Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

Klinefelter's syndrome is represented by 44 autosomes + XXY. When an abnormal egg with $\mathrm{XX}$ chromosome is fertilized by a sperm carrying Y-chromosome a zygote having $\mathrm{XXY}$ sex chromosomes is formed. The resulting young one is an abnormal sterile male. The 44 autosome + XO condition is due to Turner's syndrome. Such females are sterile and have short stature, webbed neck, broad shield-shaped chest etc. Down's syndrome is due to trisomy of $21^{\text{st }}$ pair of chromosome. It is characterised by moderate mental retardation, large tongue, short stature, stubby fingers, an enlarged liver and spleen. Colourblindness is an X-linked disease. The person suffering from this disease cannot differentiate between red and green colours. Erythrobalstosis-foetalis is caused due to $\mathrm{Rh}$ factor in child of ${\mathrm{Rh}}^{+}$man and ${\mathrm{Rh}}^{-}$woman.