[Solved] ____________________is a reversible form of dementia,while the major symptom of depression is____________________,which is when a person feels down or blue. Selfish Herd Hypothesis: A theory suggesting that individuals can reduce their predation risk by positioning themselves within a group, thus exploiting the protection offered by the collective. Assassin Bug: A member of the Reduviidae family, known for their predatory behavior and method of injecting toxic saliva into their prey. Sleeping Cluster: A behavior observed in some animals, including naked mole rats, where individuals sleep closely together for warmth, safety, or social bonding. Peripheral: Relating to or situated on the edge or outer limits of something, often used to describe objects or areas that are not central or core to a main subject.