Which of the following characteristic would a plant, a human being, and a flatworm share? a. they all exchange gases with the environment. b. they all undergo photosynthesis. c. they all have a digestive system that breaks down food. d. they all use a muscular system for movement.

A. They all exchange gases with the environment.

Explanation:

The plants, humans and flatworm are the complex eukaryotic organisms which performs a vital function of respiration. In respiration the carbon dioxide gas is expelled out of the body whereas the oxygen is taken inside the body. In plants the exchange of gases takes place through tiny pores called as stomata. In humans the exchange of gas occurs through complex organs like skin, and nose. In flatworm the exchange of gases takes place through the tiny pores present on the outer membrane of the body.

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.

not only is it colder, it also becomes darker, less salty, and more dense.