hatch almost immediately
- protected inside female
14
Q
vivipary
A
- int fert, fert egg develops into embryo w out the shell
- embryo/foetus directly connected to mother and receives nutrients through the placenta
- parental care requires lots of energy
15
Q
amniotic eggs
A
- prevents dehydration of the embryo and provides it with nutrients water and oxygen
- adapted for terrestrial life
