What do scientists call regions of earth that contain an unusually large number of species that are threatened by habitat loss?

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

Which part of the neuron below is indicated by the arrow, and what is its function? hormones send chemical signals throughout the body to regulate other body processes. hormones are chemical signals that are sent throughout the body to regulate other body processes. hormones send electrical signals throughout the body to regulate other body processes. hormones are electrical signals that are sent throughout the body to regulate other body processes.

Describe characteristics of a good respitory surface