Sex-linked traits are characteristics that are determined by genes located on the sex chromosomes (X or Y). Because females have two X chromosomes (XX) and males have one X and one Y chromosome (XY), the inheritance patterns of these traits differ between the sexes. Most sex-linked traits are found on the X chromosome. Conditions like hemophilia and color blindness are classic examples of X-linked recessive disorders.
Understanding how these traits are passed down requires careful consideration of the genotypes of both parents and the probabilities of different allele combinations in their offspring. Punnett squares are invaluable tools for visualizing and predicting these inheritance patterns.
Match each term with its correct definition:
| Term | Definition |
|---|---|
| 1. Hemizygous | A. A person who has one recessive allele for a recessive trait but does not display the trait. |
| 2. Carrier | B. Genes located on the X or Y chromosome. |
| 3. Sex-linked gene | C. Having only one copy of a gene (e.g., males for X-linked genes). |
| 4. X-linked recessive | D. More males than females are affected. |
| 5. X-linked dominant | E. Trait that requires only one copy of the affected allele to present the phenotype. |
Fill in the missing words in the following paragraph:
A female needs _____ copies of a recessive X-linked allele to express the trait, while a male only needs _____. This is because males are _______ for the X chromosome. Traits that are controlled by genes on the X or Y chromosome are called _______ traits. A common example is ________.
Explain why sex-linked traits are more commonly expressed in males than in females. Use specific examples to support your answer.
Please log in to post your answer.
Log InEarn 2 Points for answering. If your answer is selected as the best, you'll get +20 Points! 🚀