Download App

Human Health and Disease — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease1 Mark
MCQ
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Immunoglobutin functions as antibody.
Reason: Different inununoglobulins molecules have different antigen binding properties.
  • A
    Both assertion and reason are true and reason is the correct explanation of assertion.
  • ✓
    Both assertion and reason are true but reason is not the correct explanation of assertion.
  • C
    Assertion is true but reason is false.
  • D
    Both assertion and reason are false.
✓

Answer

Correct option: B.
Both assertion and reason are true but reason is not the correct explanation of assertion.
Immunoglobulins are a complex hetero $-$ geneous mixture of proteins that are produced by plasma cells in response to an immunogen. It generally assume one of two roles$- (i)$ plasma membrane bound antigen receptors on the surface of $B$ cell, or $(ii)$ as antibodies free in cellular fluids functioning to intercept and eliminate antigenic determinants. It exhibit two fundamental types of structural variation. Subtle structural differences in their antigen combining sites, or variable regions, account for their unique antigen binding specificities. Structural differences outside their antigen combining sites, in the so$-$called constant regions, correlate with the different effector functions mediated by antibodies, such as complement activation or binding to one or more of the antibody $Fe$ receptors expressed on monocytes and granulocytes. The variable and constant regions of antibodies arise from distinct structural domains. Each antibody class is distinguished by certain effector functions and structural features including a unique heavy $(H)$ chain isotype, designated $\alpha (\text{IgA)},\delta (\text{IgD}),\in(\text{IgE}),\gamma(\text{IgG}),\mu(\text{IgM}).$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Human Health and Disease→Human Health and Disease — all question types→BIOLOGY STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Initiation step of protein synthesis in prokaryotes and eukaryotes has several differences.
Reason: They both form $\text{mRNA - tRNA}$ complex with smaller subunit of ribosome.
→
Two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Type  restriction endonucleases are not used in recombinant $\text{DNA}$ technology.
Reason: Type  restriction endonucleases recognise specific sites within the $\text{DNA}$ but do not cut these sites.
→
For question two statements are given $-$ one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Many mangrove plants possess high levels of organic solutes.
Reason : This is an adaptation to cope with the conditions of high salt concentration and osmotic potential.
→
For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $\text{(a), (b), (c)}$ and $(d)$ as given below.
Assertion : The principle of segregation given by Mendel is the principle of purity of gametes.
Reason : Gametes are pure for a character.
→
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Buffer zone surrounds the core area and limited human activities like resource use strategies, research and education are allowed here.
Reason: There is no biotic interference except in buffer zone.
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Psychotropic drugs affect behaviour and mental activities
Reason: Tranquillizer, a psychotropic drug, decrease tension and anxiety.
→
Silencing of a gene could be achieved through the use of :
→
For question two statements are given $-$ one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Kangaroo rat can live without drinking water.
Reason : This is an adaptation to water scarcity in arid conditions.
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Synthesis of tryptophan is self regulatory.
Reason: Tryptophan works both as co$-$repressor and through feedback inhibition.
→
For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $\text{(a), (b), (c)}$ and $(d)$ as given below.
Assertion: In a monohybrid cross, $F_1$ generations indicate dominant characters.
Reason: Dominance occurs only in heterozygous state.
→