In which part of the human respiratory system does actual oxygen exchange take place?

A.

bronchi

B.

trachea

C.

diaphragm

D.

alveoli

How much energy is available at the third trophic level of the first trophic level has 300 000 kilometers of available energy and the loss rate between trophic levels is 90%?

What term defines varieties or populations of human beings distinguished by physical traits such as hair, eyes, skin color, and body shape? a. class b. cohort c. ethnicity d. race

Once an environmental bill becomes a law, who is usually responsible for the enforcement? a regulatory agency citizens a legislature the president or prime minister

Why do the symptoms of certain viral infections occur after having disappeared for a period of time?

A go cart with a mass of 200 is pushed with a force of 1000 N (1000 kg m/s^2). What is the acceleration of the go cart in m/s^2?

Compare and contrast a plant cell with an animal cell. Make sure you give at least two comparisons and two differences.

Explain why a cell needs to break down atp

Was the cutlass a pony car or muscle car

What type of selection favors the average individuals in a population

Which of the following ideal criteria for elimination of a disease is addressed by the following statement: Hepatitis B may establish a chronic infection that can lead to transmission of the disease even in the absence of symptoms? A.