SWIMMERETS in the crayfish are the paired ventral abdominal appendages which beat in a metachronal rhythm during behaviours such as swimming and burrow ventilation. Each swimmeret is driven by alternating bursts of impulses in antagonistic power- and return-stroke motoneurones. Why do crayfish have Swimmerets? Tell the students that the swimmeretsRead More →

Joint hypermobility, which affects approximately 20 percent of the population, confers an unusually large range of motion. Hypermobile people can often, for instance, touch their thumb to their inner forearm or place their hands flat on the floor without bending their knees. How do you tell if you’re double jointedRead More →