Question

For humans, freckles and broad noses are dominant to no freckles and narrow noses. Use the pinned square below to determine the possible offspring from a cross between two heterozygous freckles broad nose people

Answer 1

If we name the gene for freckles with F, then the genotypes for having freckles are Ff (heterozygous), FF (dominant homozygous) and for no freckles ff (recessive homozygous).

If we name the gene for nose shape with N, than the genotypes for broad noses are NN (dominant homozygous) and Nn (heterozygous) and for narrow noses nn (recessive homozygous). A cross between two heterozygous:

P: FfNn  x  FfNn

F1:

9/16 are with freckles and broad noses

3/16 are with freckles and narrow noses

3/16 are with no freckles and broad noses

1/16 are with no freckles and narrow noses.