Understanding SAG Curves and Environmental Impact 2

What does a SAG curve graphically represent?

• The migration patterns of aquatic life

• The seasonal changes in river water levels

• The temperature variations in a marine environment

• The effect of organic pollution on a river's dissolved oxygen and BOD

What is meant by 'organic pollution'?

• Chemical waste from industrial processes

• Plastic and synthetic waste in water bodies

• Air pollution from vehicles

• Pollution that originated from living organisms

What does BOD stand for?

• Biological Oxygen Demand

• Basic Oxygen Distribution

• Biodegradable Organic Dust

• Bacterial Organism Decay

Which zone is characterized by the lowest level of dissolved oxygen?

• Septic zone

• Decomposition zone

• Recovery zone

• Clear zone

What is the primary role of decomposers in the context of organic pollution?

• They filter pollutants out of the water

• They increase the level of dissolved oxygen

• They produce organic pollution

• They break down organic matter using oxygen

What is the 'sag point' in a SAG curve?

• The point of lowest dissolved oxygen in the water

• The highest point of BOD in the water

• The starting point of pollution dumping

• The recovery point where oxygen levels begin to rise

What type of life is most likely to be found in the septic zone of a polluted river?

• Birds and insects

• Fish and marine mammals

• Bacteria and other decomposers

• Aquatic plants and algae

How does cultural eutrophication relate to the effects shown by a SAG curve?

• Both result in an increase in water clarity

• Both are unaffected by human activities

• Both are primarily caused by thermal pollution

• Both involve depletion of dissolved oxygen due to organic matter decomposition