Term
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Definition
budding:new individuals form as outgrowths from the body of another individual
-form by mitosis
-genetically identical to parent |
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Term
regeneration
(asexual reproduction) |
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Definition
pieces of individuals are able to regenerate missing body parts
-sea stars (starfish) |
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Term
Parthenogensis
(asexual reproduction) |
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Definition
development of offspring from unfertilized eggs
Haploid-diploid method of sex determination is common in many social insects
-haploid become male
-diploid become female
sometimes requires sexual behavior even though fertilization does no occur |
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Term
what are the 3 main steps in sexual reproduction
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Definition
1)Gametogensis: formation of gametes
2)Mating:bringing gametes together
3)Fertilization:fusion of gametes |
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Term
Gametogensis
(sexual reproduction) |
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Definition
spermatogensis:male germ cells divide by mitosis to form spermatogonia and primary spermocites
meiosis1 forms 2 diploid secondary spermocytes
meiosis2 forms 4 haploid spermatids
-spermatids develop into sperm cells |
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Term
Oogensis
(gametogensis, sexual reproduction) |
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Definition
female germ cells divide by mitosis to form ogonia and primary oocytes
1)meiosis1 forms a secondary oocyte and a polar body
2)meiosis2 froms a haploid ootid and another polar body
-ootids develop into an ova and polar bodies degrade
*human oocytes remain dormant for 10 & 50 yrs (puberty & menopause)* |
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Term
Internalized fertilization
(mating, sexual reproduction) |
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Definition
adaption to terrestrial life
-sperm can only disperse thru liquid
-prevents desiccation of gametes
copulation:direct transfer of sperm thru physical joining of male and female genetalia
indirect sperm transfer:spermatophores |
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Term
External fertilization
(mating, sexual reproduction) |
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Definition
animals release their gametes into the environment
common in aquatic taxa that synchronize release of eggs & sperm into the water
-spawning |
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Term
Hermaphrodite
(mating, sexual reproduction) |
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Definition
individuals that produce both sperm & eggs
simultaneus hermaphrodites:male & female @ the same time
-earthworms
sequential hermaphrodites:may function as male or female at different times in life
-anemone fish |
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Term
Internal fertilization
(mating, sexual reproduction) |
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Definition
oviparous:eggs are released by the female & development is done external to mom's body
viviparous:fertilization of egg & development occur inside mom's body
ovoviviparous:fertilized eggs hatch & develop inside mom's body but are not connected to mom via placenta |
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Term
what are the steps of fertilization
(sexual reproduction) |
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Definition
sperm & egg recognize each other
sperm is activated
plasma membrane of sperm & egg fuse
egg blocks entry of more sperm
egg begins development
sperm & egg nuclei fuse |
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Term
semen production & delivery
(fertilization,sexual development) |
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Definition
semen contains a mixture of fluids in addition to sperm
sperm is produced in testies & mature in the epidiymis
mature sperm travel to the urethra through the vas deferens
semen vesicles prostate and bulborethral glands all produce seminal fluids |
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Term
what do female sex organs produce
(fertilization, sexual reproduction) |
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Definition
eggs.they also recieve sperm & nurture the embryo
-eggs mature in the ovaries, then are released
-eggs travel thru the oviduct to the uterus
-fertilization happens in the oviduct
-the blastocyst implants in the endometrium of the wall of the uterus
-cirvex remains closed until birth |
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Term
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Definition
begins immediately after fertilization
-sperm contributes little more than DNA
-egg contributes most of the cytoplasm
-entry of the sperm into the egg rearranges the cytoplasm |
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Term
vegetal hemisphere
(development) |
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Definition
lower half of the egg that has nutrients that gravity has pulled there |
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Term
animal hemisphere
(development) |
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Definition
upper half of the egg contains the egg nucleus
when sperm enters the egg, bilateral symmetry is imposed by the formation of an anterior/posterior axis |
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Term
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Definition
process by which signal molecules cause changes in nearby cells
cells in the 3 germ layers act on each other thru induction to form organs and organ systems
signal molecules regulate gene activity, control development of notochord, body segmentation, organs, etc... |
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