"Variation in Protein Structure Is the Basis of Biological Diversity" Explain this statement ?

Bacteria are by far the most numerous organisms on earth.  Some estimates indicate that the total biomass of bacteria is  larger than that of all plants and animals, despite their tiny size.  However, biologists' knowledge of bacteria is very uneven.  In some ways, biologists know more about certain bacteria than we do about most animals, including humans.  In other ways, biologists still know very little about bacteria and the Bacteria Kingdom.  For example, there might be about a million species of bacteria, or there could be billions of different species.   Think about benefits and complications related to the biological study and knowledge of bacteria.  What are some ways in which bacteria are very well-known and/or easy to study?  What are some ways in which bacteria are very poorly-known and/or difficult to study (other than the total number of species).  Discuss how this relates to technology, other developments in biological research, and/or characteristics of the bacteria…

If a species' genome is 20% cytosine, how much is adenine?   Question 1 options: If a species' genome is 20% cytosine, how much is adenine?   20%   30%   10%   50%

Pls help ASAP