rev tt tansport sh1

What is the main job of the heart?

• To pump blood around the body.

• To send food to the small intestines.

• To break down food.

• To give energy to the body.

______________ are the smallest blood vessels.

• Arteries
• Veins
• Capillaries

What type of cells are the body's defenders against infection?

• Leucocytes

• Erythrocytes

• Blastocytes

• Plasmacytes

Which of the following plays a crucial role in the life-saving process of clotting blood?

• Phagocytes

• Leucocytes

• Erythrocytes

• Platelets

Which of the following statements about oxygen combining with haemoglobin is true?

• All oxygen molecules that combine stop the haemoglobin molecule from changing shape.

• Each haem group can combine with four oxygen molecules.

• The first oxygen molecule that combines does not affect the shape of haemoglobin.

• It becomes easier for the third oxygen molecule to combine after the second one has combined.

The diagram below shows the front view of a human heart.

Letters P, Q, R and S indicate the different chambers of the heart.

What is the correct sequence in which a blood cell returning from other parts of the body passes through the four chambers of the heart?

• R-S-P-Q

• Q-S-R-P

• P-R-Q-S

• S-R-P-Q

Which chamber of the heart has the thickest walls?

• left atrium

• left ventricle

• right atrium

• right ventricle

Which substances are dissolved in human blood plasma?

• carbon dioxide, haemoglobin and glucose

• carbon dioxide, oxygen and haemoglobin

• glucose, hormones and urea

• oxygen, urea and starch

Which blood vessel has a high carbon dioxide concentration, a low oxygen concentration and a high blood pressure?

• aorta

• pulmonary artery

• pulmonary vein

• vena cava

In the Bohr effect, what cause the curve shift to the right?

• decreases haemoglobin affinity for oxygen.

• increased concentration of carbon dioxide

• low pH

• all correct