Subject

Biology

Class

NEET Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

21.

Assertion: Translocation of sugar from source (leaf) to sink is defined as pressure flow hypothesis.

Reason: Translocation of the solute is facilitated through living phloem sieve tube cells.

  • 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.


22.

Assertion: Black rust of wheat is a hazardous disease which is caused by Puccinia fungus.

Reason: Aflatoxin is produced in the groundnut by the infection of a bacterium.

  • 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.


23.

Assertion: Cephalisation is advantageous to an animal.

Reason: Cephalisation improves the appearance of an animal.

  • 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.


24.

Assertion: Secondary metabolites are produced in small quantities and their extraction from the plant is difficult and expensive.

Reason: Secondary metabolites can be commercially produced by using tissue culture technique.

  • 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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25.

Assertion: Yeasts are unicellular fungi that are used in bakery and brewery industries.

Reason: Potato spindle tuber disease is caused by viroids

  • 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.


26.

Assertion: Pulmonary circulation consists of flow of deoxygenated blood from right ventricle to the lungs and flow of oxygenated blood from lungs to the left atrium.

Reason: Systemic circulation consists of flow of oxygenated blood from the left ventricle to all parts of the body and deoxygenated blood from different parts to right atrium

  • 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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27.

Assertion: ADH and RAAS work in response to low blood volume and blood pressure.

Reason: ANF works in response to high blood volume and blood pressure.

  • 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.


B.

If both assertion and reason are true but reason is not the correct explanation of assertion.

ADH (Antidiuretic hormone) and RAAS (Renin Angiotensin Aldosterone System) work in response to low blood volume and low blood pressure. ADH increases the reabsorption of water in the distal convoluted tubule and collecting duct and thus results in an increase in blood volume and blood pressure.

RAAS is operated by JGA (Juxtaglomerular apparatus). It increases blood volume and blood pressure by two ways:
Firstly, it induces the proximal convoluted tubules to reabsorb more NaCl and water and,
Secondly, it stimulates the adrenal glands to release a hormone, called aldosterone that induces the distal convoluted tubule to absorb more Na" and water.

ANF (Atrial Natriuretic Factor) works in response to high blood volume and high blood pressure. It opposes the regulation by RAAS. The walls of the atria of the heart release ANF in response to an increase in blood volume and blood pressure. ANF inhibits release of renin from the JGA and thereby inhibits NaCl reabsorption by the collecting duct and reduces aldosterone release from the adrenal gland.

Thus ADH, RAAS and ANF regulate the functions of kidneys and control body fluid osmolarity, salt concentration, blood pressure 1 and blood volume.


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28.

Assertion: Endomycorrhiza of forest trees contribute to the efficient nutrient cycling in tropical forest ecosystems.

Reason: The fungi that formendo-mycorrhizal associations with plants make nutrient ions available to them.

  • 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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29.

Assertion: Conversion of 1,3 biphosphoglycerate (BPGA) to 3-phospho-glyceric acid (PGA) is an energy yielding step.

Reason: This energy is trapped in the form of ATP

  • 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.


30.

Assertion: On stimulation, a muscle cell releases calcium ions (Ca2+) from sarcoplasmic
reticulum.

Reason: By reacting with a protein complex, Ca uncover active sites on the actin filaments

  • 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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