The mother because it is an x-linked trait and the boy received a y from his father so therefore he could only get the x from his mother.
Protein is the nutrient that is essential to cellular construction, reproduction, and maintenance.
Answer:
Cost: competition for mates, competition for resources
Benefit: better protection from predators (ex. a fish in a school of fish has greater chances of not getting eaten because of the large number of other fish)
Answer:
Stomach mucus protects the gastrointestinal cells from the damage that gastric juices can cause. Gastric juices are very acidic and without the mucus, the acid can destroy the cells and tissues inside the stomach.
