Meiosis occursin organisms during

1.  sexual reproduction

2.  vegetative reproduction

3.  Both (a) and (b)

4.  None of these

Class 11 pg 167
(a) Meiosis occurs in Sexually reproducing organisms to reduce the chromosome number to half before their gametes unit, so, as to maintain the constant chromosome number (2n) in the progeny.
Vegetative reproduction is a kind of asexual reproduction occurring in plants and does not involve the formation and fusion of gametes.