Which of the following characteristics is true for bacterioplankton?

• A. They are free-living bacteria found in aquatic environments.
• B. They are large, multicellular organisms.
• C. They are exclusively found in soil habitats.
• D. They are obligate intracellular parasites.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the term 'bacterioplankton' by breaking it down: 'bacterio-' refers to bacteria, and '-plankton' refers to organisms that drift in water bodies.
2. Step 2: Recall that planktonic organisms are typically free-living and suspended in aquatic environments such as oceans, lakes, and rivers.
3. Step 3: Recognize that bacterioplankton are microscopic, unicellular bacteria, not large or multicellular organisms.
4. Step 4: Note that bacterioplankton are not restricted to soil habitats; instead, they are primarily found in water environments.
5. Step 5: Understand that bacterioplankton are generally free-living and not obligate intracellular parasites, which require a host cell to survive.