A low level of CO2 encourages which response in stomata?
Correct answer B. Opening
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Biology MCQs
Page 23 of Biology multiple-choice questions with answers. Tap an option to check yourself.
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How many hypotheses are commonly proposed to explain the opening and closing of stomata?
Correct answer D. Two
What directly controls the opening and closing of stomata?
Correct answer B. Light
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Who put forward the pressure flow theory?
Correct answer D. Ernst Münch
Which of the following can be found in an open circulatory system?
Correct answer C. White Blood Cells
About 95% of the cytoplasm of red blood cells consists of which substance?
Correct answer C. Haemoglobin
Which white blood cells develop into macrophages that engulf larger particles by phagocytosis?
Correct answer D. Monocytes
Which structures act as multisensory hydraulic valves in plants?
Correct answer B. Guard cells
What share of total transpiration takes place through the stomata?
Correct answer C. 90%
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What is the pressure produced by the active secretion of salts and other solutes into the xylem sap called?
Correct answer C. Root pressure
What is the upward pull of water and dissolved minerals through the xylem towards the leaves called?
Correct answer A. Transpiration pull
What is it called when minerals pass from the soil into root epidermal cells through carrier proteins, moving down their concentration gradient?
Correct answer C. Facilitated diffusion
What do lenticels look like?
Correct answer C. Scars or small protrusions
What are the openings in bark, through which gases are exchanged and water vapour is lost, called?
Correct answer B. Lenticels
Which of the following are proteins?
Correct answer D. All of these
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Cooley’s anaemia is another name for which disorder?
Correct answer C. Thalassaemia
Where is the tricuspid valve located?
Correct answer C. Between right atrium and right ventricle
What does the QRS complex on an ECG represent?
Correct answer B. Ventricular systole
Which of the following blood vessels have the thickest walls?
Correct answer C. Arteries
What term describes the force with which blood pushes against the walls of blood vessels?
Correct answer B. Blood pressure