Question

Which of the following are Cyanobacteria?
• [(A)] Nucleopolyhedrovirus
• [(B)] Anabaena
• [(C)] Nostoc
• [(D)] Oscillatoria Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. A, B, C and D
• D. B, C and D only

Hint:

Examples of cyanobacteria: \[ \mathrm{Anabaena} \] \[ \mathrm{Nostoc} \] \[ \mathrm{Oscillatoria} \]

Answer 1

The Correct Option is D

Step 1: Understand Cyanobacteria.
Cyanobacteria are: \[ \mathrm{Photosynthetic\ Prokaryotes} \] commonly called: \[ \mathrm{Blue\text{-}Green\ Algae} \]

Step 2: Analyze each organism.
Nucleopolyhedrovirus It is a virus and not a cyanobacterium. \[ \Rightarrow \mathrm{Incorrect} \] Anabaena A nitrogen-fixing cyanobacterium. \[ \Rightarrow \mathrm{Correct} \] Nostoc A filamentous cyanobacterium. \[ \Rightarrow \mathrm{Correct} \] Oscillatoria A common cyanobacterium found in aquatic habitats. \[ \Rightarrow \mathrm{Correct} \]

Step 3: Identify the correct combination.
Correct organisms are: \[ B,\ C,\ \text{and}\ D \] Hence, the correct answer is: \[ \boxed{\mathrm{(D)}} \]