Phenotype/genotype ratio & sex-linked + autosomal help (1 Viewer)

[pilota45]

If the questions asks for what is the phenotype/genotype ratio, would you write in percentages or in numbers then simplified? For example, the offspring have genotypes Hh, Hh, hh and hh, would the genotype ratio be 2Hh:2hh or 1Hh:1hh or 50%Hh:50%hh?

Also, does anyone have any tips on how to identify whether a disease is autosomal or sex-linked quickly in an exam, or praticing is the best way to pick up the pace.

 

[pikachu975]

I think either numbers or percentages is fine

To see that it is NOT sex linked, a daughter would have the disease and the father wouldn't. But this stuff comes from practice so you gotta do a lot of questions

 

[HeroWise]

Yeah,

Start from this: 1) X linked recessive- Mother has it then all the sons have it, or , daughter has it and the father has it
2) Auto recessive- Parents dont have it but their child do
3) Codominant: If there are more than 2 keys
4) X linked dom: IF the father has it, all the daughter must have it
5) Dom: PResent in every gen, Parents have it but child dont