Humans feel hungry when their empty stomachs contract and when glucose levels in the blood drop. Both of these situations stimulate neurons that send messages to the brain which are interpreted as hunger. What body systems are
involved in this process as described?

digestive, muscular, integumentary, and respiratory

digestive, excretory, integumentary, and respiratory

circulatory, excretory, nervous, and skeletal

circulatory, digestive, muscular, and nervous

Monarch butterflies have brightly colored orange wings with black patterns on them, making them easily visible to birds that eat butterflies and moths, yet birds rarely eat the monarchs. likewise, the monarch caterpillars are brightly striped yellow and white and black, and they also are rarely eaten by birds, although some wasps will attack them and feed them to their young. what can be inferred from these observations? monarchs must threaten and attack birds, but not wasps. monarchs have a way of discouraging bird predation that does not involve hiding. monarchs’ wings are so colorful that most birds must find them difficult to eat. monarchs lay more eggs than other less conspicuous butterflies.