Practise MYP Biology questions on 6.4 Ecosystem Cycles and review the explanations to check your understanding.
Use these questions for topic practice and to find ideas you want to revisit in your notes or lessons.
True or False: The primary cause of oxygen depletion (hypoxia) in a dead zone is the rapid respiration of decomposers breaking down massive amounts of dead algae.
Which statement best describes the difference between how energy and matter behave in an ecosystem?
What is the primary biological reason for the development of 'dead zones' in aquatic environments after algal blooms?
Why is it essential for matter to be recycled in a closed system like Earth?
Phosphorus is a crucial component of __________, the molecules that form the bilayer of cell membranes.
True
False
Both energy and matter cycle continuously through the environment
Energy cycles through organisms while matter flows in one direction
Matter flows in one direction and is lost to space while energy is recycled
Energy flows in one direction and is lost as heat, while matter cycles
The algae use up all the dissolved carbon dioxide
Fish use up the oxygen trying to eat the excess algae
Decomposers use up dissolved oxygen while breaking down dead algae
The algae produce toxic levels of nitrogen gas
Because the planet receives almost no new matter from external sources
Because matter is eventually converted into heat and lost to space
Because decomposers destroy elements during the breakdown of waste
Because Earth receives a constant influx of new matter from sunlight
phospholipids
polysaccharides
triglycerides
amino acids
