Chapter 15: Body Fluids and Circulation — Online MCQ Test
BIOLOGY · CLASS 11 FIRST PUC · Karnataka State Board
Practice Chapter 15: Body Fluids and Circulation with a free chapter-wise online MCQ test.
This chapter covers: Blood Plasma Red Blood Cells White Blood Cells Platelets Lymph Heart Cardiac Cycle Blood Circulation Blood Pressure.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 15: Body Fluids and Circulation — Important Questions & Answers
Which component of blood is the fluid matrix in which blood cells are suspended?
- A. Serum
- B. Plasma
- C. Lymph
- D. Haemoglobin
Answer: B. Plasma
Plasma is the straw-coloured fluid part of blood that carries cells, proteins, nutrients, hormones, and wastes.
Plasma is the straw-coloured fluid part of blood that carries cells, proteins, nutrients, hormones, and wastes.
Which blood cells are mainly responsible for transport of oxygen?
- A. Platelets
- B. White blood cells
- C. Red blood cells
- D. Lymphocytes
Answer: C. Red blood cells
Red blood cells contain haemoglobin, which binds and transports oxygen.
Red blood cells contain haemoglobin, which binds and transports oxygen.
The average count of platelets per mm³ of blood in a normal healthy person is approximately:
- A. 1.5–3.5 lakh
- B. 5–6 million
- C. 5,000–10,000
- D. 2,000–3,000
Answer: A. 1.5–3.5 lakh
Platelets are normally present in large numbers, around 1.5–3.5 lakh per mm³ of blood.
Platelets are normally present in large numbers, around 1.5–3.5 lakh per mm³ of blood.
Which of the following is a major function of white blood cells?
- A. Transport of carbon dioxide
- B. Blood clotting
- C. Defence against infection
- D. Transport of glucose
Answer: C. Defence against infection
White blood cells protect the body by engulfing pathogens and producing immune responses.
White blood cells protect the body by engulfing pathogens and producing immune responses.
Which plasma protein is primarily involved in blood clotting?
- A. Albumin
- B. Globulin
- C. Fibrinogen
- D. Haemoglobin
Answer: C. Fibrinogen
Fibrinogen is converted into fibrin during clotting and helps form the clot.
Fibrinogen is converted into fibrin during clotting and helps form the clot.
Which of the following is NOT a function of plasma?
- A. Transport of nutrients
- B. Transport of hormones
- C. Transport of oxygen by haemoglobin
- D. Transport of wastes
Answer: C. Transport of oxygen by haemoglobin
Oxygen is mainly transported by haemoglobin in RBCs, not by plasma.
Oxygen is mainly transported by haemoglobin in RBCs, not by plasma.
A rise in heart rate and force of contraction is mainly associated with stimulation of the:
- A. Parasympathetic nervous system
- B. Sympathetic nervous system
- C. Central nervous system only
- D. Endocrine pancreas
Answer: B. Sympathetic nervous system
Sympathetic stimulation increases heart rate and the force of cardiac contraction.
Sympathetic stimulation increases heart rate and the force of cardiac contraction.
If the semilunar valves fail to close properly, the most likely result is:
- A. Backflow of blood from arteries into ventricles
- B. Backflow of blood from ventricles into atria
- C. No blood enters the ventricles
- D. No oxygen is carried in blood
Answer: A. Backflow of blood from arteries into ventricles
Semilunar valves prevent blood from flowing back from the aorta and pulmonary artery into the ventricles.
Semilunar valves prevent blood from flowing back from the aorta and pulmonary artery into the ventricles.
Which of the following is the correct explanation of why the left ventricle has a thicker wall than the right ventricle?
- A. It pumps blood to the lungs at low pressure
- B. It pumps blood to the entire body at higher pressure
- C. It receives deoxygenated blood from the body
- D. It stores oxygenated blood before circulation
Answer: B. It pumps blood to the entire body at higher pressure
The left ventricle pumps blood through systemic circulation, so it must generate greater pressure.
The left ventricle pumps blood through systemic circulation, so it must generate greater pressure.
A student says: 'Blood plasma and serum are the same.' Which is the most accurate correction?
- A. Correct, both are identical in all respects
- B. Incorrect, serum is plasma without clotting factors
- C. Incorrect, plasma is the solid part of blood
- D. Correct, because serum contains RBCs
Answer: B. Incorrect, serum is plasma without clotting factors
Serum is obtained after blood clotting and lacks clotting factors like fibrinogen, unlike plasma.
Serum is obtained after blood clotting and lacks clotting factors like fibrinogen, unlike plasma.