Hydrosphere

How much of Earth's water is unavailable for humans to consume due to its high salinity? 

• 3%
• 23%
• 77%
• 97%

Why must humans clean water before using it? 

• Humans are unable to digest untreated river water
• River water is free of any contaminant or pollutants
• Untreated river water is brown and humans prefer clear water
• Clear water may contain contaminants that could harm humans
  

How does the amount of water circulating in the water cycle change?

• The amount of water remains constant
• The amount of water increases each time it rains
• he amount of water decreases and then increases each day
• The amount of water decreases every time evaporation occurs

How is freshwater treatment different from wastewater treatment?

• Freshwater contains oils and vitamins needed for health

• wastewater is not treated after use to protect the environment

• Wastewater removes pollution to make potable water

• Wastewater is treated after use to protect the environment

Which statement best describes how estuaries are positive environment for animals and plants

• They flood regularly destroying organisms' habitat

• They provide a safe hatchery full of nutrients and food

• They dry up each summer stranding organisms in shallow water

• hold high numbers of predators to feed off young organisms

How is the intertidal zone different from the open ocean environment?

• Conditions in the intertidal zone remain constant
• The intertidal zone's conditions constantly change
  
• The open ocean is the shallowest zone in the ocean
• the conditions in the open ocean change continually

Why is nitrogen gas important to the health of the ocean and its organisms?

• It is needed to make amino acids, proteins, and DNA
  
• It is the main gas needed for photosynthesis
• is needed to produce energy during cellular respiration
• Hard-shelled organism need it to make their shells.

How does mining on the ocean floor negatively affect the surrounding ecosystems?

• High turbidity clog the gills of ocean organisms
  
• Heavy metals in the food chain causing fish to weigh more.
• Increase in suspended solids cover fish make them invisible
• Suspended solids in water blind organisms

How does warmer temperature affect plants living in the ecosystem? 

• holds less solids, allowing pants to grow year round
• Holds less gases, making plants to use gas stores in cells
• Holds more oxygen, letting plants conduct photosynthesis
• Holds more solids, blocks sunlight, and stops photosynthesis
  

How can a change in the pH of water affect the ecosystem

• Higher pH levels suffocates fish and causes them to die
• Lower pH levels creates a healthier environment for fish
• Change in pH affect which biological &chemical process occur
  
• pH levels changes the temperature of water