Examples of dissimilar sex chromosomes are given below I. XX – XY  I II. XX – XO  II I and II in the above statement can be         I            II
a)	Man and most insect Cockroach and roundworms	b)	Cockroach and roundworms Man and most insect
c)	Butterfly Fishes	d)	Bird Reptiles

(a)

XY and XY type sex determination seen in many insect and mammals including humans. Males have X and Y chromosome along with autosome and females have pair of ‘X’ chromosome along with autosome

Parents    Phenotypes    Male                                      Female

                 Genotypes     44A + XY                                44A + XX

Gametes                      22A + X 22A+Y                      22A + A22A + X

                                         22A+ X               22A+X

Children   22A + X    44A + XX           44 A + XY    Female

                   22A + Y      44 A + XY          44 A + XY    Male

Sex ratio  Female : Male = 1 :  1

In plants The flowering plants are mostly bisexual and lack sex chromosomes. The unisexual flowering plants tent to have XX-XY type of sex chromosomal mechanism for sex determination. The female plants are XX and male plants are XY.

XX and XO Type of Sex Determination

Found in insect like grasshopper, cockroaches and bugs. Males have only X sex-chromosome and autosomes, female have pair of X-chromosome and autosome

Parents     Phenotypes      Male            Female

                    Genotypes           

Gametes                       

-generation

XX-XO type of sex determination