animals

Question 1

1. fishes (paleozoic era 440 million yrs ago)

Answer 1

first vertebrae->initially cartilaginous(cartilage bones)-> then bony fishes
ectothermic(cold blooded)
-> body temp depends on environment

Question 2

2. Amphibians(paleozoic 370 million yrs ago)

Answer 2

evolved from fish
First vertebrae on land-> developed lungs, limbs & circulatory system
- reproduction dependant on water-external fertilization
- skin wet to survive: absorb O2
- ectothermic

Question 3

3. Reptiles (Paleozoic 300 million yrs ago)

Answer 3

evolved from amphibians - fully adapted to land
- dry scaly skin -> withstand drought
- advanced circulatory system
-internal fertilization: eggs
ectothermic

Question 4

4. Mammals (mesozoic 200 mil yrs ago)

Answer 4

-features for nurturing offspring & temp regulation
-TYPES: monotremes(egg) , marsupials( pouch for offspring) Placental mammals( develop offspring internally)
- Homeothermic (warm-blooded aka consistent body temp)
- breastfeeding glands & internal fertilization
- complex nervous system and advanced brain

Question 5

Birds ( mesozoic 150mil yrs ago)

Answer 5

evolved from small predatory dinosaurs
homeothermic
key adaptations: feathers & wings for flight
- internal fertilization (egg)