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Body Fluids And Circulations

Question
CBSEENBI11003243

Haemophilia is more commonly seen in human males than in human females because

  • this disease is due to an X- linked dominant mutation

  • a greater proportion of girls die in infancy

  • this disease is due to an X- linked recessive mutation

  • this disease is due to a Y- linked recessive mutation

Solution

C.

this disease is due to an X- linked recessive mutation

Haemophilia is a hereditary (recessive X- linked) disease caused due to fault in genes, controlling the factors VIII and IX, on X chromosome. 

Males have one X and Y chromosome each. Y chromosome does not carry any gene for blood clotting. Therefore, this condition is usually seen in males as they carry only one faulty X chromosome.

Females are generally the carrier of the disease as in females, two faulty X- chroromsomes are needed to cause the disease.