A. Adaptations: enabled them to live their entire life without water.
1) lungs – most have 2 but snakes have 1 which fits neatly into its slender body
* How canthey breathe while eating then??
a special tube in the mouth that extends outside the snake’s mouth while swallowing so doesn’t suffocate
2) scaly skin
a. dry and leathery
b. advantage: helps prevent loss of water in dry environment
3) toes, claws, suction cups – help climb and dig (some are legless Ex. snakes)
4) amniotic egg
a. do not need water for development
b. creates a protected environment for the embryo
c. parts:
1. Amnion – membrane enclosing the salty fluid in which the embryo floats
2. Yolk Sac – encloses the yolk which is rich in nutrients and nourishes the embryo
3. Allantois – stores waste
4. Chorion – lines the outer shell, encloses the embryo and other membranes – also aids in gas exchange between egg and outside environment
5. Leathery Shell – waterproof but porous