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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121. Which of the following is antagonist to Auxin in terms of promotion of stem growth______________?
- A. Gibberellins
- B. Cytokinins
- C. Abscisic Acid
- D. none of these.
Explanation: Abscisic acid inhibits cell growth and promotes dormancy, whereas auxin promotes cell elongation and stem growth, so they act…
Correct answer: Abscisic Acid- A. White
- B. Red
- C. Blue
- D. Green
Explanation: In some long-day plants, gibberellin treatment can replace the flowering effect normally produced by a red-light-dependent long-day…
Correct answer: Red- A. Indole propionic acid.
- B. Indole carboxylic acid.
- C. Indole acetaldehyde
- D. Indole acetic acid.Scheduling Virtual Doctor Consultations
Explanation: The principal natural auxin is indole-3-acetic acid, commonly written as indole acetic acid or IAA.
Correct answer: Indole acetic acid.Scheduling Virtual Doctor Consultations- A. Accumulation of toxic waste products in leaves.
- B. Deficiency of chlorophyll.
- C. Short supplies of mineral nutrients in the soil.
- D. All of these
Explanation: Chlorosis is the yellowing of leaves caused by reduced chlorophyll, and it can result from mineral deficiency or injury caused by…
Correct answer: All of these- A. IAA
- B. NAA
- C. 2 4-D
- D. GA
Explanation: 2,4-D is a synthetic auxin that acts as a selective herbicide, especially against many broad-leaved weeds.
Correct answer: 2 4-D- A. ADH
- B. MSH
- C. Oxytocin
- D. Progesterone
Explanation: Oxytocin stimulates contraction of the uterine smooth muscle during labour and also helps the uterus contract after birth, reducing…
Correct answer: Oxytocin- A. Photoperiodism
- B. Thermotropism
- C. Vernalisation
- D. Thermoregulation
Explanation: Vernalisation is the induction or acceleration of flowering after exposure to a prolonged period of low temperature.
Correct answer: Vernalisation- A. Turgor movements
- B. Growth movements
- C. Tactic movements
- D. Paratonic movments
Explanation: Sleep movements in plants are usually turgor movements, produced by reversible changes in water content and pressure in specialised motor…
Correct answer: Turgor movements- A. Diffusion
- B. Passive transport
- C. Osmosis
- D. Active transport
Explanation: Moving sodium ions from lower to higher concentration requires energy from ATP and is therefore active transport, carried out by membrane…
Correct answer: Active transport- A. Nervous system
- B. Brain
- C. Spinal cord
- D. All of above
Explanation: The nervous system connects the brain with the rest of the body through sensory and motor neurons, allowing information to travel in both…
Correct answer: Nervous system- A. Effectors neurons
- B. Receptor neurons
- C. Stimulators
- D. Detector neurons
Explanation: The dorsal root of a spinal nerve carries sensory, or afferent, fibres entering the spinal cord from receptors.
Correct answer: Receptor neurons- A. 10,000,00
- B. 100,000,000
- C. 100,000,000,000
- D. 1000
Explanation: The human brain contains approximately 86 billion neurons, which is commonly rounded in older exam material to about 100,000,000,000…
Correct answer: 100,000,000,000- A. Conduction
- B. Regeneration
- C. Reflex
- D. Movement
Explanation: Regeneration is not a normal defining function of neurons, which are specialized mainly for receiving, conducting and transmitting…
Correct answer: Regeneration- A. 0.03 V
- B. 0.05 V
- C. 0.07 V
- D. 0.09V
Explanation: The resting membrane potential of a typical neuron is about -0.07 V, meaning the inside is approximately 0.07 V more negative than the…
Correct answer: 0.07 V- A. Parkinson's disease
- B. Epilepsy
- C. Alzheimer's discease
- D. Dementia
Explanation: Epilepsy is a convulsive neurological disorder caused by abnormal, excessive electrical activity in the brain, producing temporary motor…
Correct answer: Epilepsy- A. Brain
- B. Spinal cord
- C. Both of these
- D. none of these.
Explanation: The vertebral column encloses and protects the spinal cord, which is part of the central nervous system and carries impulses between the…
Correct answer: Spinal cord- A. Brain
- B. Spinal cord
- C. Both of these
- D. none of these
Explanation: The central nervous system consists of the brain and spinal cord, which together receive, process and coordinate nervous information.
Correct answer: Both of these- A. Na+
- B. K+
- C. Fe
- D. none of these
Explanation: Sodium ions initiate a nerve impulse when voltage-gated sodium channels open and Na+ enters the neuron, causing rapid depolarization of…
Correct answer: Na+- A. Outer surface of neuron is more positive
- B. Inner surface of neuron is more positive
- C. Both of these surfaces are equally positive
- D. none of these.
Explanation: During the resting state, the outside surface of the neuron is relatively positive and the inside is relatively negative because of ion…
Correct answer: Outer surface of neuron is more positive- A. To allow nerve impulse to move in backward direction
- B. To decrease the speed of nerve impulse
- C. To stop the nerve impulse
- D. To provide cytoplasmic connection between neurons.
Explanation: A synapse produces a small synaptic delay because neurotransmitter release and reception take time, so transmission across a synaptic…
Correct answer: To decrease the speed of nerve impulse