Free Circulation MCQs with Answers
695 Circulation MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The circulatory system covers the chambers, valves and conducting pathway of the human heart, along with the cardiac cycle and control of heartbeat. It compares arteries, veins and capillaries by structure and function, and explains how the lymphatic system returns tissue fluid, transports absorbed fats and supports immunity.
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Read the Circulation notesFree MDCAT chapter notes with key terms695 questions · page 12 of 35
- A. Red
- B. Blue
- C. Green
- D. Orange
Explanation: Exposure to blue light is effective in photosynthesis and plays a crucial role in the regulation of stomatal opening.
Correct answer: Blue- A. Globulin
- B. Prothrombin
- C. Fibrinogen
- D. Albumin
Explanation: Serum albumin is a protein found in blood plasma that helps maintain the osmotic pressure between the blood vessels and tissues.
Correct answer: Albumin- A. Move blood from semilunar valve into pulmonary vein
- B. Prevent the backward flow of blood from the ventricle
- C. Push the blood from right atrium to left atrium
- D. Push the blood from left atrium to aorta
Explanation: The papillary muscles are muscles located in the ventricles of the heart.
Correct answer: Prevent the backward flow of blood from the ventricle- A. Arterioles → metarterioles → capillaries → thoroughfare channels
- B. Arterioles → thoroughfare channel → metarterioles → capillaries
- C. Metarterioles → arterioles → thoroughfare channels → capillaries
Explanation: Explanation: Option B, C and D are incorrect because there is only one proper pathway for blood flow which is from…
Correct answer: Arterioles → metarterioles → capillaries → thoroughfare channels- A. Companion cell
- B. Fibres
- C. Sieve tubes
- D. Vessels
Explanation: Sieve tubes are elongated living cells of Phloem which are responsible for the transport of organic solutes, mostly sugars.
Correct answer: Sieve tubes- A. Femoral
- B. Renal
- C. Pulmonary
- D. lliac
Explanation: Pulmonary vein carries oxygenated blood from lungs to left atrium of heart.
Correct answer: Pulmonary- A. Neck region
- B. Axilla
- C. Groin
- D. Spleen
Explanation: Lymph nodes are present in neck region, axilla, and groin of humans. Lymph node is a mass of connective tissue.
Correct answer: Spleen- A. Whole leaf turned blue black
- B. Only B portion turned blue black
- C. Only A & B portions remained colourless and the rest of the leaf turned blue black
- D. Only A remained colourless and the rest of the leaf turned blue black
Explanation: The part of the destached leaf, when covered with black strip and exposed to sunlight it does not produce any starch because it cannot…
Correct answer: Only A remained colourless and the rest of the leaf turned blue black- A. Root pressure
- B. Imbibition
- C. Water potential
- D. Hydrogen bonding
Explanation: Hydrogen bonding prevents division of water molecules hence pulling it up using cohesion and adhesion
Correct answer: Hydrogen bonding- A. Epidermal cells
- B. Spongy mesophyll cells
- C. Guard cells
- D. Palisade mesophyll cells
Explanation: Guard cells, containing chloroplast, are a part of the leaf's epidermal layer ( the epidermis).
Correct answer: Guard cells- A. Water
- B. Solute
- C. Hydrostatic
- D. Hydrodynamic
Explanation: Hydrostatic pressure refers to the pressure that any fluid in a confined space exerts.
Correct answer: Hydrostatic- A. Atria of heart
- B. Ventricles of heart
- C. Arteries
- D. Veins
Explanation: Ventricular contraction ejects blood into the major arteries, resulting in a flow from regions of higher pressure to regions of lower…
Correct answer: Ventricles of heart233. SA node is located:
- A. Upper lateral wall of left atrium
- B. Lower lateral wall of left atrium
- C. Upper lateral wall of right atrium
- D. Lower lateral wall of right atrium
Explanation: It is located in the upper lateral wall of right atrium The upper lateral wall of the right atrium primarily contains the openings of the…
Correct answer: Upper lateral wall of right atrium- A. Artery
- B. Capillary
- C. Vein
- D. All of the above
Explanation: Unlike arteries, veins contain valves that ensure blood flows in one direction only.
Correct answer: Vein- A. Red Blood Cell
- B. White Blood Cell
- C. Plasma Cell
- D. Platelets
Explanation: White blood cells, mainly neutrophils, have a multi-lobed nucleus, which consists of three to five lobes connected by slender strands.
Correct answer: White Blood Cell- A. Lymph
- B. Plasma
- C. Blood
- D. Serum
Explanation: This fluid is derived from blood plasma as fluids pass through capillary walls at the arterial end.
Correct answer: Lymph- A. Thyroid
- B. Thymus
- C. Testes
- D. Bursa
Explanation: T- cells are so-called because they are predominantly produced in the thymus.
Correct answer: Thymus- A. Exposure of actual infection
- B. Injection of antiserum
- C. Injection of antibiotics
- D. Vaccination
Explanation: Artificial active immunity is acquired through the introduction of a killed or weakened form of the disease organism through vaccination
Correct answer: Vaccination- A. 6
- B. 1
- C. 3
- D. 4
- E. 5
Explanation: The left ventricle of the heart is located at position 6 in the figure.
Correct answer: 6- A. Red blood cells
- B. White blood cells
- C. Platelets
- D. Plasma
- E. Both A and C
Explanation: "White blood cells" (also known as leukocytes) are a crucial component of the immune system and are responsible for defending the body…
Correct answer: White blood cells