Question

which best describes the difference between protists that have cilia and those that have flagella?
those that have cilia are animal - like protists, and those that have flagella are plant - like protists.
those that have flagella are animal - like protists, and those that have cilia are plant - like protists.
those with cilia move using hair - like extensions, and those with flagella move using a single whip - like extension.
those that have cilia are heterotrophs, and those that have flagella are autotrophs.

Explanation:

To solve this, we analyze each option:

• Option 1: Cilia/flagella presence doesn't strictly define animal/plant - like protists. Many with flagella are animal - like (e.g., trypanosomes), so this is wrong.
• Option 2: Similar to option 1, cilia - bearing protists can be animal - like (e.g., paramecium), and this misclassifies, so wrong.
• Option 3: Cilia are hair - like (many short) extensions for movement, flagella are usually a single (or a few) whip - like extension for movement. This correctly describes the structural and functional difference in movement.
• Option 4: Both cilia - and flagella - bearing protists can be heterotrophs or autotrophs (e.g., euglena with flagella is mixotrophic), so this is wrong.

Answer:

Those with cilia move using hair - like extensions, and those with flagella move using a single whip - like extension.