Knees should point same direction as feet throughout movement. Heel of rear foot can be kept elevated off floor throughout movement as shown. Keep torso upright during squat; flexible hip flexors are important. With feet further apart: Gluteus Maximus is emphasized, Quadriceps are less emphasized. Also known as Cable Lunge.
Quick look: Found only in animal cells and some lower plants, a centriole is composed of short lengths of microtubules lying parallel to one another and arranged around a central cavity to form a cylinder. centriole is composed of short lengths of microtubules arranged in the form of an open-ended cylinder about 500nm long and 200nm in diameter.
Centrioles are built from a cylindrical array of 9 microtubules, each of which has attached to it 2 partial microtubules. The photo (courtesy of E. deHarven) is an electron micrograph showing a cross section of a centriole with its array of nine triplets of microtubules. Some attach to one kinetochore of a dyad with those growing from the opposite centrosome binding to the other kinetochore of that dyad. 2  Some bind to the arms of the chromosomes. 3  Still others continue growing from the two centrosomes until they extend between each other in a region of overlap.