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 23 of 35
- A. Transport saturation
- B. Uphill transport
- C. Requirement of special membrane proteins
- D. High selectivity
Explanation: Facilitated transport is the process of spontaneous passive transport or downhill transport of molecules or ions across a biological…
Correct answer: Uphill transport- A. Cytoskeleton
- B. Mitochondria
- C. Endoplasmic reticulum
- D. Chloroplasts
Explanation: The leaf and stem epidermis is covered with pores called stomata (sing., stoma), part of a stoma complex consisting of a pore surrounded…
Correct answer: Chloroplasts- A. Weak gravitational pull
- B. Transpiration pull
- C. Lignified thick walls
- D. Cohesion and adhesion
Explanation: The transpiration process, pulls water upwards with the help of cohesion and adhesion properties of water molecules.
Correct answer: Cohesion and adhesion- A. No movement of water
- B. Equilibrium between the two
- C. Movement of water from cell A to B
- D. Movement of water from cell B to A
Explanation: Diffusion pressure deficit is the reduction in the diffusion pressure of water in a system over its pure state.
Correct answer: Movement of water from cell A to B- A. Osmotic pressure
- B. Amount of water absorbed equals the amount transpired
- C. Root pressure
- D. Potential difference between the tip of the tube and that of the plant
Explanation: Potometer is an instrument or apparatus with the help of which, rate of transpiration can be measured.
Correct answer: Amount of water absorbed equals the amount transpired- A. Transpiration
- B. Guttation
- C. Gaseous exchange
- D. Bleeding
Explanation: Lenticels generally appear under stomata. The lenticel of phellogen itself also has intercellular spaces.
Correct answer: Gaseous exchange- A. Temperature
- B. Temperature and metabolic inhibitor
- C. Metabolic inhibitor
- D. Humidity
Explanation: Rate of salt absorption increases when temperature increases but to a certain limit as salt absorption is inhibited at higher temperature…
Correct answer: Temperature and metabolic inhibitor- A. Presence of oxygen
- B. Low CO2 concentration
- C. High CO2 concentration
- D. CO2 absent
Explanation: Zelitch (1963) suggested that glycolic acid is formed in the guard cells. This acid is formed under a low concentration of CO.
Correct answer: Low CO2 concentration- A. Increase of sugar in phloem
- B. Elongation of phloem cell
- C. Separation of phloem parenchyma
- D. Strengthening of phloem fiber.
Explanation: When the phloem cells, just near the source, for example, green leaves attain a higher concentration of sugars, it is called the process…
Correct answer: Increase of sugar in phloem- A. Active transport
- B. Osmosis
- C. Diffusion
- D. All of the above
Explanation: Active transport involves the movement of materials across the membrane against the concentration gradient of the solute particles.
Correct answer: Active transport- A. Gravitational water
- B. Chemically bound water
- C. Capillary water
- D. Hygroscopic water
Explanation: Capillary water refers to the water in soil that is held between soil particles by capillary forces and is available for plant roots to…
Correct answer: Capillary water- A. 100 and 200
- B. zero and 100
- C. 100 and zero
- D. zero and zero
Explanation: Water potential of pure water is always 0, as it is the reference point for comparison.
Correct answer: zero and 100- A. Turgor pressure
- B. Water potential
- C. Wall pressure
- D. Osmotic pressure
Explanation: Water potential becomes zero when the cell is fully turgid, indicating equilibrium between the water inside and outside the cell.
Correct answer: Water potential- A. Fluctuate
- B. Remain unchanged
- C. Increase
- D. Decrease
Explanation: When the turgidity of a cell increases, it means that the cell's central vacuole is filled with more water, exerting an increased pressure…
Correct answer: Increase- A. Parenchyma
- B. Cambium
- C. Xylem
- D. Phloem
Explanation: Bidirectional translocation of solutes takes place in the phloem. The phloem is responsible for transporting organic compounds, such as…
Correct answer: Phloem- A. Osmosis
- B. Passive absorption
- C. Endocytosis
- D. Active absorption
Explanation: When water enters roots due to diffusion, it is termed as passive absorption.
Correct answer: Passive absorption- A. Accumulation of inorganic salts in the cells
- B. Accumulation of organic compounds in the cells
- C. Water potential gradient
- D. Chemical potential gradient
Explanation: Water moves from one cell of the cortex to an adjacent one in the roots due to the difference in water potential between the cells.
Correct answer: Water potential gradient- A. Glucose
- B. Maltose
- C. Starch
- D. Sucrose
Explanation: Sucrose is the main form of translocated carbohydrate nutrient in plants.
Correct answer: Sucrose- A. Closes completely
- B. Opens partially
- C. Opens fully
- D. Remains unchanged
Explanation: When sugar is converted into starch in guard cells, the stomatal pore closes completely.
Correct answer: Closes completely- A. Sea level
- B. 1 km below sea level
- C. 1 km above sea level
- D. 1.5 km above sea level
Explanation: At constant temperature, the rate of transpiration will be higher at 1.5 km above the sea level.
Correct answer: 1.5 km above sea level