Reproductive Physiology Flashcards
1
Q
Semelparity
A
Organisms reproduce only once in their whole life
2
Q
Iteroparity
A
multiple reproductive cycles over a lifetime
3
Q
Errantia: Reproduction
A
- No permanent sex organs; separate sexes
- Neurohormone represses sexual organs until changes in the photoperiod.
- Gonads appear as simple temporary swellings.
- Gametes are shed into coelom and exit by gonoducts, nephridia, or rupturing of the body (death)
- Fertilization is external
4
Q
Errantia Reproduction: Atokes and Epitokes
A
- Anterior segments make up sexually unripe worms called atokes
- Occur in this form most of the year
- Epitokal region consists of segments packed with gametes * Form around swarming time
5
Q
Palolo Worms
A
- Live in burrows in coral in the South Seas
- During swarming period, epitokes break off and swim to the surface
- Atoke remains in burrow and can form epitoke again
- Epitokes burst before sunrise, freeing eggs and sperm
6
Q
Embryonic diapause:
A
- programmed state of arrest or slowed development synchronized with favorable seasonal environmental conditions
7
Q
Lamprey Reproduction
A
- Larvae filter feed for 3 to 7 years, then metamorphose into adults
- don’t feed after metamorphosis
- Ascend freshwater streams to breed
- As eggs are shed into nest, the male fertilizes them
- Adults die soon after spawning
- digestive tract degenerates as adult.
8
Q
Sequential hermaphrodism
A
- Change from egg producers to sperm producers (or vice versa)
- Fish, molluscs, annelid ocean worms
- Hypothetical reason: small fish cannot control a harem; may be reproductively beneficial to produce eggs first.
- Behaviour and appearance may change
9
Q
Temperature dependent sex determination
A
Galápagos Tortoises
Oviparous
Fertilization is internal
Bury their eggs in the ground
* Low temperatures produce males
* High temperatures produce females
10
Q
Crocodilian Reproduction
A
- Crocodilians are oviparous
- Crocodilians provide extensive parental care.
- Mothers respond to vocalizations from hatching young.
- Young are guarded by mother for 2 years or more.
