In which organism does the respiratory system bring air directly near all the body's cells so that the circulatory system is not a main transporter of oxygen to the cells? a. tree frog b. mosquito c. shark d. lion

Which hormone is used by both males and female?

What is the most important inorganic material for livings things? ! due tomorrow!

Viruses can be transmitted through air, water, food, insect bites, and direct skin contact. once a virus gains entry into the body, it invades a host cell in order to? a. synthesize antibodies for defense b. deactivate the host cell's defenses c. access cell processes for reproduction d. metabolize host proteins and grow