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.
If knee is in full extension rotation is restricted by interlocking of condyes with tibia â¢ Rotation increases as the knee is flexed â maximum 90 0 flexionflexion â¢ External 45 0 â¢ Internal 30 0 â¢ Beyond 90 0 â decreases, due to soft tissue restriction.