Question

A diploid plant has 14 chromosomes, but its egg cell has 6 chromosomes. Which one of the following is the most likely explanation of this?

• A. Non – disjunction in meiosis I & II
• B. Non – disjunction in meiosis-I
• C. Non– disjunction in mitosis
• D. Normal meiosis

Answer 1

The correct option is B Non – disjunction in meiosis-I

Failure of separation of homologous chromosomes in meiosis-I causes monosomy (one chromosome less) or trisomy (one chomosome extra) in the haploid set. This is a case of monosomy.