Question

Daphnia is a:

• A. Planktonic form
• B. Neuston
• C. Nekton
• D. Periphyton

Hint:

Daphnia is an important freshwater zooplankton commonly called the water flea.

Answer 1

The Correct Option is A

Concept:
Daphnia is commonly called the water flea. It is a small freshwater crustacean. 

Step 1: Understand the ecological categories.
\[ \begin{aligned} \text{Plankton} &\rightarrow \text{Drifting organisms} \\ \text{Nekton} &\rightarrow \text{Active swimmers} \\ \text{Periphyton} &\rightarrow \text{Attached organisms} \\ \text{Neuston} &\rightarrow \text{Surface dwellers} \end{aligned} \] 

Step 2: Classify Daphnia.
Daphnia drifts with water currents.
Therefore it belongs to zooplankton. \[ \text{Daphnia} \rightarrow \text{Planktonic organism} \] 

Step 3: Select the correct option.
Hence, \[ \boxed{\text{Option (A)}} \] is correct.