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These sterile female ants perform most colony tasks including foraging, nursing, and nest maintenance.
Difficulty: EasyThis large-eyed, round-faced bird appears on the Hogwarts crest and delivers mail in the Harry Potter series.
Difficulty: MediumThis dominant gene suppresses pigment in the hair shaft, producing silver tabbies, smoke, and chinchilla coat patterns.
Difficulty: HardThis three-horned giant's skull could reach nearly 10 feet long, making it one of the largest heads ever to walk the Earth, yet it was strictly a plant-eater that used its horns primarily for defense against predators.
Difficulty: EasyThis term describes dogs bred by crossing two different purebred breeds, such as a Labradoodle or Goldendoodle.
Difficulty: MediumWhen experimental removal of the clock gene per abolishes circadian rhythms in Drosophila, this demonstrates the molecular basis of this mechanism.
Difficulty: HardThis buzzing insect produces honey and lives in hives with a queen, workers, and drones.
Difficulty: EasyThis social structure, where only one female in a group breeds, is seen in naked mole rats and some wolf packs.
Difficulty: Medium