What substance is a reactant, along with oxygen, in cellular respiration?

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

Identify the structures ! 20 points

Science which of the following is an example of a cyclic behavior that is seasonal? i think the answer is d, i just need to double check : ). a. running from predators. b. searching for water. c. hunting at night. d. migrating for warmth. ***