1. Needed? Notes on oviparous etc. Scanned transparency diagram
Picture of Bird w/eggs and nest
Picture of Reptile w/eggs
Development of a chick embryo pictures
Bring out chick embryo specimens
Alligator holding eggs in mouth

2. The Amniotic Egg Section 20-4
Materials needed: The xerox of the amniotic egg. Students actually write answers to the questions on the back.
Xerox – review 20-4
Chicken embryo specimens.

3. Invasion of the land….
Amniotic eggs were an important adaptation to the survival of land animals.

4. Amniotic Egg The embryo develops in the amnion.
Reptiles have a leathery shell.
The embryo excretes waste into the allantois.
The yolk is the main food supply for the embryo.
Carbon dioxide and oxygen move freely through the shell.

5. #6 Amnion - encloses embryo in a protective pool of fluid.
Allantois surrounds blood vessels and provides a place for waste.
Chorion surrounds and protects everything.
The yolk sac (unlabelled) surrounds the yolk.

6. #7 Shell - prevents water loss Albumin - protein that cushions the egg
Amnion - provides a water environment
Yolk - provides food internally for embryo
Allantois - place for waste, respiration

7. Xerox 20-4
11 b
12 a
13 a
14 d
1 f
2 a
3 d
4 b
5 c
6 g
7 b
8 e
9 a
10 g

8. #15

9. #16 Water…... provides a solvent for waste
A cushioning material for protection.
A solvent for oxygen and carbon dioxide.