Free Coordination and Control MCQs with Answers
1,687 Coordination and Control MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Coordination depends on receptors, neurons, synapses and nerve impulses, with reflex actions traced through the reflex arc and the roles of major brain regions. Chemical coordination covers endocrine glands and hormones, including how hormones regulate growth, metabolism, reproduction and internal balance, unlike rapid nervous control.
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- A. Photoperiodism
- B. Geotropism
- C. Thigmotropism
- D. Phototropism
Explanation: Thigmotropism is when a plant responds to a movement or touch from another stimulus.
Correct answer: Thigmotropism- A. Endogenous
- B. Exogenous
- C. Both (A) and (B)
- D. None of these
Explanation: Explanation for this question will be added soon!
Correct answer: Endogenous- A. Circadian rhythm
- B. Circannual rhythm
- C. Lunar rhythm
- D. All of the choices are correct
Explanation: Circadian (Latin circa =about, dies =day) means about one day.
Correct answer: Circadian rhythm- A. Dependent on light and temperature
- B. Exogenous in origin
- C. Independent of light and temperature
- D. All of the choices are correct
Explanation: Explanation for this question will be added soon!
Correct answer: Independent of light and temperature- A. Mechanical rhythm
- B. Chemotropism
- C. Photoperiodism
- D. Thigmotropism
Explanation: Photoperiodism is the response to changes in daylength that enables plants to adapt to seasonal changes in their environment.
Correct answer: Photoperiodism- A. Water deficit
- B. Oxygen deprivation
- C. Salt stress
- D. Herbivory
Explanation: It promotes closing of stomata under conditions of water stress (wilting).
Correct answer: Water deficit- A. 2-hour period
- B. 7-day period
- C. 24-hour period
- D. 365-day period
Explanation: Circadian rhythms are the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle.
Correct answer: 24-hour period- A. Water deficit
- B. Salt stress
- C. Cold stress
- D. Heat stress
Explanation: Among the accumulated metabolites as osmo-protectors, numerous carbohydrates, including fructose, sucrose, trehalose, raffinose, and…
Correct answer: Cold stress- A. Water stress
- B. Oxygen deprivation
- C. Salt stress
- D. Herbivory
Explanation: The formation of air tubes in submerged roots occur due to oxygen deprivation.
Correct answer: Oxygen deprivation- A. Gene for gene-recognition
- B. Production of oligosaccharides
- C. Production of phytoalexins
- D. Physical barrier of epidermis
Explanation: Cellulose cell walls form a physical barrier between the cells and pathogens, thus protect against infection.
Correct answer: Physical barrier of epidermis431. Auxin causes:
- A. Promotion of apical dominance
- B. Formation of adventitious roots
- C. Growth of fruit
- D. All of the choices are correct
Explanation: Auxin is a plant hormone responsible for growth nd development, helps in cell elongation of stems and roots, and promotes flowering.
Correct answer: All of the choices are correct- A. Ethylene
- B. Gibberellins
- C. Abscisic acid
- D. Cytokinin
Explanation: Cytokinins are a group of plant growth regulators which are primarily involved in performing cell division in plant roots, shoot system.
Correct answer: Cytokinin- A. Ethylene
- B. Gibberellins
- C. Abscisic acid
- D. Cytokinin
Explanation: Bakanae or "foolish seedling" is a common seedling disease in rice caused by the fungus Gibberellafujikuroi.
Correct answer: Gibberellins- A. Initiation of abscission
- B. Stimulation of abscission
- C. Prevention of abscission
- D. Acceleration of abscission
Explanation: Auxin delays abscission of young leaves and fruits. Its effect is through non-formation of abscission zone below a leaf or fruit.
Correct answer: Prevention of abscission435. Abscisic acid:
- A. Induces bud dormancy
- B. Causes the stomata to close
- C. Promotes senescence
- D. All of the choices are correct
Explanation: Abscisic acid (ABA) is a plant hormone that regulates numerous aspects of plant growth, development, and stress responses.
Correct answer: All of the choices are correct- A. Auxin
- B. Gibberellin
- C. Abscisic acid
- D. Ethylene
Explanation: Auxin herbicides stimulate a variety of growth and developmental processes when present at low concentrations at the cellular sites of…
Correct answer: Auxin- A. Hoshimata and Rappaport
- B. Donoho and Walker
- C. Yabuta and Hayashi
- D. Litrochet and Dolk
Explanation: Gibberellin was first discovered in 1935 by Teijiro Yabuta and Hayashi.
Correct answer: Yabuta and Hayashi- A. Dichlorophenoxy acetic acid
- B. Trichlorophenoxy acetic acid
- C. Gibbereellic acid
- D. Phosphon
Explanation: It stimulates cell division and expansion in response to light or dark.
Correct answer: Gibbereellic acid- A. International seed companies
- B. Plant pheromones
- C. Spray adjuvants
- D. Plant hormones
Explanation: Plant hormones (also known as phytohormones) are organic substances that regulate plant growth and development.
Correct answer: Plant hormones- A. Ethene
- B. Gibberellin
- C. Abscisic acid
- D. Cytokinin
Explanation: Cytokinin is a plant hormone. It plays major role in cell proliferation and cell division. During senescence, cytokinin levels are low.
Correct answer: Cytokinin