Question

Regarding assertion and reason, choose the correct option
Assertion [A]: Meristem culture is the best method to get virus free plants.
Reason [R]: Meristems divide rapidly and do not allow virus multiplication.

• A. Both A and R are true and R explains A
• B. Both A and R are true but R does not explain A
• C. A is true and R is false
• D. Both A and R are false

Answer 1

The correct option is A Both A and R are true and R explains A

Most crops are infected by systemic diseases caused by viruses. It is possible to produce virus free plants through tissue culture. Apical meristems in the infected plants are generally either free or carry a very low concentration of the virus. This is because of three main reasons :
a) Viruses move readily in a plant body through the vascular system in which primary meristem is absent.
b) A high metabolic activity in the actively dividing meristematic cells does not allow virus replication and
c) A high endogenous auxin level in shoot apices may inhibit virus multiplication.
So, meristem culture is one of the best methods exploited for producing virus free plants.