Chromosome #3 contains the "S" gene. This gene controls the shape of the chin, round or square. These genes are activated only if the dominant "L" on chromosome #2 is present. Place your baby's genotype for chin shape in the data table. The control of one set of genes by another is called epistasis.
	Chromosome #5 carries the "C" gene. The "C" gene controls the development of the cleft chin phenotype. Remember these "C" genes are activated only if the dominant "L" on chromosome #2 is present. Place your baby's genotype for chin shape in the data table. The control of one set of genes by another is called epistasis.

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