I Need Help understanding gametes, genotypes and phenotypes

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    • #17602

      I am having trouble understanding how to figure out the ratio of genotypes and phenotypes.
      The question says: There is an allele E which codes for unattached earlobes in humans. The allele e codes for the attached earlobes which do not hang free. If a ee male marries a Ee female what gametes could each parent produce? Father: Mother:

      Second part of the question is: what possible genotypes could their children have? What possible Phenotypes?

      I did a punnet square with Ee and ee to find the gamestes but I got the same answer for the second part of the question. Help me please im so confuse.

    • #114644

      I do not know how to go about this question. A man who has type AB blood marries a women with type B blood (her genotype is I^Bi). What phenotypes and genotypes of children could they produce.

      Would I do a punnet square with AB and Ii?

    • #114648

      The first question isn’t about offspring, it’s just about gametes. You don’t need to draw a punnett square until the second question. You’re doing more work than it is asking you to do.

      Post Two:
      lowercase i is recessive and uppercase I is dominant, but there are actually two codominant alleles. I^A is dominant allele for type A, and I^B is dominant allele for type B.
      There is only an exception if the have the Bombay phenotype, which involves alleles (denoted h & H) in another part of the genome.

      quote :

      Individuals with the rare Bombay phenotype (hh) do not express H antigen (also called substance H), the antigen which is present in blood group O. As a result, they cannot make A antigen (also called substance A) or B antigen (substance B) on their red blood cells, whatever alleles they may have of the A and B blood-group genes, because A antigen and B antigen are made from H antigen.


    • #114653

      so the first would have gametes of Ee, ee for the female and male

      and the second question is a doing a punnet square with I^A and I^B with I^Bi

    • #114654

      I am still not understanding the second question i don’t know how to put the punnet square together

    • #114707

      no, gametes are haploid, so it can be either E or e

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