The brain and spinal cord are part of the nervous system.
The electrical charges that act as nervous signals are called .
Jellyfish do not have a brain. Instead their nervous system is called a .
After nervous systems began to develop in bilaterally symmetric animals, some developed ventral, or front, nerve cords, while chordates developed nerve cords.
Skeletons that allow for movement by using muscles and squeezing liquid to change the body shape are called skeletons.
do not grow with arthropods, and so occasionally must be shed and regrown from chitin.
Muscles move endo- and exoskeletons by .
is the joining of two gametes called sperm and egg.
A fish that lays her eggs in a cluster is initiating fertilization.
are an adaptation by reptiles to allow for reproduction and embryo development on land.
Describe three different strategies used by three different animals to thermoregulate.
If you see a snake coiled up in a sunny patch of grass, what can you probably conclude about the type of thermoregulator it is. Why?