Download presentation
Presentation is loading. Please wait.
1
Patterns of Inheritance sex linked traits
2
Review How many chromosomes do each of our cells have? 46
Do all of these chromosomes have the same function, or do they all serve a different purpose? They are different; each individual chromosome has specific proteins that control certain traits.
3
Chromosomes 46 chromosomes are found in each of our cells.
22 pairs of autosomes (body chromosomes) 1 pair of sex chromosomes (XX or XY) * Remember * Males and Females have two different sex chromosomes Males = XY Females = XX
4
Sex Chromosomes The X chromosome carries a variety of genes that are necessary for the development of both females and males. The Y chromosome mainly has genes that relate to the development of male characteristics.
5
Sex-Linked Traits So far, all of the traits that we have discussed are found on the autosomes. Any gene that is carried on either the X or Y chromosome in known as a sex-linked gene. Therefore, the trait that is shown due to this gene is called the sex-linked trait. Most sex-linked traits (or diseases) are carried on the X chromosome. Very few are carried on the Y chromosome.
6
Notation for sex-linked traits
If the majority of sex-linked traits/diseases are carried on the X chromosome, who is more likely to be affected? Males or Females Since males have only one X chromosome, they are affected by recessive X-linked traits more often than females. This time we have to show the chromosomes. R = Red Eyes r = White Eyes XRXR = Red Eyes XRXr = Red Eyes XrXr = White Eyes XRY = Red Eyes XrY = White Eyes
7
Dominant or Recessive Sex-linked traits can still be dominant or recessive. XRXR = Homozygous Dominant XRXr = Heterozygous XrXr = Homozygous Recessive XRY = Dominant XrY = Recessive
8
Examples of Sex-Linked Traits
Red-Green color blindness Insensitive to green and purplish-red ~ 8% of males in the U.S. have red-green color blindness
9
How is it passed on?
10
Are you color blind?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.