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.
Range-of-motion exercises can help improve a flexion contracture in your knee. People with a flexion contracture of their knee joint can experience mobility problems due to a flexed knee. A flexion contracture occurs when the tissues in your knees thicken after a period of immobilization and prevent your knee from bending. Range-of-motion exercises can help improve movement in your knee joint.