Question

An androgenic plant can be converted into homozygous diploid plant through the application of

• A. Nitrogen mustard
• B. Nitrous acid
• C. Colchicine
• D. Acridine orange

Answer 1

The correct option is C Colchicine

Nitrogen mustards (NMs) replace chloride by amine nitrogen and form aziridinium rings which in turn alkylate DNA. Nitrous acid converts cytosine to uracil, adenine to hypoxanthine by replacing their amino groups with keto groups. Uracil pairs with adenine, whereas its progenitor, cytosine, normally pairs with thymine; hypoxanthine pairs with cytosine, whereas its progenitor, adenine, normally pairs with thymine; thereby causing transition mutations. Acridine dye intercalates itself between base pairs of DNA chain thereby causing loss or gain of a single nucleotide. Colchicine disrupts the normal sequence of a nuclear division and induces somatic doubling by inhibiting microtubule formation which in turn prevents the spindle formation and thereby, prevents the chromosomes from moving apart during cell division (either mitosis or meiosis). This results in a cell with doubled chromosome number

So, the correct answer is 'Colchicine'