Living Things
The 7 characteristics of living things can be remembered by the acronym MRS GREN. What do M and R stand for?
Movement and Respiration
This abiotic factor is the most important in any ecosystem because it provides the initial energy for all plants.
Sunlight
What percentage of energy is typically passed from one trophic level to the next?
10%
Name the green pigment found in chloroplasts that captures light energy.
Chlorophyll
Name two of the four resources that plants and animals most commonly compete over.
Energy (food/sun), Nutrients, Water, or Space.
Sunlight, rocks, and humidity are examples of this type of factor (non-living).
Abiotic factors
Organisms that are "self-feeders" and produce their own food using light are called...
Autotrophs (or Producers)
A food chain shows a one-way path of energy. What model shows multiple interconnected paths of energy?
A Food Web
What are the two "ingredients" (reactants) a plant must take in to perform photosynthesis?
Water (H2O) and Carbon Dioxide (CO2)
What is the name for competition between two different species for the same limited resource?
Interspecific Competition
Living things depend on each other and non-living things for survival. This is called...
Interdependence
Secondary consumers occupy Level 3 of the pyramid. What do they typically eat?
Primary Consumers (Herbivores)
According to the 10% Rule, if the primary consumers have 500 units of energy, how much energy will the secondary consumers receive?
50 units
Photosynthesis produces Glucose (food). What is the other product, often considered a waste product by the plant?
Oxygen
What is the name for competition between members of the same species?
Intraspecific Competition
Put these in order from smallest to biggest: Population, Ecosystem, Individual, Community.
Individual -> Population -> Community -> Ecosystem
Explain the role of decomposers (like fungi and bacteria) in a trophic system.
They break down dead matter and return nutrients to the soil for producers to use.
Food webs are often called a "safety net" for ecosystems. Why is a web more stable than a chain?
Because if one food source disappears, predators have other prey options to survive.
Explain how gases enter/leave the plant, and how water travels from the roots to the leaves.
Gases through Stomata (leaf holes); Water through Xylem (vein-like structures).
Define a "Trophic Cascade."
A domino effect where one change (like removing a predator) triggers many other changes down the food chain.
The largest level of biological organization, containing all living things on Earth.
The Biosphere
Why are tertiary consumers (apex predators) always the smallest population in an ecosystem?- Your answer must talk about energy
Because only 10% of energy is passed up each level, leaving very little energy to support many top predators.
On Wolf Island, what was the specific "chain reaction" that occurred after the wolves were removed?
Deer overpopulated -> Vegetation was over-eaten -> Deer eventually starved/died out.
How is the glucose produced in photosynthesis used by the plant cell later on?
It is used in Cellular Respiration to produce ATP (energy).
Describe how the removal of wolves could eventually change the physical shape of a river.
No wolves -> more deer -> less plants -> roots die -> soil erodes -> river banks collapse/change shape.