Question

can someone please explain this answer through punnett squares? Having troubles understanding the process.

141 In Drosophila, white eyes (w) and yellow body (y) are both recessive X-linked mutations. The wild type alleles, w+ and y+, control red eyes and dark body color, respectively. If a homozygous yellow body, red-eyed female is crossed with a dark body, white-eyed male, and F1 progeny are interbred, what will the phenotypes and ratios of the F1 and F2 be? osla 900 Answer: F1-females: all dark body, red eyes males: all yellow body, red eyes on the mou ntains og m is F2-females: yellow body, red eyes 1/2 on n g loob nitob dark body, red eyes—1/2 ingoto Solo qytonorig boo g ribavijo males: yellow body, red eyes-1/2 TO 2003 omolonidis nie netbold 2008 Somo dark body, white eyes-1/2 holosto ponto

Answer 1

both w and y genes are X linked.

genotype of the female who is homozygous for red eyes and yellow bodies is Xw+yXw+y and genotype of the male who has dark body and white eyes is Xwy+Y.

Xw+yXw+y * Xwy+Y.

	Xwy+	Y
Xw+y	Xw+yXwy+ (female with red eyes and dark body)	Xw+yY ( male with red eyes and yellow body)

so phenotype of the F1 progenies is

male: red eyes and yellow body

female: red eyes and dark body

F1 cross

Xw+yXwy+* Xw+yY

	Xw+y	Xwy+
w+y	Xw+yXw+y ( female with red eyes and yellow body)	Xwy+Xw+y ( female with red eyes and dark body)
Y	Xw+yY (male with red eyes and yellow body)	Xwy+Y ( male with white eyes and dark body)

females:

female with red eyes and dark body = number of female with red eyes and dark body/total number of females=1/2

female with red eyes and yellow body = number of females with red eyes and yellow body/total number of females=1/2

males:

male with red eyes and yellow body = number of male with red eyes and dark body/total number of males=1/2

males with white eyes and dark body= number of males with white eyes and dark body/total number of males=1/2