Question

Using a pedigree, show an autosomal recessive disorder pattern and an autosomal dominant disorder pattern. (pages \(474-75\) )

Short answer

An autosomal recessive disorder pattern can be represented in a pedigree as follows: ``` I II III 1 2 1 2 3 4 1 2 3 4 5 6 □□ □□ □□ □□ □ □□ □□□ □ ``` Here, individuals II-4 and III-6 have the autosomal recessive disorder represented by a shaded symbol. An autosomal dominant disorder pattern can be represented in a pedigree as follows: ``` I II III 1 2 1 2 3 4 1 2 3 4 5 6 □□ □ ■ □ □ ■ □ □ □ □ ■ ``` In this pedigree, individuals II-2, III-1, and III-6 have the autosomal dominant disorder represented by a shaded symbol.

Step-by-step solution

Understand autosomal recessive inheritance

Autosomal recessive inheritance is when two copies of an abnormal gene must be present in the offspring for the disorder to manifest. This means that individuals carrying only one copy of the abnormal gene (heterozygous carriers) do not exhibit symptoms or signs of the disease. Step 2: Construct a pedigree for an autosomal recessive disorder

Construct a pedigree for an autosomal recessive disorder

To show an autosomal recessive disorder pattern using a pedigree, we will use the following symbols: squares for males, circles for females, and a shaded shape representing individuals with the disorder. The generations are labeled using Roman numerals (I, II, III, etc.), and the individuals within each generation are labeled using Arabic numerals (1, 2, 3, etc.). An example of a pedigree for an autosomal recessive disorder is as follows: ``` I II III 1 2 1 2 3 4 1 2 3 4 5 6 □□ □□ □□ □□ □ □□ □□□ □ ``` In this pedigree, individuals II-4 and III-6 have the autosomal recessive disorder represented by a shaded symbol. Step 3: Understand autosomal dominant inheritance

Understand autosomal dominant inheritance

Autosomal dominant inheritance is when only one copy of an abnormal gene is required for the disorder to manifest in the offspring. This means that individuals can inherit the abnormal gene from either parent, and a parent with the disorder has a 50% chance of passing the gene to each of their children. Step 4: Construct a pedigree for an autosomal dominant disorder

Construct a pedigree for an autosomal dominant disorder

To show an autosomal dominant disorder pattern using a pedigree, we will use the same symbols as in the autosomal recessive example: squares for males, circles for females, and a shaded shape representing individuals with the disorder. An example of a pedigree for an autosomal dominant disorder is as follows: ``` I II III 1 2 1 2 3 4 1 2 3 4 5 6 □□ □ ■ □ □ ■ □ □ □ □ ■ ``` In this pedigree, individuals II-2, III-1, and III-6 have the autosomal dominant disorder represented by a shaded symbol.