exam 3 wp pt 2 Flashcards
what are the derived characters of tetrapods? (4)
1) limbs with digits
2) head separated from body by a moveable neck
3) bones of pelvic girdle are fused to backbone
4) adults lack gills
what type of fertilization do amphibians use?
external, amplexus
what is pedomorphosis?
condition where organisms retain aquatic existence (axolotl)
what do amniotes include?
reptiles and mammals
what membranes do an amniotic egg contain?
amnion, chorion, allantois, albumen
what does the chorion do?
surrounds amnion and allows for gas exchange b/w embryo and air
what does the allantois do?
disposal sac for metabolic wastes produced by embryo
what does the albumen do?
hydrates embryo and provides protein (egg white)
what is the pastron of a turtle?
ventral portion that forms from bones of pectoral girdle and dermal bone
what are derived characters for birds that are adaptations for flight? (4)
1) no urinary bladder
2) one ovary
3) toothless
4) honeycombed bones
what is archaeopteryx?
most important fossil that have both reptile and bird characteristics
how is the archaeopteryx lineage significant?
marks divergence from reptiles to birds
what are the derived characters of mammals? (6)
1) mammary glands
2) keratinized hair
3) endothermic
4) larger brain
5) efficient resp/circulatory systems
6) differentiated teeth
relationship b/w mammals and reptiles
major modifications in the way the jaw articulates with the bone
what organisms are in the class monotremes?
platypus, echidna
what are etherians known as?
placental mammals, vivparous
what animals are true horns found on and how long do they grow?
only found on artiodactyls, grow throughout lifetime
