Question

in humans, a widows peak (h) is dominant to a straight hair line (h). complete the pedigree below and answer the following questions. a: how many generations are shown in the pedigree above? b. which individuals have a widows peak? c. which individuals have a straight hair line? a: 3; b: i-1; ii-1; ii-4; iii-2; c: i-2; ii-2; ii-3; iii-1 a: 3; b: i-2; ii-2; ii-3; iii-1; c: i-1; ii-1; iii-2

Explanation:

Step1: Analyze Generation Count

In a pedigree, generations are numbered from top (oldest) down. The topmost is Generation I, then II, then III. So there are 3 generations.

Step2: Identify Widow's Peak (Dominant, H)

Widow's peak is dominant, so shaded symbols (assuming shaded = widow's peak) are I-1 (shaded square), II-1 (shaded circle), II-4 (shaded circle), III-2 (shaded square).

Step3: Identify Straight Hair Line (Recessive, h)

Straight hair line is recessive, so unshaded symbols: I-2 (unshaded circle), II-2 (unshaded square), II-3 (unshaded square), III-1 (unshaded circle).

Step4: Match with Options

The first option has A:3, B: I-1; II-1; II-4; III-2, C: I-2; II-2; II-3; III-1, which matches our analysis.

Answer:

A: 3; B: I-1; II-1; II-4; III-2; C: I-2; II-2; II-3; III-1