A male honeybee has 16 chromosomes whereas its female has 32 chromosomes. Give one reason.

Matre Holey bee develops from unfertilized female  gamete / unfertilised egg / Parthenogenesis of female gamete (16 chromosomes), female develops  by fertilization / fertilised egg (32 chromosomes)

Detailed Answer : 

Male honeybees airborne, from the unfertilised eggs by the process known as parthenogenesis whereas female honeybees are borne, from fertilised egg. Since unfertilised egg carries only half the number of chromosomes as compared to fertilised egg, male honeybees have half the number of chromosomes (n) as compiled to female honey bee (2n)

Male honeybee develops from unfertilised female gamete (Parthenogenesis) and thus has 16 chromosomes whereas female develops by fertilisation and thus has 32 chromosomes.