Asked by Amber Kinsey on May 07, 2024
Verified
In fruit flies, bar eye is inherited by a dominant X-linked allele (B for bar) . If a heterozygous bar-eyed female is mated to a non-bar-eyed male, what will be the expected ratio of phenotype given four offspring?
A) two bar-eyed females, two bar-eyed males
B) one bar-eyed and one non-bar-eyed female, one bar-eyed and one non-bar-eyed male
C) three bar-eyed females and one non-bar-eyed male
D) bar-eyed females only
E) non-bar-eyed males only
X-linked Allele
A gene located on the X chromosome that can lead to specific traits or diseases depending on its inheritance pattern.
Bar Eye
A genetic mutation in fruit flies that leads to an elongated eye shape, often used in genetics studies.
Heterozygous
Referring to an individual having two different alleles for a particular gene, one inherited from each parent.
- Comprehend the fundamental concepts of genetic inheritance, such as dominant, recessive, and X-linked characteristics.
- Understand the influence of genetic linkage and crossing over on the inheritance of genes.
Verified Answer
MA
Mohammed Al BaderMay 11, 2024
Final Answer :
B
Explanation :
The heterozygous bar-eyed female would have one X chromosome with the dominant B allele and one X chromosome with the non-bar-eyed allele. The non-bar-eyed male would only have non-bar-eyed alleles. The expected ratio of phenotypes would be one bar-eyed female (with the dominant B allele on her X chromosome), one non-bar-eyed female (with the non-bar-eyed allele on her X chromosome), one bar-eyed male (with the dominant B allele on his X chromosome), and one non-bar-eyed male (with the non-bar-eyed allele on his X chromosome). Therefore, choice B matches this expected ratio.
Learning Objectives
- Comprehend the fundamental concepts of genetic inheritance, such as dominant, recessive, and X-linked characteristics.
- Understand the influence of genetic linkage and crossing over on the inheritance of genes.