Biology

Biology Multiple Choice Questions and Answers (MCQ) PDF: Quizzes & Practice Tests with Answer Key. This section Biology basic concepts, theory and objective tests.

This section covers following topic MCQs: Bioenergetics, biological molecules, cell biology, coordination and control, enzymes, fungi, recyclers kingdom, gaseous exchange, growth and development, kingdom Animalia, kingdom plantae, kingdom prokaryotae, kingdom protoctista, nutrition, reproduction, support and movements, transport biology, variety of life, and homeostasis etc.

    Coordination and Control
    Which plant hormone promotes cell division and cell differentiation along with auxin?
    Cytokininspromote cell division, cell growth and differentiation along with auxin. Ethylene is responsible for fruit ripening. Abscisic acid helps the plant to sustain in adverse conditions. Gibberellins enable the plants to grow taller.
    Author: rikazzz Comment
    Homeostasis
    When blood sodium ion concentration moves close to the lower limit of normal (137 mmol/L), what would the body do to maintain homeostasis?
    Homeostasis almost always results in a response that opposes the detected change. Aldosterone promotes the reabsorption of Na+ from the filtrate; this would slow the decline in the blood’s sodium concentration. The other three choices are wrong.
    Author: rikazzz Comment
    Homeostasis
    As the osmotic concentration of blood increases, what homeostatic response would the body produce?
    Homeostasis tends to result in a response that opposes the detected change. So something would be done to reverse the rise in osmotic concentration of blood. Drinking water would do this. The other three choices would not oppose the rise in osmotic concentration.
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    Biology
    Plant harmones are also called
    Plant hormones (also known as phytohormones) are organic substances that regulate plant growth and development.
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    Homeostasis
    Some of the body’s homeostatic responses rely on “negative feedback”. Which of the following happens in negative feedback?
    “Negative” refers to the response being in the opposite direction to the stimulus. Thus if a variable is increasing, then the body’s response is to produce a change that causes the variable to decrease. The body does not “ignore” stimuli.
    Author: rikazzz Comment
    Biology
    Which of the following enzymes is present in the salivary glands of human beings?
    Saliva contains the enzyme amylase, also called ptyalin, which is capable of breaking down starch into simpler sugars such as maltose and dextrin that can be further broken down in the small intestine.
    Author: rikazzz Comment
    Biology
    Plants that have lost their capacity to reproduce seeds, usually reproduce by
    If the plants lose their capacity to produce seed, they will carry out reproduction through asexual means, through their vegetative parts like stem, leaf, branch, etc. The formation of new plants from detached vegetative parts is called vegetative propagation.
    Author: rikazzz Comment
    Coordination and Control
    Plant appears to bend towards light due to:
    Auxins are synthesized at the shoot tip and help the cells to grow longer. When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. This concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from light. Thus, the plant appears to bend towards light.
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    Cell Cycle
    Which of following is not phase of mitosis?
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    Homeostasis
    Which of the following would be a negative feedback response by the body to hyperthermia?
    Hyperthermia is an increase on body temperature above 38 °C. Negative feedback would be a response that opposed the temperature rise. Allowing perspiration to evaporate from the skin would cool the skin and lead to a decrease in body temperature. The effect of the other choices would be to increase body temperature.
    Author: rikazzz Comment