2. Today and tomorrow Today – finishing objectives (except 11)
Review Objectives
Tomorrow – project work

3. Compare and Contrast ‘Placentals’, monotremes and marsupials
Oviparous, ‘ovoviviparous’, viviparous
Precocial and altricial

4. Anamniotic Egg Jelly Layer Membrane Perivitelline fluid Yolk Plug
Embryo

5. Amniotic Egg

7. Placenta forms
from the Chorion

8. Amphibians = two lives Larval and adult stage
Anamniotic egg
External fertilization
Internal fertilization
“Copulation”
No ‘copulation’
No parental care to mouth brooding, skin brooding and ‘skin feeding’

10. Salamanders

11. Frogs
Amplexus

12. Snakes and Lizards Amniotic Egg Internal Fertilization Most Oviparous
Some ‘viviparous’
Sperm storage => delayed fertilization
Little (No) parental care

13. Snakes and Lizards
Viviparous- vipers (yes, that’s where the name comes from), boas and pythons, garter snakes
Within genus Sceloporous – all egg layers except one

14. Snakes and Lizards
Males have hemipenes

15. Snakes and Lizards
Couldn’t find a good image of female snake’s reprod system
Most lizards and snakes look very similar.

16. Snakes and Lizards

17. Snakes and Lizards
Couldn’t find a good image of female snake’s reprod system
Most lizards and snakes look very similar.
Male and Female reprod systems vary greatly depending on ‘season’

18. Birds Males of most birds have no copulatory organ
Cloaca to cloaca sperm transfer
Sperm storage in some species
‘Mating Flights’ are courtship
No known copulation during flight. I just wouldn’t work
Precocial and altricial
Parental care

20. Infundibulum – site of fertilization
Magnum – addition of albumin
Isthmus – addition of membrane
Uterus – shell and color

21. Sex Determination Humans and other mammals XY/XX
Most birds and snakes ZZ/WZ
Amphibians XY/XX or ZZ/WZ (sometimes within the same species!)
One bird is temperature-influenced (many reptiles)
Global climate change (all one sex)
Some birds and insects – hormone-dependent
Fertilized vs non-fertilized (haplodiploidy)
Sex-determination gene
Some lizards are all female

22. Quiz What happens to ensure only one sperm fertilizes an egg?
We went over hormonal control of the female reproductive cycle. Can a woman become pregnant (again) if she’s already pregnant? Explain.
What are the costs and benefits to semelparity and iteroparity?
Describe the ‘stages’ and locations of spermatogenesis and sperm maturation.

23. Homework