Download ES CH 4 Test Review

ES CH 4 TEST ITEMS
1. Ecology is the study of how organisms interact with each other and with their
environments.
2. A species is a group of individuals that interbreed and produce fertile offspring.
3. Members of a species that live in the same area at the same time make up a
population.
4. All of the populations in a particular area make up a community.
5. Community ecology is the study of interactions among species.
6. An ecosystem includes all of the living things and their physical environments within a
particular area.
7. The biosphere includes all parts of Earth that host life, with all of its organisms and
environments.
8. Parts of an ecosystem that are living or used to be living are called biotic factors.
9. Parts of an ecosystem that have never been living are abiotic factors.
10. The specific environment in which an organism lives is its habitat.
11. A resource is anything an organism needs
12. Population size describes the number of individual organisms present in a given
population at a given time.
13. Population density describes the number of individuals within a population per unit
area.
14. Population distribution (sometimes called population dispersion) describes how
organisms are arranged within an area.
15. Random distribution: individual organisms are arranged in no particular pattern.
16. Uniform distribution: individual organisms are evenly spaced throughout an area.
17. Clumped distribution: individual organisms arrange themselves according to the
availability of the resources they need to survive.
18. Age structure, or age distribution, describes the relative numbers of organisms of
each age within a population.
19. Age pyramids, or age structure diagrams, are visual tools scientists use to show the
age structure of populations.
20. A population’s sex ratio is its proportion of males to females.
21. To show how the likelihood of death varies with age, population ecologists use
graphs called survivorship curves.
22. Immigration is the arrival of individuals from outside a given area.
23. Emigration is the departure of individuals from a given area.
24. Migration is a seasonal movement into and out of an area.
25. When a population increases by a fixed percentage each year, it is said to undergo
exponential growth.
26. Limiting factors are characteristics of the environment that limit population growth.
27. Carrying capacity is the largest population size a given environment can sustainably
support.
28. Logistic growth describes how a population’s initial exponential increase is slowed
and finally stopped by limiting factors.
29. Density dependent factors are influenced by changes with population density.
Density independent factors are NOT.
30. Biotic potential: maximum ability to produce offspring in ideal conditions.