Why do birds migrate? What is the state of an animal similar to hibernation in hot and dry areas called as?

Which system revise and send electrical signals throughout the body

Explain two reasons you think it is important for scientists to search for new ways to treat cancer

Select the correct answer. which term do biologists use to describe the average number of individuals of a species per unit area? a. carrying capacity b. population density c. minimal viable population d. survivability curve