The male has two chromosomes X and Y, the female has only X chromosomes. During reproduction if X and X chromosome come together than the zygote shall develop into female if X and Y chromosome fuse, then zygote shall develop into male.
The sex of the offspring depends on whether he inherits X chromosome from father making it XX pair [female child] or Y chromosome from father making it XY pair [male child].
Also
if one parent has blood group A and second B, then
offspring may get AB.
If
one parent = A, second parent =O, then A;
If one parent = B, second parent =O, then offspring may get B;
If one parent = O, second parent =O, then offspring may
get O.
If one parent = AB, second parent =A/B/O, then offspring may get AB;
There
are 23 chromosomes, 22 autosomes and 1 pair of sex
chromosomes.
Genetic disorders are Hemophilia [sex chromosome linked passed from mother to son], Cystic fibrosis, Sickle-cell anemia [autosomal – can be passed from any parent to offspring], Color blindness [sex chromosome linked passed from mother to son, in rare cases to daughters if father is color blind and mother is a carrier], Phenylketonuria [autosomal], Thalassemia [ autosomal ] due to defective genes.
Allergic person release IgE antibody and the blood cells release histamines these cause allergic reactions.
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