[Campbell Biology P.1229] Which of the following correctly describes a difference between hea... | Practice Question

Which of the following correctly describes a difference between headwater streams and downstream river sections?

  • A: Headwater streams are generally warmer and more turbid than downstream river sections.
  • B: The salt and nutrient content decreases from headwaters to the mouth of a river.
  • C: Headwater stream channels are generally wide and meandering, while downstream stretches are narrow with rocky bottoms.
  • D: Headwaters are generally rich in oxygen, whereas downstream water may have substantial oxygen unless organic enrichment occurs.

Explanation

According to the 'Chemical Environment' section under 'Streams and Rivers', headwaters are generally rich in oxygen, and downstream water may also contain substantial oxygen, except where there has been organic enrichment. The other options describe the opposite or incorrect characteristics.