The outer ring is is the ever first ring but the inner ones tell if it’s old or not.
Speciation is not a mechanism of microevolution.
Males have XY and females have XX
Answer:
B. Shortens
Explanation:
Myofibrils are components of the animal skeletal muscles that are made up of sacromeres. They perform the muscular contraction and relaxation via the sliding filament model.
To produce motion, A cross-bridge forms between actin and the myosin heads triggering shortening of the sacromere. This shortening of the sacromere results in the contraction of the muscle fibers, which the net effect can be seen to be a shortening of the fibers