0% because if straight hairline is recessive that means it would need 2. Since, Widows peak seems to be dominant, then there would need to be at least 1 dominant. But, there are both people that have recessive traits.
In the topographic classification, diseases<span> are subdivided into such categories as gastrointestinal </span>disease<span>, vascular </span>disease<span>, abdominal </span>disease<span>, and chest </span>disease<span>. ... In the anatomic classification, </span>disease<span> is </span>categorized<span> by the specific organ or tissue affected; hence, heart </span>disease<span>, liver </span>disease<span>, and lung </span>disease<span>.</span>