DNA is extracted from human cells for a variety of reasons. With a pure sample of DNA you can test a newborn for a genetic disease, analyze forensic evidence, or study a gene involved in cancer.Try this virtual laboratory to perform a cheek swab and extract DNA from human cells.Javascript is required to view this content.ith a pure sample of DNA you can test a newborn for a genetic disease, analyze forensic evidence, or study a gene involved in cancer. Try this virtual laboratory to perform a cheek swab and extract DNA from human cells. Javascript is required to view this content.
Knee flexion means bending your leg at the knee joint, reducing the angle between your lower leg and upper leg.
People who sit or lie with their knee flexed for extended periods of time may develop knee flexion contractures. To maintain normal function and subsequent motion in the joints, soft tissues, muscles and ligaments affected by a flexion contracture, perform range-of-motion exercises throughout the day.