Biology IGCSE Topic 9.1

What is the main function of the circulatory system?

• • A) To regulate body temperature

• • B) To transport blood and nutrients throughout the body

• • C) To produce hormones

• • D) To support muscle movement

Which of the following statements about the circulatory systems of fish and mammals is correct?

• A) Both fish and mammals have a four-chambered heart

• • B) Fish have a four-chambered heart, while mammals have a two-chambered heart.

• • C) Fish have a two-chambered heart and single circulation, while mammals have a four-chambered heart and double circulation.

• • D) Fish have a single circulation, while mammals have a single circulation.

What is the structure of the mammalian heart?

• • A) Two chambers: atrium and ventricle

• • B) Three chambers: two atria and one ventricle

• • C) Four chambers: two atria and two ventricles

• • D) Five chambers: three atria and two ventricles

How can the activity of the heart be monitored?

• • A) By measuring body temperature

• • B) By using an electrocardiogram (ECG)

• • C) By checking blood pressure

• • D) By monitoring brain waves

What is coronary heart disease primarily caused by?

• • A) High blood sugar levels

• • B) Blockage of coronary arteries by fatty deposits

• • C) Inflammation of the heart muscle

• • D) Abnormal heart rhythms

Which blood vessels carry blood away from the heart?

• • A) Veins

• • B) Capillaries

• • C) Arteries

• • D) Venules

What are platelets primarily responsible for in the blood?

• • A) Transporting oxygen

• • B) Blood clotting

• • C) Fighting infection

• • D) Carrying nutrients

What is the main function of red blood cells?

• • A) Producing antibodies

• • B) Fighting infection

• • C) Transporting oxygen

• • D) Promoting blood clotting

Which blood vessel type has the thickest muscular walls to withstand high pressure?

• • A) Arteries

• • B) Veins

• • C) Capillaries

• • D) Venules

What is the primary function of white blood cells?

• • A) Carrying oxygen

• • B) Clotting blood

• • C) Fighting infection

• • D) Transporting nutrients