To study sex linkages in Drosophila, Morgan mated white eyed males with wild type red eyed females. What will be the phenotye of offspring?
Correct answer: A. All red eyed males and females
- A. All red eyed males and females
- B. Red eyed females and white eyed males
- C. White eyed females and red eyed males
- D. All white eyed females and males
Explanation
In Drosophila melanogaster, the gene for eye color is located on the X chromosome, and the white-eyed trait is a recessive mutation. The wild type, or normal, eye color in Drosophila is red, which is the dominant trait. When white-eyed males (homozygous for the recessive trait) are mated with wild type red-eyed females (homozygous for the dominant trait), the offspring will inherit one X chromosome from each parent. Since the white-eyed trait is recessive, the presence of a dominant red-eyed allele on the other chromosome will result in the offspring having red eyes. Therefore, all the offspring, both males and females, will have red eyes.
Last updated
About Inheritance
Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.
Practise Inheritance
1,238 free Inheritance MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
In birds the male is the homogametic sex. A male bird showing the recessive trait was mated with a female showing the dominant trait of a characteristic governed by a pair of alleles which are sex-linked. What is the probability that the male offspring will show the dominant trait?
"Law of independent assortment" states:
In 'Complete Dominance':
Which one is not a continuous trait?
Which trait is not sex-linked recessive?