Grade 9 Science Quiz: Circulatory System

Which organ pumps blood throughout the body?

• Lungs

• Heart

• Liver

• Kidney

What is the function of red blood cells?

• Fight infection

• Transport oxygen

• Clot blood

• Filter toxins

Which blood vessel carries blood away from the heart?

• Veins

• Capillaries

• Arteries

• Venules

What is the main function of white blood cells?

• Carry oxygen

• Fight diseases

• Transport nutrients

• Regulate temperature

What part of the heart receives oxygen-poor blood from the body?

• Left ventricle

• Right atrium

• Right ventricle

• Left atrium

Which chamber of the heart pumps oxygen-rich blood to the rest of the body?

• Right atrium

• Right ventricle

• Left atrium

• Left ventricle

Which component of blood is responsible for clotting?

• Plasma

• White blood cells

• Red blood cells

• Platelets

What is the role of hemoglobin?

• Digest proteins

• Filter toxins

• Transport oxygen

• Destroy bacteria

Which heart valve prevents the backflow of blood between the left atrium and ventricle?

• Aortic valve

• Tricuspid valve

• Pulmonary valve

• Mitral valve

What structure divides the heart into left and right sides?

• Atrium

• Valve

• Septum

• Aorta