Where does energy first come into an ecosystem? A producers make energy
B the sunlight provides energy to producers
C consumers obtain energy from animals
D scavengers obtain energy from dead plants

B. Sunlight provides energy to producers

Explanation: photoautotrophs (plants) produce energy from sunlight by photosynthesis. This is the only energy production based on an external source of energy. Plants, whether alive or dead, are consumed by heterotrophs - bacteria, fungi and animals. The nutrients and energy from dead heterotrophs (and some live ones) are recycled by both autotrophs and heterotrophs.

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.