sexual reproduction Flashcards
what are gametes?
are special cells produced by the process of meiosis which in humans are sperm and egg
requires?
two parents
what must both parents have?
supply a gamete for fertilization
example of sexual reproduction
a great white could not mate with a make shark to produce an offspring
why couldnt a great white could not mate with a make shark to produce an offspring
size difference, speed difference and generally two different species
what is mating?
pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction.
what happens in mating?
many species have a set time in which they try to concieve in order to have their offspring in the spring
why can mating be difficult?
for species low in number or who live in large environments its sometimes difficult
three advantages of sexual reproduction?
- produces genetic variation
- the species can adapt to new environments
- genetic diversity
three disadvantages of sexual reproduction?
- time and energy
- fewer offspring at a time
- death can come to the offspring-many die from disease or disabilities
conditions of fertilization?
- nutrients for the embryo
- warm enough temperature
- moisture
- protection
-does not garuntee-
what are the methods of fertilization?
external fertilization
internal fertilization
pollination
pollen transport
what is external fertilization?
the egg and sperm cell combine into one outside the body; usually by species in the ocean
example of external fertilization?
spawning salmon
advantages and disadvantages of external fertilization?
advantage:
little energy
lots of offspring
disadvantage:
low survival
no parental care
what is internal reproduction?
sperm is deposited inside the female in order to fertilize the egg: more common in land animals; the embryo developes inside the mother until birth ex dogs
advantages and disadvantages of internal fertilization?
advantage: parental care
higher survival
disadvantage:
more energy
fewer zygotes produced
what is pollination?
pollen is transferred from the male portion of the flowering plant to the female reproductive portion
advantages and disadvantages of pollination?
advantage:
self polinate or cross polinate by wind
disadvantage:
requires insects like bees
what is pollen transport?
where non-flowering plants release pollen to the wind; cone barring
advantages and disadvantages of pollen transport
advantage:
genetic variation
not indegestible
disadvantage:
requires the wind
what are zygotes?
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
