Animal Reproduction Flashcards
How do animals reproduce?
Both sexually (meiosis) and asexually (mitosis)
Can animal species switch between both asexual and sexual reproduction or are they stuck in one form? if so what are three influencing factors?
yes they can.
- environmental cues
- changes in population density
- seasonal
what are the three main mechanisms of asexual reproduction?
- budding
- fission
- pathenogenesis
What is gametogenesis
gametogenesis is the mechanism of sexual reproduction
what is spermatogenesis
spermogenesis is the formation of sperm
what is oogenesis
oogenesis is the formation of eggs
what are the steps from a primoridial germ cell during their development to a mature sperm/egg
primordial germ cell > gonia > cyte > tid > mature gametes
lecture 7 page 2 slide 5 (NEED TO KNOW)
what are sertoli cells
sertoli cells are large cells in seminiferous tubular walls
what are leydig cells
leydig cells are located in the testis among seminiferous tubules
what are the two cells that contribute to gametogenesis in males
sertoli cells and leydig cells
What are the important characteristics of living organisms
the important characteristics of living organisms is the ability to produce others of their own kind
what is asexual reproduction
Asexual reproduction is based on mitosis and results
in offspring that are genetically identical to one
another and to their parent
what is sexual reproduction
Sexual reproduction is based on meiosis and fusion of haploid (1n) gametes to form a diploid (2n) zygote
what is budding
an offspring begins to form within or on a parent; the process is completed when the offspring breaks free and begins to grow on its own. The offspring is a miniature version of the parent.
does budding occur in vertebrates and/or invertebrates
it only occurs in invertebrates
what is fission
an individual simply splits into two or more
descendants.
does fission occur in vertebrates and/or invertebrates
it only occurs in invertebrates
what is parthenogenesis
female offspring develop from
unfertilised eggs. These offspring are genetically
identical to the mother.
does sexual reproduction produce genetically variable offspring
yes
what are three special characteristics of sperm cells
- nucleus
- chromosomes
- acrosome
what is capacitation
.
sperm must stay in the female tract
for a period of time before fertilisation of the egg
can take place
what reproductive hormones to follicle cells produce
- steroid
- estrogen
- preovulatory hormone
what is fertilisation
fertilisation is the joining of a sperm and an egg to form a
diploid zygote.
what is external fertilisation
external fertilisation occurs in many species when individuals release their gametes into their environment
what is internal fertilisation
internal fertilisation occurs in the vast majority of terrestrial animals and a significant number of aquatic animals where males deposit sperm into the reproductive tracts of females and fertilisation occurs.
what are the two ways in which fertilisation occurs
coppulation and spermatophore
what is oviparous? give an example of it.
Oviparous animals, the egg is laid outside the
mother’s body and the embryo develops in the
external environment.
turtles
what is viviparous? give an example of it.
Viviparous species, the egg remains within the
mother’s body. There the embryo develops and
receives nutrition directly from the mother.
humans
what is ovoviviparity? give an example of it.
Ovoviviparity, offspring develop inside the
mother’s body but are nourished by nutrient-rich
yolk stored in the egg.
sharks
what is the structure of a mature egg from outside to in?
jelly coat > vitelline membrane > plasma membrane > cortical granule > egg cytoplasm
lecture 7 page 8 slide 2
