Concept explainers
Why is the white-eye
a. Because the trait is dominant
b. Because the trait is recessive
c. Because the allele is located on the X chromosome and males only have one X
d. Because the allele is located on the Y chromosome and only males have Y chromosomes
Introduction:
The sex chromosomes are those chromosomes that determine the sex of the organism. The females have a pair of X chromosomes, whereas, the males have a pair of dissimilar chromosomes (one X chromosome and one Y chromosome).
Answer to Problem 1U
Correct answer:
The white-eye phenotype is always observed in males carrying the white-eye allele because the allele is located on the X chromosome and males only have one X chromosome. Therefore, option c. is correct.
Explanation of Solution
Reason for the correct statement:
The gene responsible for the appearance of the white eye phenotype is present only on the X chromosome and it is not present on the Y chromosome.
Option c. is given as “because the allele is located on the X chromosome and males only have one X”.
As, “the Y chromosome lacks the gene responsible for the expression of the white eye phenotype and X chromosome has it. It is observed only in the males”, it is the right answer.
Hence, option c. is correct.
Reasons for the incorrect statements:
Option a. is given as “Because the trait is dominant”.
The trait will be dominant if it is expressing in the heterozygous or homozygous dominant conditions. Here, it cannot be determined that whether the condition is dominant or not. So, it is a wrong answer.
Option b. is given as “Because the trait is recessive”.
The trait will be recessive if it is expressing in the homozygous recessive conditions. Here, it cannot be determined that whether the condition is homozygous or not. So, it is a wrong answer.
Option d. is given as “Because the allele is located on the Y chromosome and only males have Y chromosomes”.
The allele for the gene responsible is not present on the Y chromosome. So, it is a wrong answer.
Hence, options a., b., and d. are incorrect.
The gene responsible for the white eye phenotype is present on the X chromosome only and males only have X chromosome and the Y chromosome does not have that gene.
Want to see more full solutions like this?
Chapter 13 Solutions
BIOLOGY CONNECT ACCESS CARD
- Which event leads to a diploid cell in a life cycle? a. meiosis b. fertilization c. alternation of generations d. mutationarrow_forwardBiology When both parents are heterozygous carriers of the recessive allele that causes albinism, what percentage of their offspring will be heterozygous carriers of the albinism allele? Answer Choices: A: 25% B: 50% C: 75% D: 100%arrow_forwardA trait such as having a crooked thumb is produced by a ?arrow_forward
- Evaluate the effect of crossing over on the genetic composition of an organism AND explain the effect crossing over on genetic diversity in a population.arrow_forwarduse the pedigree and answer : What is the genotype of the son with no white lock of hair? what is the genotype of the son with the white lock of hair? What is the genotype of the daughter with the white lock of hair ?arrow_forward(short answer) Imagine you’ve been offered a deal from a genomics company. You can get a free genome sequence – an analysis of all of your DNA that includes a report of your ancestry, traits and a medical profile. The medical profile tells you about diseases for which you have a low risk of getting, and also those you have a high risk of getting. Are you interested? Why or why not?arrow_forward
- Give written answer with explanation and conclusion A cross was made between a white male dog and two different black females. The first female gave birth to eight black pups, and the second female gave birth to four white and three black pups. What are the likely genotypes of the male parent and the two female parents? Use Punnett’s squares to support your answer. Explain whether you are uncertain about any of the genotypes.arrow_forwardInterpret phenotypic ratios of progeny to infer howparticular traits are inherited.arrow_forwardShort Answer: What are environmental effects in genes?arrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College