Question

Given below are two statements: Assertion (A): Tetrazolium test is conducted to determine the viability of seeds of certain species which germinate slowly or show a high degree of dormancy. Reason (R): In this test, living cells are made visible by reduction of an indicator dye, 2,3,5-triphenyl tetrazolium chloride.

• A. Both A and R are correct and R is the correct explanation of A
• B. Both A and R are correct but R is not the correct explanation of A
• C. A is correct but R is not correct
• D. A is not correct but R is correct

Hint:

Tetrazolium test is a quick seed viability test. Living seed tissues stain red due to reduction of tetrazolium chloride.

Answer 1

The Correct Option is A

Concept:
Tetrazolium test is a biochemical test used to determine seed viability quickly. It is especially useful when seeds germinate slowly or show dormancy.

Step 1: Check Assertion (A).
The assertion states that tetrazolium test is used to determine seed viability in species that germinate slowly or show dormancy. This is correct because normal germination tests may take a long time in such seeds. \[ A \text{ is correct} \]

Step 2: Check Reason (R).
In tetrazolium test, living seed tissues reduce 2,3,5-triphenyl tetrazolium chloride into a red coloured compound. \[ \text{Living tissue} \rightarrow \text{Red staining} \] Dead tissues do not stain properly. \[ R \text{ is correct} \]

Step 3: Check whether R explains A.
The reason explains how the tetrazolium test determines viability. Since living cells reduce the dye and become visible, the test can identify viable seeds quickly. \[ R \text{ correctly explains } A \] \[ \therefore \text{Correct Answer is (A)} \]