Which statement about aquatic life support systems is true?

Which statement about aquatic life support systems is true?

• A. They are always a simple container with no additional components.
• B. They cannot include biological filtration.
• C. They are limited to closed loop systems.
• D. They may be a simple container (closed), a flow-through system, or a complex recirculating system with filtration.

Answer: (D)

Aquatic life support systems come in a range of configurations, all aimed at keeping water quality, oxygen levels, temperature, and waste under control for the organisms being kept. They can be a simple closed container with basic aeration, a flow-through setup that continually introduces fresh water, or a complex recirculating system that uses filtration to clean and reuse water. This breadth is why the statement describing the possibilities—simple closed, flow-through, or a complex recirculating system with filtration—is true. Why the other ideas don’t fit: a bare container without components wouldn’t reliably maintain water quality; biological filtration is a common and important part of many systems, so excluding it isn’t accurate; and limiting systems to closed loops ignores the many flow-through designs used in various settings.

Aquatic life support systems come in a range of configurations, all aimed at keeping water quality, oxygen levels, temperature, and waste under control for the organisms being kept. They can be a simple closed container with basic aeration, a flow-through setup that continually introduces fresh water, or a complex recirculating system that uses filtration to clean and reuse water. This breadth is why the statement describing the possibilities—simple closed, flow-through, or a complex recirculating system with filtration—is true.

Why the other ideas don’t fit: a bare container without components wouldn’t reliably maintain water quality; biological filtration is a common and important part of many systems, so excluding it isn’t accurate; and limiting systems to closed loops ignores the many flow-through designs used in various settings.