Which of the following characteristics of eukaryotic cells is used to support the theory that they evolved from the union of free-living cells? A. The ability to transport materials across a membrane
B. The presence of mitochondrial DNA
C. Reproduction by mitotic cell division
D. Differentiation of stem cells into specialized cells

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.