Which of these substances would diffuse into a human cell?
Oxygen
Carbon dioxide
Urea
Which organ system is involved in providing the bloodstream with glucose?
Gaseous exchange
Circulatory system
Digestive system
Which organ filters urea out of the blood?
Liver
Kidneys
Bladder
Which component of blood transports oxygen?
Plasma
Platelets
Red blood cells
What does a partially permeable membrane mean?
All substances can cross the membrane
No substances can cross the membrane
Only certain substances can cross the membrane
Which of these animals would have the smallest surface area to volume ratio?
Elephant
Mouse
Mosquito
What is the name of the blood vessel that takes blood from the heart to the lungs?
Pulmonary artery
Aorta
Vena cava
What is the surface area to volume ratio if a multicellular organism has a surface area of 200 cm2 and a volume of 500 cm3 ?
2:5
5:2
250:100
What is active transport?
The net movement of molecules from a high concentration to a low concentration
The net movement of water molecules from a high concentration to a low concentration across a partially permeable membrane
The net movement of molecules from a low concentration to a high concentration, using energy
Why do veins and the heart have valves?
To resist high pressure
To prevent backflow of blood
To resist low pressure