1. The part of the shaft below the vane of a bird feather is the
A. quill
B. barb
C. crop
D. papilla
4. Mammal hairs are filled with a protein called
A. melatonin
B. melanin
C. chlorophyll
D. keratin
2. What characteristic is unique to birds?
A. They can fly.
B. They have wings.
C. They have feathers.
D. They are endothermic.
5. (True or False) Umbilical cords are found only in placental mammals.
A. True
B. False
3. (True or False) The yolk in a bird egg is the food supply for the embryo.
A. True
B. False
6. Which group is the largest?
A. primates
B. marsupials
C. bats
D. rodents