Which of the following statements is/are true of hormones?

Exercising and working muscles, as athletes do, causes:

The rise and fall of hormone levels in the body is an example of:

Most cells are microscopic because at this small size, __________.

The __________ system and the __________ system work together to coordinate and control physiological processes in most animals.

Which of the following is a characteristic of the nervous system but not the endocrine system?

Which of the following best illustrates homeostasis?

Which of the following is a function of your circadian rhythm?

When a jogger starts to run, the rate at which his muscles produce CO₂ rises sharply. But the CO₂ in his blood rises only slightly before he starts to breathe faster and his heart starts beating stronger. Soon his increased rate of CO₂ production is balanced by an increased rate of CO₂ removal. This would be an example of __________ feedback because the jogger's circulatory and respiratory systems are __________.