Multiple Choice
Tortoise shell cats have variegated coat colors caused by X-inactivation and are always what?
183
views
13. Mendelian Genetics
X-Inactivation
Struggling with General Biology?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
In cats, fur color is determined by an X-linked gene; There are two alleles for this gene, one allele is for black fur and the other is for orange fur. In cats, a heterozygote female has calico (black and orange patches) colored fur. What kinds of offspring would you expect from the mating of a black female and an orange male?
A
Calico females & calico males.
B
Black females & orange males.
C
Calico females & black males.
D
Orange females & black males.
Verified step by step guidance1
Understand that fur color in cats is determined by an X-linked gene, meaning the gene is located on the X chromosome. This is important because males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).
Identify the alleles involved: the allele for black fur (B) and the allele for orange fur (O). A female cat with one black allele and one orange allele (BO) will have calico fur due to the presence of both alleles.
Determine the genotype of the parents: The black female will have the genotype BB (since she has two X chromosomes, both carrying the black allele), and the orange male will have the genotype OY (since he has one X chromosome carrying the orange allele and one Y chromosome).
Predict the possible combinations of alleles in the offspring: The female offspring will inherit one X chromosome from each parent, resulting in BO (calico) or BB (black). The male offspring will inherit the X chromosome from the mother and the Y chromosome from the father, resulting in BY (black).
Conclude the expected phenotypes of the offspring: The female offspring will be calico, and the male offspring will be black.
Related Videos
Related Practice
