Answer:
A group of bacteria that accumulate in layers and secrete a protective extracellular material. (Option A)
Explanation:
Biofilm is defined as one or more types of microorganisms collectively grow in different places. Organisms that form the biofilm include protests, fungi, and bacteria.
Dental plaque is an example of a biofilm. It is a known buildup of slimy bacteria that forms on the teeth surface. Biofilm can grow on different surfaces such as animal tissues, plant tissues, minerals, metal, etc.
<h2>Answer:</h2>
Carbon
<h2>Explanation:</h2>
Carbon is essential part of living organisms. Scientist use carbon isotopes for dating purposes but the problem with carbon isotopes is also limited as Carbon dating only works for objects that are younger than about 50,000 years, and most rocks of interest are older than that
The answer is all of the above
