Download Ecology Review Sheet

Name: __________________________
Ecology Review Sheet
Use questions & answers to prepare for your upcoming unit test.
1. Put the following in order from smallest to largest: biome, community, biosphere, ecosystem, population
a. Give an example of each term OR sketch a picture for each.
Population (group of lions), community (lions and their prey – gazelles), ecosystem (includes all biotic &
abiotic – like weather), biome (location defined by climate, plants), biosphere (region of earth where life can
survive)
Rock
Fire
Flower
Rain
2. In the box to the right, underline the abiotic factors. Are the rest biotic? Explain.
Wind
Human
The rest of the factors are biotic, because they are living
Butterfly
Jellyfish
Dog
Deer
3. What is the relationship between biodiversity and the stability in an ecosystem?
The more biodiversity, the more stable and resilient ecosystems are to changes.
4. Give 2 examples of biotic and 2 examples of abiotic factors that could impact (change) ecosystem stability.
Biotic: competition, predation, disease
Abiotic: Temperature, levels of CO2 and O2, water availability
5. Explain how environmental changes such as algal bloom and deforestation could impact ecosystem stability.
Algal bloom: affects oxygen levels, which kills fish, disrupting the entire food web
Deforestation: loss of habitat disrupts the food web, can lead to succession to take place
6. Define biological magnification. Give a good example. It is the buildup of toxins in the upper trophic levels of a
food chain. DDT (chemical pesticide that reduced the bald eagle population)
7. How do ecosystems heal themselves after an environmental change? Succession
8. What is ecological succession?
9. Primary succession starts with (barren rock; soil). Secondary succession starts with a (barren rock; soil).
10. Give examples of pioneer organisms that colonize barren rock after a disturbance such as a volcano eruption.
Lichens and mosses
11. What events (disturbances) cause primary and secondary successions?
Primary: volcano eruption (new rock formed without existing soil)
Secondary: deforestation, a forest fire (existing soil present)
12. How could forest fire change populations in the ecosystem? Burn the mature plants, leaving only smaller plants.
Allows new plants to move in.
How could forest fire change species diversity in the ecosystem? It drastically decreases diversity- the mature
plants (trees, shrubs, etc) are replaced with only highly adapted plants (grasses)
13. What is a climax community? Mature, self-sustaining, diverse  stable succession (ex. Mature forest with pines
and oaks)
14. Draw a food chain that includes 4 organisms.
a. Label the producer, primary consumer, secondary consumer, and tertiary consumer
b. Label each link as an autotroph, omnivore, herbivore or carnivore
Grass (producer)  grass hopper (primary)  bird (secondary)  snake (tertiary)
AUTOTROPH
HERBIVORE
CARNIVORE
CARNIVORE
15. Where is the most efficient place for you to eat in a food chain? The algae (would get most of the energy
provided by the sun – 10%)
16. What do the arrows indicate
in the food chain in
the question #15? Flow of
energy
17. In an ecosystem matter (cycles; flow) and energy (cycles; flow).
18. How much energy is transferred between trophic levels? 10%
What happens to the rest of energy? Lost as heat
19. Where is there the most amount of energy available in a food chain or food web? Producer level (bottom)
20. Define niche. An organisms role (“job”) in the environment
21. What is habitat? The specific environment an organism lives in (ex: desert habitat)
22. Of the following, which does not cycle through the environment? Nitrogen, Oxygen, Carbon, Water and Energy
23. What is symbiosis? Living together – at least one organism benefits
24. What is a competition? Competition occurs when two organisms fight for the same resources. Such as two
different species of animals competing for the same food.
25. Give an example of predator-prey relationship. Lion and zebra.
26. If the population of prey decreases then the predator population will also decrease. Why? b/c of lack of food.
27. What is the difference between predation and parasitism?
Predator kills the prey for food. Parasites need the host for food, shelter, etc. – weakens the host, but does not
intentionally kill it.
28. Label each of the examples below as: mutualism, parasitism or commensalism
a. bees pollinate flowers and eat the nectar mutualism
b. ticks suck the blood of a dog parasitism
c. caterpillars eat the leaves of trees parasitism
d. a remora swims with a shark and eats food scraps commensalism
MAKE UP your own: ____________________________________________________
29. Give examples of decomposers. Fungi and bacteria What is their job? Chemically breakdown organic matter aid in nutrient recycling.
30. Organisms, populations, and communities respond to external stimuli - factors (something that cause a
response) There are biotic and abiotic factors. Why do some animals migrate south in the winter? Avoid cold.
What external factor do these animals respond to? Low temperatures.
Why do they respond? Maintain homeostasis
31. What role do microorganisms such as E-coli bacteria play in keeping our large intestine healthy? Bacteria help
us get nutrients out of some food that we would not be able to digest all on our own. They produce vitamin K –
aids in blood clotting.
What role do microorganisms such as pathogenic bacteria and fungi play in disrupting the health of organisms?
Give an example. Some bacteria can cause strep throat. Fungi infect skin and nails.
32. Draw a graph that represents exponential growth
a. Does this happen in nature? no
b. Are there limiting factors present in the environment? yes
33. Draw a graph that represents logistic growth
a. Does this happen in nature? yes
b. Label the feature that represents the carrying capacity.
c. Are there limiting factors present in the environment? yes
d. Label the portion of the graph that shows exponential growth first section, in bracket
34. What is carrying capacity? It is the maximum population size that environment can support – size of population
at which a population can no longer grow due to lack of supporting resources.
35. What variations and adaptation would you expect to see in plants in the tundra?
Plants are small – roots cannot penetrate the permafrost. Some plants are covered with hair – help keep them
warm.
36. What variations and adaptations would you expect to see in animals in the desert?
Many animals migrate during the dry season to search for water. Animals borrow for protection from the heat
and lack of water. Active at night (nocturnal) to avoid heat.
37. In which chemical cycle does photosynthesis play a role, carbon or nitrogen? Carbon
38. What could happen if a carbon cycle is disrupted by burning fossil fuels? Burning fossil fuels, like coal, oil, and
natural gas, releases carbon dioxide into the upper atmosphere. The carbon dioxide gas is a greenhouse gas
that acts like a blanket, trapping heat in our atmosphere.
39. What is nitrogen fixation? When nitrogen-fixing bacteria convert unusable nitrogen molecules (like ammonia)
into useable nitrogen (like nitrates) for plants
40. What could happen if the nitrogen cycle is disrupted? All organisms need to build proteins. Disrupting N-cycle
will affect plants and their ability to make proteins  will affect heterotrophs.