Sex-linked inheritance has to do with traits that are determined by genes located on the sex chromosomes. Sex chromosomes are the pair of chromosomes, usually designated X or Y, in most animals and some plants that determine the sex of an individual. The chromosome combination of XX results in a female while the XY combination results in a male.
Genes that are found on the X chromosome are called X-linked genes. Both females and males can inherit these traits. Sex-linked traits typically have two alleles for a particular trait, one dominant allele and one recessive allele. The phenotype may be masked in females if one of the X chromosomes contains a dominant gene for the trait. Since males only have one X chromosome, the recessive trait will be expressed if they inherit a recessive allele for a trait.
Watch this video to learn more about sex-linked traits, and see how offspring are predicted using Punnett squares.
Complete the following chart by giving the phenotypes and genders for the following genotypes, XC gene for normal vision and Xc gene for color blindness.
GENOTYPE | PHENOTYPE | GENDER |
XCXC | Check Your Answer Normal | Check Your Answer Female |
XCY | Check Your Answer Normal | Check Your Answer Male |
XCXc | Check Your Answer Normal (carrier) | Check Your Answer Female |
XcY | Check Your Answer Color blind | Check Your Answer Male |
XcXc | Check Your Answer Color blind | Check Your Answer Female |