Vaccines help develop immunity by imitating an infection, but this “imitation” infection does not cause illness. It does, however, cause the immune system to develop the same response as it does to a real infection so the body can recognize and fight the vaccine-preventable disease in the future
Answer:
phase change requires more energy to occur
Answer:
The cell is the smallest structural and functional unit of living organisms, which can exist on its own. Therefore, it is sometimes called the building block of life. Some organisms, such as bacteria or yeast, are unicellular—consisting only of a single cell—while others, for instance, mammalians, are multicellular.
Explanation:
Answer:The above statement is "false".
Explanation:
The following events take place during contraction-relaxation of a muscle:
•Action potential in T tubule activates voltage-sensitive receptors,which in turn trigger Ca ions release from terminal cisternae of sacroplasmic reticulum(SR) into cystol.
•Ca ions bind to troponin;troponin changes shape,removing the blocking action of tropomyosin;actin active sites is exposed.
•CONTRACTION; myosin heads alternatively attach to actin and detach,pulling the actin filaments toward the center of the sarcomere;using ATP in this process.
•removal of Ca ions by active transport into the SR after the action potential ends.
•RELAXATION occurs.Actin and myosin return back to its unbound state.
