Download App

Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYMicrobes in Human Welfare1 Mark
MCQ
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: Azotobacter fixes nitrogen in symbiotic form.
Reason: Azotobacter form root nodules in the roots of leguminous plants.
  • A
    Both assertion and reason are true and reason is the correct explanation of assertion.
  • B
    Both assertion and reason are true but reason is not the correct explanation of assertion.
  • C
    Assertion is true but reason is false.
  • ✓
    Both assertion and reason are false.
✓

Answer

Correct option: D.
Both assertion and reason are false.

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 Microbes in Human Welfare→Microbes in Human Welfare — all question types→BIOLOGY STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Assertion (A): Determining the sex of an unborn child followed by MTP is an illegal practice.
Reason (R): Amniocentesis is a practice to test the presence of genetic disorders also.
→
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: At the time of implantation, which takes place in $14$ days, the human embryo is called blastocyst.
Reason: Implantation occurs in the gastrula stage.
→
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: The subunits of ribosomes come together only at the time of protein formation.
Reason: $Mg^{2+}$ causes their association or dissociation.
→
Assertion (A): Generally, a woman does not conceive during the lactation period.
Reason (R): The hormone 'prolactin initiates and maintains lactation in a postpartum woman.
→
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: Ubisch bodies are produced by glandular tape tum.
Reason: Ubisch bodies participated in the thickening of exine.
→
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: Species diversity decreases as we ascend towards high mountains.
Reason: Due to drop in temperature, no seasonal variability occurs in high mountains.
→
Assertion (A): In India, there is rapid decline in infant mortality rate and MMR.
Reason (R): In India, more and more attention is being given to RCH programmes.
→
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: Ribosomes attached to endoplasmic reticulum release proteins into lumen of $ER.$
Reason: Such proteins are used for formation of hydrolytic enzymes or are modified.
→
$Bt$ toxin is harmful to insects like:
→
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: $\text{Z-DNA}$ follows a zig$-$zag course.
Reason: $\text{Z-DNA}$ is left handed.
→