key terms
a thick walled muscular part of a bird's stomach.
what is a gizzard
an egg laying mammal
what are montremes.
the system that coordinates the animal's movements
what is the nervouse system
a group of vertebrates with about 4000 different species.
what are mammals
a "storage tank" for a bird.
what is a crop
a combined action of rib and large muscle
what is a diaphram
an organ in the female mammal that passes materials between the mother and the developing embryo.
what is the placenta
makes up 8% of mammals
what are primates
feather that acts as an insulator
what is a down feather
the organ that produces milk for the offspring.
what is the mammary gland.
a mammal that developes inside the mothers belly until its body systems can function independantly.
what is a placenta mammal
makes up 38% of mammals
what are rodents
a large feather that gives shape to a birds body
contour feather
a group of animals that has fur and has the human as an example.
what is a mammal.
the lengt of time between fertilization and birth
what is the gestation period
an insulator that isn't made of hair
what is the layer of fat beneath the skil of a mammal
an endothermic vertebrate that lays eggs, has feathers, and a four chambered heart.
what is a bird
the difference in pressure above and below the wings as the bird moves through the air produces an upward force which causes the bird to rise.
what is lift
mammals whos young are born at an early stage of developement
what are marsupials
an insulator made of hair
what is fur