Download Chapter 8 Word Study - Understanding Populations

Your Name ____________________________________Period ______ Date __________
Environmental Science Chapter 8 Word Study - Understanding Populations
Directions: Study the following words by reading and rereading them each evening so you will be
prepared for the word study test each week. You may use one index card to write as many words
and definitions on as possible to use for the test. The card must written in ink, be in your
handwriting, and have your name, your class period, and the chapter recorded in the top, right
corner with no obvious erasures or mark outs. ALL WORDS MUST BE NUMBERED. If all the
criteria are met, you may use your index card during the test. It will then be stapled to your test.
1.)
population - a group of organisms of the same species that live in a specific
geographical area and interbreed
2.)
density - the number of individuals of the same species that live in a given unit
of area
3.)
dispersion - in ecology, the pattern of distribution of organisms in a population
4.)
growth rate - an expression of the increase in the size of an organism or
population over a given period of time
5.)
reproductive potential - the maximum number of offspring that a given
organism can produce
6.)
exponential growth - logarithmic growth, or growth in which numbers
increase by a certain factor in each successive time period - populations
that grow faster and faster
7.)
carrying capacity - the largest population that an environment can support at
a given time or the number of individuals that the resources of an
environment can normally and persistently support
8.)
niche - the unique position occupied by a species, both in terms of its physical
use of its habitat and its function within an ecological community
9.)
competition - a group of various species that live in the same habitat and
interact with each other
10.) predation - an interaction between two organisms in which one organism, the
predator, kills and feeds on the other organism
11.) parasitism - a relationship between two species in which one species, the
parasite, benefits from the other species, the host, which is harmed by
the interaction - examples: fleas and ticks that feed on the blood of
mammals
12.) mutualism - a relationship between two species in which both species benefit
- example: humans produce carbon dioxide as a waste product and
plants use carbon dioxide in photosynthesis to produce oxygen that
humans need
13.) commensalism - a relationship between two organisms in which one organism
benefits and the other is unaffected - example eye mites, demodicids,
that live in the roots or hair follicles of human eyelashes
14.) symbiosis - a relationship in which two different organisms live in close
association with each other - example: clownfish and sea anemone, the
clownfish receives protection from the stinging tentacles of the sea
anemone and the sea anemone gets leftover pieces of food from the
clownfish
15.) density dependent deaths - deaths that occur more quickly in a crowded
population than in a sparse population which happens when individuals
live crowded together/Example: diseases that spread quickly through
crowded conditions are deaths in this way
16.) density independent deaths - deaths that occur when a portion of a population
dies irregardless of the population's density. Severe weather and natural
disasters are often methods that cause deaths in nature.