Multiple Choice QuestionsAssertion: Mylein sheath insulates the nerve fibre and prevents its depolarisation.
Reason: Nerve impulses are conducted more rapidly in non - myelinated nerve fibres than in myelinated ones.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
C.
If assertion is true but reason is false.
In non-myelinated nerve fibres, the ionic changes are repeated over the membrane all along the length of the fibre. So, the action potential flows all along the membrane over the entire length of the fibre. But in myelinated fibres, the ionic changes and the consequent depolarisation can take place only at the nodes of Ranvier free from myelin sheath, because the myelin sheath between the nodes insulates the fibre and prevents its depolarisation. So, the action potential in effect jumps from one node to the next.This is called saltatory conduction of nerve impulses. Because of this, nerve impulses do not have to run all along the myelinated nerve fibre. This is why nerve impulses are conducted far more rapidly in myelinated fibres than in the non - myelinated ones.
Assertion: Frog can change its colour, according to its surroundings.
Reason: It is a way of mimicry to capture preys
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
Assertion: Less iodine intake causes goitre.
Reason: Less iodine in body decreases thyroxine secretion
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Excess Mn in soil, can adversely decrease Mg, Fe and Cu concentrations in the soil.
Reason: Mn increases rate of photosynthesis, thereby increasing absorption of Mg, Fe and Ca from soil.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
Assertion: In proximal convoluted tubule glomerular filtrate becomes hypertonic to blood plasma.
Reason: HCO3- is absorbed only in the proximal convoluted tubule.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
Assertion: Complexity of classification increases from kingdom to species.
Reason: Common characters increase from kingdom to species.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
Assertion: Emulsification is necessary for the digestion of fats.
Reason: After fats are emulsified, the action of enzyme amylase gets significantly increased.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: In jaundice, the skin and mucous membranes assume a yellowish hue
Reason: Yellow pigment bilirubin imparts pale yellow colour to blood plasma
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: No taste sensation is evoked when drop of distilled water is put on human tongue.
Reason: Man does not possess taste buds for tasting water.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Oxytocin is also known as Antidiuretic hormone (ADH).
Reason: Oxytocin can cause an increase in the renal reabsorption of water.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
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