2 Rabbit skeleton: only 8% of a rabbit's body mass
3 Lamb
4 Ostrich skeleton
5 Lamb innards: 4 stomachs
6 Reindeer: antlers are re-generated annually
7 Goat: the first animal domesticated by humans
8 Sheep: domesticated sheep often lack horns
9 Horse: walks on a single (hoofed) toe
10 Horse's head: ears can rotate 180 degrees; the large nose can detect minute odors but blocks the forward view
11 Cat
12 Cat's heart and lungs
13 Dog: blood vessels
14 Bull: cows obtain nutrients to build large muscles by regurgitating food and chewing "cud"
15 Comparitive hearts of various species: generally, the bigger the heart, the bigger the animal; mammals and birds have 4 chambers, reptiles/amphibians 3, and fish 2
16 Giraffe: same number of vertebrae as human (7) but much taller, with long neck enabling it to reach tall trees
