This document discusses sex determination in honey bees. It notes that honey bees have three castes - queens, workers, and drones. Queens are the largest females and are fertilized, workers are smaller females that are also fertilized, and drones are parthenogenetic males. The sex of honey bees is determined by their number of chromosome sets (haploid or diploid) rather than sex chromosomes. Females are diploid and develop from fertilized eggs, while males are haploid and develop from unfertilized eggs through parthenogenesis. Therefore, the sex determination system in honey bees is called haplodiploid, where sex is determined by ploidy level rather than specific sex chromosomes.

1. SEX
DETERMINATIION
IN
HONEY BEE

2. INTRODUCTION
Birds show well marked
sexual dimorphism. They have
three castes in their hive as :-
Queen – fertilized largest female.
Worker – fertilized smaller
females.
Drone – parthenogenetic males.

3. CHROMOSOMES IN HONEY BEES
 They have 16 pairs of homologous
chromosomes.
 Females are diploid with 36 or 16
pairs of chromosomes and males are
haploid with only 16 or one set of
chromosomes. So sex determination
in honey bee is called as
HAPLODIPLOID SYSTEM OF SEX
DETERMINATION.

4. THEORIES OF SEX
DETERMINATIION IN HONEY BEE
Chromosomal Theory

5. CHROMOSOMALTHEORY
Here sex of an individual is determined by
number of sets of chromosomes in it or
occurrence or absence of fertilisation of
gametes.
Here females developed from fertilisation
of sperm and ovum and males develops by
parthenogenesis.
Parthenogenesis is a phenomenon in
which unfertilised ovum develops into
offspring without fertilisation.
So males are haploid and females diploid.

6. GENERATIONS CROSS
QUEEN DRONE
PARENTS
GAMETES
F 1
nnn
FertilisationParthenogenesis
DRONE QUEEN,
WORKER

7. CONCLUSION
From above descriptions, we conclude
that, the it is not sex chromosomes but
number of sets of chromosomes and
occurrence or absence of fertilisation,
determine the sex of honey bees.
This system is also seen among ants,
wasps, spiders, mites etc..

8. EXTRAAND INTERESTING
ARRHENOTOKY – It is the development
of unfertilised egg into male by
parthenogenesis.
THELYTOKY - It is the development of
unfertilised eggs into female by
parthenogenesis. It is seen among
Hymenopteran insects such as ants, wasps,
bees, sawflies etc..
Honey bees drones do not have father but
have inheritance from the grandfather.