5. Yes.. In turner syndrome every cell of body contains only 45 chromosomes
(44 + X0)..it is monosomy.
It happened when abnormal 22 +0 male sperm fuses with normal 22 +X female.
Or when abnormal female ovum fuses with normal sperm.
The Zygote if formed has 1 copy missing of X chromosomes.. When this zygote undergoes goes mitosis every cell will only 1 coly of X chromosomes.
6. No.. Bcoz in down syndrome.. There is extra copy of chromosome no. 21..
(45 +XX) or (45+XY). No.. They can't give rise to normal child.
Also
Males having down syndrome have very rare chances of being fertile.
7.yes..in case of XXYY syndrome.
In this abnormal male gametes (22+YY) fuses with abnormal female gametes
22+XX.
8. Color blindness is reccessive sex linked disease..
In females there are two copies of X.. Nit present in males and girls having Turner's syndrome.
Hope this helps you