Please Help! Pedigree Lab in High School?

  • Thread starter Thread starter Michael
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Michael

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Hi, I do not know what the + or - sign means when it comes to a (Aa + -).
I am doing a pedigree lab in high school for AP Bio and I'm very confused what this means. It has something to do with a non recombinant offspring or recombinant offspring. Example: aa -/- mates with Aa +/- makes aa -/-. what do the plus and negative signs mean?
I apologize for not adding.
I see aa +-.
And I see Aa -- for the Recombinant offspring
I also see aa ++
 
I'm assuming the + and - signs are your teacher's way of showing you the genotypes given (dominant/recessive/heterozygous).
AA (++) - homozygous dominant
aa (--) - homozygous recessive
Aa (+-) - heterozygous
So... given that... then a homozygous recessive (aa --) mating with a heterozygous (Aa +-) would give you a ratio of 3:1 - three homozygous recessive and one heterozygous.
 
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