1. Ecology Study Guide Answers

2. Define:
Ecology- the study of the interaction of living organisms with each other and their environment
Community- a group of organisms of different species living together in a particular place
Habitat- specific location in which a species lives
Biomass- the organic material in an ecosystem
Density-independent factor- factors that do not depend on how dense the population

3. f. Density-dependent factor- factors that do depend on how dense the population is
g. Parasitism- one organism benefits, the other is harmed
h. Commensalism- one organism benefits, the other is not affected
Mutualism- both organisms benefit
j. Succession- transformation over time; regular progression of species replacement in an environment
k. biome- major ecosystems that occur over wide areas of land

4. What does an ecosystem consist of?
A community of organisms, energy, soil, water, weather
2. What does an organisms’ niche consist of?
What it eats, where it eats, when it eats, etc.
3. What happens to the nitrogen when an organism dies?
It is released by the action of the decomposers
4. What happens to the energy when going from one trophic level to the next?
The amount of usable energy decreases.

5. 5. What are the components of the water cycle
5. What are the components of the water cycle? Precipitation, evaporation 6. How is nitrogen used and cycled? Conversion of atmospheric nitrogen into usable compounds by bacteria, nitrogen fixation, conversion of nitrogen from decaying organisms into ammonia 7. How do humans affect the carbon cycle? Burning fossil fuels, destroying vegetation, clearing forests 8. What do demographic studies of populations take into consideration? Population size, population density, population dispersion

6. 9. A population of organisms grows under which conditions
9. A population of organisms grows under which conditions? When the birth rate exceeds the death rate 10. As a population reaches its carrying capacity, what will there be competition for? Food, shelter, mates 11. What is an example of a density-independent factor? Severe weather 12. Where is the human population growth most rapid? Developing countries Ex) Mexico

7. 13. Give an example of the following:
parasitism- tick feeding on a human
Mutualism- flower and bee
Commensalism- barnacle attached to whale
14. Describe an ecosystem closest to the equator.
Have higher species richness than an ecosystem north or south, long growing season, warm temperature
15. What is the difference between primary and secondary succession?
P- ecosystem develops from scratch; S- ecosystem is rebuilt from what was already there

8. 16. What type of producer would primary succession contain in the early stages?
Rock lichens
17. Describe the following biomes:
taiga- evergreen trees that are adapted to long wingers, short summers, and nutrient-poor soil
Tropical forest- heavy rain, warm, rich in species
Temperate forest- 4 seasons, deer, racoons
Tundra-cold, low biodiversity, short season of growth,

9. e. savanna- large herds of grazing animals, grasslands f
e. savanna- large herds of grazing animals, grasslands f. desert- few rainfall, sandy soil g. Omit 18. Give an example of a biotic and abiotic factor. Biotic- animal, tree; Abiotic- light, weather 19. All living things contain which element? Carbon 20. What is first formed from a pioneer species? soil

10. 21. Name all of the components of the biosphere
21. Name all of the components of the biosphere. Ocean bottoms, atmosphere, land masses 22. What is another name for an autotroph? Producer Add: 23. what is the difference between interspecific and intraspecific competition? Interspecific- between different species Intraspecific- between the same species