AP BIOLOGY

Detailed explanation-1: -When true-breeding, or homozygous, individuals that differ for a certain trait are crossed, all of the offspring will be heterozygous for that trait. If the traits are inherited as dominant and recessive, the F1 offspring will all exhibit the same phenotype as the parent homozygous for the dominant trait.

Detailed explanation-2: -The risk will be the same for every birth. If both parents have a heterozygous dominant mutation, their children have a 50% chance of getting the dominant allele (partial or complete symptoms), a 25% chance of getting both dominant alleles (symptoms), and a 25% of getting both recessive alleles (no symptoms).

Detailed explanation-3: -A testcross to a heterozygous individual should always yield about a 1:1 ratio of the dominant to recessive phenotype. So, both the genotypic and phenotypic ratios here are 50:50.

Detailed explanation-4: -The answer has to do with the fact that each parent actually has two different sets of genes. And that each parent passes only half of their genes to their child. And that the half that gets passed down is random. All of this together ensures that each child ends up with a different, unique set of genes.

Detailed explanation-5: -If two heterozygotes are crossed, the probability that an offspring will show the dominant trait is 75% or 0.75. The probability that an offspring will show the recessive trait is 25% or 0.25.