Download Population and Ecosystem

Population and Ecosystem Study Guide
Biology
Name: ___________________________
1. Population – a group of similar organisms in a given area
2. Reasons why populations increase
Birth rate increasing, death rate decreasing, higher immigration
3. Immigration - organisms coming into an area
4. Emigration – organisms leaving an area
5. Approximate world population – 7 billion
6. Limiting factors – help keep a population from growing (water,
space, food)
7. Limiting factors: density dependent – affected by the number of
individuals in a given area. Ex. Predation, competition,
parasitism, disease
8. Limiting factors: density independent – limit a population’s growth
regardless of the density. Ex. Weather, disasters, human activities
9. Community – all the living things in an area
10.Ecological Niche – “job” or “role” within their habitat. Includes
food, abiotic conditions, behavior
11.abiotic – nonliving things in an ecosystem ex. Weather, soil,
moisture
12. biotic – living things in an ecosystem ex. Plants, bacteria, fungus,
animals
13. Ecosystem - biotic and abiotic factors interacting in an area
14. Place the following terms in order of organization from smallest to
largest: population, biome, community, organism, ecosystem
Organism, population, community, ecosystem, biome
15. Habitat – place an organism lives
16. Keystone species – a species that has an unusually large affect on
its ecosystem
17. Producer – organism that makes its own food ex. Plant, algae. Most
of the organisms in food web are producers
18. Primary Consumer – organism that eats a producer
19. Secondary consumer – eats other animals (primary consumers)
20. Tertiary consumer – a third level consumer
21. Consumer- organism that consumes other living things ex. animals
22.Decomposer – recycles nutrients back into the community ex.
Bacteria, fungus
23. Food chain – shows pathway of energy through a community
24.Food web – several food chains connected together
25.What happens to energy as it moves through a food chain? Energy decreases
(lost as heat). Producers have the most energy
26. Primary source of energy - sun
27. Mutualism – relationship where both organisms benefit
28. Commensalism – one organism benefits, the other is unaffected
29. Parasitism – one organism benefits, the other is harmed
30. Predator – animal that eats other animals
31. Prey – animal that is hunted by predator
32. Predator/prey relationship – prey population decreases as predator
increases