The first multicellular animal to evolve were invertebrates. Why have so few fossils of these organisms been found? A. Their soft bodies do not fossilize well.

B. There were very few species alive long ago.

C. High rates of predation forced many to extinction before they could be preserved.

D. Conditions were not right for preservation at the time when they lived.

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.

because the light is a great source of energy for the plants to survive. (i hope this )

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.