A test cross can be used to determine the genotype of the parent (whether it is homozygous or heterozygous for a specific trait). AA x aa = all Aa offspring, dominant phenotype.
<span>Aa x aa = 1/2 Aa dominant and 1/2 aa recessive
A population decrease in primary producers would affect the ecosystem negatively because everyone who ate the primary consumers would have a lack of food.
