Unit 13 Review

Bioindicators (biological indicators) are used to measure the quality of water. What is a biological indicator?

• any living creature

• producers in aquatic environments

• An organism sensitive to its environment that can indicate the quality of water.

• algae

A body of water showed a high turbidity level, high levels of nitrates and phosphates, a pH of 7.5, and low dissolved oxygen levels. Would this body of water be considered healthy?

• Yes

• No

How could the use of fertilizers near the stream impact the health of a stream?

• Nitrates and phosphates from fertilizer lead to algal blooms

• Fertilizers are consumed by fish

• Fertilizers do not impact water quality

• Fertilizers use on land improves water quality

What is the healthiest combination listed?

• low pH, high nitrates, neutral temperature
• low temperature, neutral pH and low nitrates
• as many nitrates as possible, low temp and low pH
• high temp, high nitrates and high pH

How do low Dissolved Oxygen levels ( 3 or below) affect organisms?

• Organisms may die or have to leave if levels get too low

• Organisms go through more cellular respiration

• Organisms eat more

A substance with a pH of 8.2 is a __________ base (alkali) while a substance with a pH of 2 is a __________ acid.

• weak, weak

• weak, strong

• strong, strong

• strong, weak

Which of the following can directly increase water turbidity?

• Decreased temperature

• Increased pH.

• Increased soil erosion

• Increased DO.

The rapid growth of algae, called an algal bloom, can lead to the formation of dead zones that cannot sustain aquatic life. This is mainly because the algal bloom lowers the amount of –

• chemical pollutants

• dissolved oxygen

• freshwater runoff

For what types of water does the Clean Water Act relate to?

• surface waters
• ocean waters

Water from rain or snow that flows over land before ending up in a body of water.

• surface runoff

• filtration

• storm drain

• sediment filter