Final answer:
Autosomal dominant inheritance occurs when an individual has at least one dominant allele, sex-linked inheritance is usually recessive with more affected males, and multiple alleles refer to genes with more than two possible alleles.
Step-by-step explanation:
There are different inheritance patterns within each allele type.
- Autosomal dominant inheritance occurs when an individual has at least one dominant allele. Affected individuals can be either homozygous dominant or heterozygous. For example, if a parent with free-hanging earlobes (dominant trait) has a child with attached earlobes (recessive trait), the child must have inherited the recessive allele from the other parent.
- Sex-linked inheritance is usually recessive, with more males (XY) than females (XX) having the trait. One example is color blindness, which is a recessive X-linked trait. Since males have only one X chromosome, if they inherit the trait, they will express it. Females, on the other hand, need to inherit the trait from both parents to express it.
- Multiple alleles refers to a gene with more than two possible alleles. An example is the ABO blood group system, where there are three alleles: A, B, and O. Each person inherits two alleles, resulting in different blood types.