Microbial Diversity

Total water filtered = 10 L Convert to ml: The filter collects all organisms from these 10000 ml, and produces 64 CFU on the agar plate. Thus the concentration is: Therefore, the average concentration of coliform organisms in the sample is Final Answer: (C)

A plasmid-free bacterial cell contains a single circular chromosome, which means the number of DNA molecules is exactly:
DNA = 1.
Protein molecules are the most abundant macromolecules in any bacterial cell.
Given that there are 2500 different protein types, each with at least one copy, the total protein count must satisfy:
Protein .
RNA constitutes 21% of bacterial cell dry weight and includes:
• mRNA (many copies of each gene transcript),
• tRNA (high copy number),
• rRNA (thousands of copies).
Therefore, the total RNA molecule count is much larger than 2500.
Thus, RNA Protein .
Now examine each option:
(A) DNA = RNA = Protein
This is incorrect because DNA = 1, while RNA and proteins are far more numerous. Hence (A) is NOT correct.
(B) DNA = RNA = 1; Protein
This is incorrect because RNA molecule count is never equal to 1; it is extremely large. Thus (B) is NOT correct.
(C) DNA = 1; RNA = Protein
RNA count is far greater than protein count, so this is also incorrect. Thus (C) is NOT correct.
(D) DNA = 1; RNA>Protein
This is the only correct statement. RNA is indeed larger in number than proteins, and both exceed 2500 molecules.
Therefore, the statements that are NOT correct are (A), (B), and (C).
Final Answer: (A), (B), (C)

Step 1: Analyze statement (i).
Aerobic heterotrophic bacteria obtain both carbon and energy from organic matter (since they cannot fix CO ). Thus, statement (i) is correct.
Step 2: Analyze statement (ii).
Heterotrophs cannot use CO as their carbon source. Only autotrophs fix CO . Thus, statement (ii) is incorrect.
Step 3: Analyze statement (iii).
Aerobic autotrophic bacteria (like nitrifying bacteria) fix CO as their carbon source and use reduced substances (like NH , NO ) as their energy source. Thus, statement (iii) is correct.
Step 4: Analyze statement (iv).
Autotrophs do not rely on organic matter for energy; instead, they use inorganic sources or light. Thus, statement (iv) is incorrect. Hence, the correct choice is: (i) and (iii) are correct. Final Answer:

Step 1: Understanding Anabolism.
Anabolism is indeed the process of utilizing carbon (and other elements) to build complex molecules such as proteins, lipids, and nucleic acids, contributing to cell synthesis. So, statement (i) is correct.

Step 2: Understanding Catabolism.
Catabolism refers to the breakdown of larger molecules into simpler ones, releasing energy. However, during catabolic reactions, ATP is typically broken down into ADP, but the energy release process isn't solely associated with the conversion of ATP to ADP. ATP is utilized to drive the cellular processes, while the release of energy during catabolism is often linked to the breakdown of molecules (like glucose) rather than the simple conversion of ATP to ADP.

Since the conversion of ATP to ADP doesn't fully describe the energy release mechanism in catabolism, statement (ii) is incorrect.

Thus, the correct option is (C) (i) is correct and (ii) is incorrect.