B.5

Which of these substances would diffuse INTO a human cell?

• Oxygen

• Carbon dioxide

• Urea

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

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

Which organ system is involved in providing the bloodstream with glucose?

• Gaseous exchange

• Circulatory system

• Digestive system

Which organ system is involved in providing the bloodstream with oxygen?

• Gaseous exchange

• Circulatory system

• Digestive system

Which organ system is involved in transporting substances around the body in the blood?

• Gaseous exchange

• Circulatory system

• Digestive system