Download App

Human Health and Disease — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease1 Mark
MCQ
For 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 : Allergy is an immunity disorder.
Reason: Allergy is confined to a person only.
  • 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.
Allergy is non$-$infectious unusual reaction or hypersensitivity of an individual to a foreign substance or agent that may be harmless to other individuals $($thus it is considered as immunity disorder$).$ It is non$-$communicable as it is confined to a person only and does not spread from one person to another. The foreign substance or allergen on first contact functions as mild antigen. It produces antibodies which remain attached with the mast cell. Lysis of mast$-$cells occur, which releases histamine as allergy mediator.

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→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

For 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: In morula stage, the cells divide without any increase in size.
Reason: Zona pellucida remains undivided till cleavage is complete.
→
For 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.
→
Assertion: Gene flow increases genetic variations.
Reason : The random introduction of new alleles into the recipient population and their removal from the donor population affects allele frequency.
→
For 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: $\text{PCR, ELISA, DNA}$ hybridisation are confirmatory tests for sexually transmitted diseases.
Reason: Incidence of $\text{STDs}$ are very high in persons above the age of $30.$
→
For 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: In human male, testis are extra abdominal and lie in scrotal sacs.
Reason: Scrotum acts as thermoregulator and keeps testicular temperature lower by $2^\circ C$ for normal spermatogenesis.
→
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: Bacteriophage vectors are more advantageous than plasmid vectors.
Reason: Bacteriophage vectors can be easily detected at the time of cloning experiments.
→
Directions: In the following questions, the Assertions $(A)$ and Reason$(s) (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Restriction endonucleases recognize short palindromic sequence and cut at specific sites.
Reason: When a restriction endonuclease acts on a palindrome, it cleaves both the strands of $\text{DNA}$ molecule.
→
For 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: Azolla is used as a biofertiliser in rice fields.
Reason: Azolla shows the presence of $N_2-$ fixing bacteria in its leaf cavities.
→
Name any genetically modified crop.
→
For 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: Hybrids are generally superior than their parents.
Reason: All the dominant traits are present in the hybrid.
→