Lymphocytes that are clones of activated B cells or T cells that enhance resistance to future infection are called:
a. memory cells.
b. clones cells.
c. enhanced cells.
d. recall cells.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.