envs chapter 1-3 Flashcards
The eutrophication that has taken place in the Gulf of Mexico and other locations appears to be due to ________.
excess nutrients from fertilizers
The rate at which biomass becomes available to consumers is termed ________.
net primary productivity
Humans have dramatically altered the rate of nitrogen fixation into forms usable by plants ________.
as we produce synthetic fertilizers and apply them to crops, lawns, and parks
Nitrogen fixation is a process that makes nitrogen available to plants and is carried out by ________.
mutualistic and free-living microbes
The origin of all nitrogen in biological tissues is ________.
atmospheric N2 gas
During photosynthesis within plants, ________.
there is net consumption of water and carbon dioxide
The origin of all phosphorus in biological tissues is ________.
phosphorus weathered from rock
The largest pools of carbon in the carbon cycle are ________.
sedimentary rock and fossil fuels
In an eutrophic aquatic ecosystem dissolved oxygen ________ and dissolved macronutrients ________.
decreases/increase
Why is the hydrologic (water) cycle so important in ecosystems and for nutrient cycles on Earth in general?
Besides providing people, animals and plants with water, it also moves things like nutrients, pathogens and sediment in and out of aquatic ecosystems.
Eutrophication is a complex process in ecosystems. Describe 5 of the main steps in this process, in order
A farmer/person adds fertilizer to their land or fields.
It rains and makes the crops/grass grow and the fertilizer soaks into the ground water.
The fertilizer makes the algae grow in lakes and ponds. This is called a algal bloom.
The algae blocks the sun causing plants to die. then they cannot give off oxygen for the fish to breathe.
Bacteria grows and uses up all the oxygen. Water with no oxygen is called anoxic.
Which of the following represents an example of cellular respiration?
glucose + oxygen –> water + carbon dioxide + energy
