In class Coat color in cats is a codominant trait and is als

In class: Coat color in cats is a codominant trait and is also located on the X chromosome. Cats can be black, yellow or calico. A calico cat has black and yellow splotches. In order to be calico. The cat must have an allele for the black color and an allele for the yellow color. Use a Punnett square to show why there are no male calico cats. A Labrador dog breeder has two black labs that he breeds every year. He takes careful records of the colors of offspring produced from the breeding. Over an eight year period, he has recorded 19 chocolate pups and 62 black pups. What are the probable genotypes of the two parents? Show the cross to prove it. The same Labrador dog breeder has two chocolate labs he mates yearly. Offspring produced from that mating are recorded: 34 are chocolate and 12 are yellow. What are the genotypes of the parents? Show the cross to prove it. In this same cactus as above, purple flowers are dominant to yellow flowers. A cactus that has both two-pronged and one-pronged spines has yellow flowers. It is crossed with a two-pronged cactus with purple flowers (heterozygous). What are the phenotypes of the offspring and in what proportion? A female calico cat is crossed with a male black cat. What are the phenotypes of the offspring and in what proportion.

Solution

THE SIMPLE LOGIC IS MALE HAVE ONLY ONE X CHROMOSOME WHERE AS FEMALE HAVE TWO X CHROMOSOMES. THE MALE EITHER HAVE THE X CHROMOSOME WITH BLACK OR YELLOW. AS THOSE ARE CO DOMINANT, CALICO IS NOT POSSIBLE IN THE MALES.

FOR EXPLNATION FIND THE BELOW PUNNET SQUARE

FEMALE X MALE

XbXy X Xb Y

GAMETES

MALE

FEMALE

Xb

Y

Xb

Xb Xb – female, black

Xb Y – male black

Xy

XY Xb – female, calico

Xy Y – male yellow

ACCORDING TO CHEGG GUIDE LINES WE HAVE TO ANSWER ONE QUESTION AT AT TIME, POST REST AS SEPERATE QUESTIONS. THEN I CAN HELP YOU. IF YOU NEED ANY FURTHER EXPLANATION COMMENT.

GAMETES	MALE
FEMALE	Xb	Y
Xb	Xb Xb – female, black	Xb Y – male black
Xy	XY Xb – female, calico	Xy Y – male yellow