What do all vertebrates and invertebrates have in common? they are prokaryotic. they are covered by an outer skeleton. they are multicellular. they are bilaterally symmetrical.

Ans. 'They are multicellular.'

Invertebrates are lower eukaryotic organisms that lack presence of vertebral column (backbone), such as poriferans, annelids, mollusk, arthropods. They may be symmetrical or asymmetrical.

Vertebrates are higher eukaryotic organisms that have vertebral column, derived of notochord. These organisms include fishes, reptiles, birds, mammals, and amphibians. Exoskeleton is not present in all vertebrates.

The common characteristic shared by both invertebrates and vertebrates is multicellularity as both are made up of more than one types of cells.

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.