If A + B means A is the mother of B; A - B means A is the brother of B; A % B means A is the father of B, and A \(\times\) B means A is the sister of B, which of the following shows that P is the maternal uncle of Q?
Let's break down each part of the statement and explain how we arrive at the conclusion:
1. P - M → P is the brother of M This statement tells us that P is the brother of M. In other words, P and M share the same parents, and they are siblings. This sets up the relationship that P is a male (brother) and M is also a sibling.
2. M + N → M is the mother of N This means that M is the mother of N. We now know that M (who is the sister of P, from the first statement) has a child N, and therefore, M is a female, specifically a mother.
3. N × Q → N is the sister of Q This tells us that N is the sister of Q. Therefore, N and Q are siblings, and N is female.
4. Conclusion: P is the maternal uncle of Q Given the relationships: P is the brother of M (from statement 1).
M is the mother of N (from statement 2), and N is the sister of Q (from statement 3).
Since M is Q's mother, P, being M's brother, is the maternal uncle of Q.
The term "maternal" refers to the mother's side of the family, so P is the brother of Q's mother, making him Q's maternal uncle.
Therefore, option (3) correctly shows that P - M + N \(\times\) Q
In nearly all human populations a majority of individuals can taste the artificially synthesized chemical phenylthiocarbonide (PTC). However, the percentage varies dramatically from as low as 60% in India to as high as 95% in Africa. That this polymorphism is observed in non-human primates as well indicates a long evolutionary history which, although obviously not acting on PTC, might reflect evolutionary selection for taste discrimination of other, more significant bitter substances, such as certain toxic plants.
A somewhat more puzzling human polymorphism is the genetic variability in earwax, or cerumen, which is observed in two varieties. Among European populations 90\% of individuals have a sticky yellow variety rather than a dry, gray one, whereas in northern China these numbers are approximately the reverse. Perhaps like PTC variability, cerumen variability is an incidental expression of something more adaptively significant. Indeed, the observed relationship between cerumen and odorous bodily secretions, to which non-human primates and, to a lesser extent humans, pay attention suggests that during the course of human evolution genes affecting body secretions, including cerumen, came under selective influence.
In nearly all human populations a majority of individuals can taste the artificially synthesized chemical phenylthiocarbonide (PTC). However, the percentage varies dramatically from as low as 60% in India to as high as 95% in Africa. That this polymorphism is observed in non-human primates as well indicates a long evolutionary history which, although obviously not acting on PTC, might reflect evolutionary selection for taste discrimination of other, more significant bitter substances, such as certain toxic plants.
A somewhat more puzzling human polymorphism is the genetic variability in earwax, or cerumen, which is observed in two varieties. Among European populations 90\% of individuals have a sticky yellow variety rather than a dry, gray one, whereas in northern China these numbers are approximately the reverse. Perhaps like PTC variability, cerumen variability is an incidental expression of something more adaptively significant. Indeed, the observed relationship between cerumen and odorous bodily secretions, to which non-human primates and, to a lesser extent humans, pay attention suggests that during the course of human evolution genes affecting body secretions, including cerumen, came under selective influence.