Please explain, and no hand-written work please, please type answer
Sex-Linked Traits (traits located on the sex chromosomesâusually the X chromosome)
Follow the directions for the lab. Enter data you obtain for the following crosses and answer questions on this answer sheet. (NOTE: The traits used in this Module 3 Lab are sex-linked. Therefore, you CANNOT click the âignore sexâ button for these crosses. You need to see separate results for males and females to analyze data for sex-linked traits.)
Question: In this lab exercise, should you click the "ignore sex" button for the crosses?
1. a. Perform a monohybrid cross between a female fly with a tan body and a wild-type male fly. Show results for the F1 offspring. (NOTE: You will use these F1 flies in the next cross.)
ENTER DATA HERE:
Question: Are the phenotypes of the F1 offspring what you would have predicted for this cross: why or why not?
Question: Each F1 female received a tan allele from her mother and a wild allele from her father. Why do all of the F1 females show the wild-type phenotype?
Question: Compare the number and type (X or Y) of sex chromosomes found in female and male flies.
Question: Compare the number of alleles present on the X and Y chromosomes.
Question: How can you tell that tan body is a sex-linked trait?
Question: How can you tell whether tan body is located on the X chromosome or the Y chromosome?
Question: If tan body was located on the Y-chromosome, what would be the phenotype of all the male F1 offspring? Is this what you obtained for the cross above?
Question: If tan body was located on the Y-chromosome, could females even show the trait? (HINT: When analyzing the cross results, remember that Y-linked traits are passed down only from affected males to their sons. Females cannot display Y-linked traits since they do not have Y chromosomes. On the other hand, both males and females can inherit X-linked traits since they both have X chromosomes.)
PUNNETT SQUARE:
List the genotypes of the parent flies in this cross (HINT: You must use X and Y symbols):
List the gametes produced by each parent fly in this cross:
Show the Punnett Square for the above cross.