AP BIOLOGY

Detailed explanation-1: -Pheromones are chemical signals that have evolved for communication between members of the same species. A pheromone signal elicits a specific reaction in the receiver, for example, a stereotyped behavior (releaser effect) or a developmental process (primer effect). Some pheromones can have both effects.

Detailed explanation-2: -In most mammals, pheromones usually are detected by a specialized organ inside the nose or mouth called the vomeronasal organ, or VNO. Nerves connect it to parts of the brain involved in reactions rather than cognition. In humans, the organ appears in embryos with its nerve cells extending into the developing brain.

Detailed explanation-3: -The pheromone consists of an aromatic compound (2-phenylundecane), cuticular hydrocarbons (pentacosane and heptacosane), fatty acids (palmitic acid and trans-vaccenic acid), and cholesterol; the pheromone induces long-term aggregation at new nesting and feeding sites.

Detailed explanation-4: -Bees, wasps, ants, moths and other insects rely largely upon pheromones as a means of communication. Pheromones are chemical substances which may be secreted in urine, dung or produced by special glands. They are usually given off by the female of the species to attract males.