Final answer:
Features of dominant inheritance in a pedigree include the trait appearing in every generation and affected individuals usually having at least one affected parent. Pedigree charts denote this with shaded symbols, and Punnett squares help predict if an individual is homozygous or heterozygous for the dominant trait.
Step-by-step explanation:
Features indicating dominant inheritance in a pedigree include the appearance of the trait in every generation and affected individuals having at least one affected parent. This is opposed to recessive inheritance, where the trait can skip generations and unaffected parents can have affected offspring if both are carriers. In the context of dominant traits, when a trait does not skip any generation, it suggests that only one copy of the allele is needed for the trait to be expressed. Affected individuals on a pedigree chart will often be represented by a shaded circle (female) or square (male) and typically show the trait in question, even if they have just one affected parent.
To elaborate, considering the examples of dominant and recessive phenotypes given in Figure 1, in the case of a dominant phenotype, such as a cleft chin (represented by Figure 3.5), children who have the trait will typically have at least one parent with the trait as well. This is seen in a Punnett square, which helps us predict the inheritance pattern (as shown in Figure 3.5(a)). Dominant alleles are denoted by a capital letter (B for cleft chin), and the presence of this dominant allele results in the expression of the dominant trait.
Use of a Punnett square can also help determine if an organism expressing the dominant trait is a homozygote or a heterozygote for that trait, as described in Figure 12.5. This leads us to another feature of dominant inheritance: heterozygote individuals (carriers of one dominant and one recessive allele) can express the dominant phenotype. If we look at Table 12.4, we can further categorize human inheritance traits into dominant versus recessive patterns.