It is generally acknowledged that as human beings age, it becomes more difficult for them to lose weight, or even maintain their current weight. People find they have to eat less and/or exercise more to maintain a healthy weight. Which is the most likely explanation of why weight loss/maintenance becomes more difficult as people age?

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

the answer is c.mitochondria. glad to .

well the answer is 2!