6.3 Aquatic Ecosystems Pt. 1

What percentage of Earth's surface is covered in water?

• 50%

• 75%

• 25%

• 90%

Aquatic systems are characterized by factors such as water salinity, depth, and water _______ or standing.

What are some criteria used to classify aquatic ecosystems?

• Temperature, pH level, and biodiversity

• Salinity, depth, and water flow

• Soil type, vegetation, and animal species

• Altitude, precipitation, and humidity

_____________ enable organisms to maintain careful water and salt balance with their surroundings in aquatic ecosystems.

What does salinity measure in water?

• Amount of salts dissolved

• Temperature

• pH level

• Oxygen content

The presence of sunlight causes warmer temperatures in upper layers of aquatic ecosystems. True or False?

What is the uppermost layer of an aquatic ecosystem where there is enough sunlight for photosynthesis called?

• Abyssal zone

• Photic zone

• Benthic zone

• Pelagic zone

What is the primary factor determining light availability in aquatic ecosystems?

• Water temperature

• Water depth

• Water salinity

• Water flow

How do most aquatic consumers obtain the oxygen they need?

• From water taken in through gills

• From air taken in through lungs

• From food they consume

• From sunlight

Aquatic ecosystems are sometimes divided into how many categories?