Answer:
II and III
Explanation:
I. All sons of these parents will be a hemophiliac.
II. A son who suffers from hemophilia received the hemophilia allele from his mother.
III. Half of the daughters of this cross are predicted to be hemophiliacs.
Assuming the haemophilia allele is represented by h, the alternate form being H.
A woman that is a carrier will have the genotype [tex]X^H X^h[/tex].
A man who suffers from haemophilia will have the genotype [tex]X^h Y[/tex]
Crossing both of them:
[tex]X^H X^h[/tex] x [tex]X^h Y[/tex] = [tex]X^H X^h, X^H Y, X^hX^h and X^hY[/tex]
From the result of the cross, the following can be deduced:
Hence, statements II and III are true.
I. All sons of these parents will be a hemophiliac.
II. A son who suffers from hemophilia received the hemophilia allele from his mother.
III. Half of the daughters of this cross are predicted to be hemophiliacs
Answer:
II and III are correct
Explanation:
II. A son who suffers from hemophilia received the hemophilia allele from his mother.
The male sex chromosomes is XY. Since the Y -chromosome of the father does not bear the haemophilia allele,its inheritance to determine the sex of the child is not associated with the haemophilia. Y-chromosomes does not bear any allele.Only one of the X-chromosomes of the carrier mother should possess the haemophiliac gene. Therefore a son who is haemophiliac definitely inherited heamophilic - X-chromosomes from the mother(r(,assuming he picked the defective X-allele of the carrier mother ) and heamophilic Y-chromosomes fro.m the father. XcY.
III. Half of the daughters of this cross are predicted to be hemophiliacs.
No doubt the daughter chromosomes are XX. The father is haemophiliac, thus his X-Chromosomes carries the allele for heamophlia The mother carrier XX chromosomes shows that at least one of the X-chromosomes has haemophiliac gene. Therefore the probability is that half of the daughters will be haemophiliac assuming one of this daughters inherited the defective allele on one of the X-chromosomes of the carrier mother, the haemophiliac X-chromosomes from the father.
The other daughter may be a carrier assuming, she inherited haemophiliac X- gene from the father, and the heamophilia free X-chromosomes from the carrier mother. XcX
let C- rep. heamophila.
let the haemophiliac father be-XcY
let the haemophiliac mother be XcX
based on mono-hybrid cross.
XcY x XcX
XcXc XcY XXc XY
→haemophiliac girl XcXc
→ haemophiliac boy XcY
→carrier girl XXc
→Normal boy -XY.
Evidently from the cross I is WRONG
