[For Elementary School Students] 3-Choice Quiz to Deepen Knowledge of Living Things

Only one side moves

A crab’s claws are set up so that one side is fixed and doesn’t move, while only the other side moves. Crabs use these claws to catch food and tear it into bite-sized pieces. Incidentally, a crab’s claws are considered legs, not hands.

chin

The pincers that male stag beetles have correspond to their jaws. They are used to grapple with and overpower other males during fights, and when competing over territory. Well-developed pincers are a symbol of strength and an important factor in winning mates.

whale shark

The whale shark got its name because the pattern on its body resembles a traditional Jinbei haori. Although it has a large body, it feeds on tiny plankton. It is gentle by nature, does not attack people or large fish, and can be rather timid.

Flying

Rhinoceros beetles have large bodies and small wings, so they’re not good at flying. Basically, they don’t move much from where they are unless another insect takes over their feeding spot. Even when they do fly, they’re slow and can’t compete with insects like dragonflies.

has a backbone

Humans have a fixed number of 24 vertebrae, but fish do not have a set number. Fish also have more bones than humans—for example, they have three just in the jaw, and several dozen in the fins. By the way, if a fish bone gets stuck in your throat, gargling is recommended as a first step.

dolphin

The correct answer is “dolphin.” Sharks are fish that belong to the class of cartilaginous fish, differing from other fish in that their skeletons are made of cartilage. Meanwhile, the ocean sunfish lives in tropical and subtropical seas; although it has an unusual shape, it is a type of fish. However, dolphins are not fish but mammals. Dolphins have characteristics unique to mammals, such as breathing with lungs and nursing their young with milk.

puff up one's body

Pufferfish puff up their bodies when they feel threatened or stressed. One theory about the origin of their Japanese name, “fugu,” comes from this puffing behavior. They are also written as “河豚” in kanji because their swollen appearance was thought to resemble a pig.