The answer to your question is D. Heat Transfer
Bacteria are single celled prokaryotic organisms. Prokaryotic means that they do not contain membrane-bound organelles. In simpler terms, they don't have cell parts within their cytoplasm. Bacteria are classified by their shape- round or cocci, rod or bacilli, and spiral or spirilla. Bacteria may also have long whip-like tails called flagella or be covered with small hair-like projections called cilia. Both structures are used for movement. Bacteria may have a cluster of free floating DNA in its cytoplasm called a nucleoid or they may have additional small rings of DNA called plasmids. Lastly, a bacterium have a cell wall made of a special compound called peptidoglycan which can provide an extra layer of protection from many environmental conditions.
Answer:
Cells
Explanation:
Cells are the smallest living unit, but atoms are the smallest unit of the above choices... Cells are made of atoms... But you asked about the Smallest unit of life so I don't know if you are asking about the smallest unit ever or the smallest unit in the living things
