Photosynthesis is a process used by plants and other organisms to convert light energy into chemical chemical energy that can later be released to fuel the organisms activities.
Answer:
two objects with the same electric charge rub together
Explanation:
Answer:
Adaptive immunity also involves a memory to provide the host with long-term ... Unlike NK cells of the innate immune system, B cells (B lymphocytes) are a ... Cytotoxic T cells destroy virus-infected cells in the cell-mediated immune ... Helper T- cells are one of the main lymphocytes that respond to antigen-presenting cells.
Explanation:
To prevent the backflow of blood during systole and diastole, Artries from the heart dont need valves since their blood pressure is already high enough to not allow backflow of blood, but since veins' blood pressure is lower, they need valves just so the blood doesn't seep back in into the heart again!