In horses, trotter (T) is dominant to pacer (t), and black coat color (B) is dominant to brown (b). A black horse who is a pacer mates with a brown horse who is a trotter. The resulting foal is a brown pacer. Give the genotypes of all three horses. Show work.
Black pacer parent:
Brown trotter parent:
Brown pacer foal:
Black pacer parent:
Brown trotter parent:
Brown pacer foal:
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Start with what you know. The foal is recessive for both genes, therefore can have only one genotype
bbtt, it is brown - homozygous recessive and a pacer homozygous recessive.
The black pacer parent is recessive for pacing tt. It passes on a b allele to its foal, but is black, so must have genotype Bb. Overall Bbtt.
The brown trotter is the reverse, bb for colour, but passes on a t allele to the foal despite being a trotter itself, therefore Tt. Overall bbTt.
bbtt, it is brown - homozygous recessive and a pacer homozygous recessive.
The black pacer parent is recessive for pacing tt. It passes on a b allele to its foal, but is black, so must have genotype Bb. Overall Bbtt.
The brown trotter is the reverse, bb for colour, but passes on a t allele to the foal despite being a trotter itself, therefore Tt. Overall bbTt.