Explain codominance, prepotency, atavism, and chromosomal mutations, and provide examples of mutagenic agents.

2.2.2. In codominance, both alleles for a trait are expressed equally and distinctly in the heterozygote, resulting in a phenotype that shows characteristics of both homozygous parents, such as the roan coat color in cattle where both red and white hairs are present.

2.3.1. Prepotency is important in genetics because it describes the ability of a parent to consistently pass on its traits to its offspring. This concept is crucial in selective breeding programs to ensure desired characteristics are inherited reliably.

2.3.2. Atavism is important as it demonstrates the persistence of ancestral genes within a species' genome. The reappearance of a trait after many generations indicates that the genetic information for that trait was retained, even if it was not expressed.

3.1.1. The type of mutation represented in the diagram is a chromosomal mutation.

3.1.2.

• A gene mutation is a change in the nucleotide sequence of a single gene.
• A chromosomal mutation involves changes in the structure or number of entire chromosomes.

3.1.3. Two mutagenic agents are:

• Ionizing radiation (e.g., X-rays, gamma rays)
• Certain chemicals (e.g., ethidium bromide, mustard gas)