Lab Exam 1

Question 1

statistical population

Answer 1

the entire set of data of interest (i.e., the weights of all of the mice)

Question 2

the entire set of data of interest (i.e., the weights of all of the mice)

Answer 2

statistical population

Question 3

statistical sample

Answer 3

the measured portion, or subset, of the population

Question 4

the measured portion, or subset, of the population

Answer 4

statistical sample

Question 5

biological population

Answer 5

the aggregation of individual organisms of a single species inhabiting a given area

Question 6

the aggregation of individual organisms of a single species inhabiting a given area

Answer 6

biological population

Question 7

entire set of data about which one wishes to draw conclusions

Answer 7

statistical population

Question 8

an entire set of measurements from a habitat, a community, a biological population, or a portion of a biological population

Answer 8

statistical population

Question 9

a portion of a larger set of data

Answer 9

statistical sample

Question 10

physical sample

Answer 10

a portion, or subset, of a collection of one or more material objects, either biotic or abiotic

Question 11

a portion, or subset, of a collection of one or more material objects, either biotic or abiotic

Answer 11

physical sample

Question 12

an example of a physical sample

Answer 12

taking 1 - liter sample of pond water

Question 13

refers to a collection of data such as measurements of the temperature or phosphate content of pond water

Answer 13

statistical sample

Question 14

when are sampling procedures biased

Answer 14

some members of the population are more likely to be recorded than others, or if the recording of some affects the recording of others

Question 15

a single value could have an uncomfortably high probability of being far from the typical or average value. Therefore…

Answer 15

a series of replicated measures should be taken

Question 16

species-sample curve

Answer 16

cumulative number of species is plotted against the cumulative number of physical samples, where each sample might be a plot

Question 17

cumulative number of species is plotted against the cumulative number of physical samples, where each sample might be a plot

Answer 17

species-sample curve

Question 18

species-area curve

Answer 18

cumulative number of species is plotted against the cumulative size of the area sampled

Question 19

cumulative number of species is plotted against the cumulative size of the area sampled

Answer 19

species-area curve

Question 20

performance curve

Answer 20

examines the mean value of a set of measurements for an ecological variable

Question 21

examines the mean value of a set of measurements for an ecological variable

Answer 21

performance curve

Question 22

example of performance curve

Answer 22

the mean density or biomass for a given species plotted as a function of the cumulative number of samples or cumulative area sampled

Question 23

plots a cumulative mean of some variable instead of the cumulative number of species

Answer 23

performance curve

Question 24

subsamples

Answer 24

portions of samples taken in the field later examined in the lab

Question 25

must be randomly taken from the sample (shaking, mixing, or blending sample) to reflect characteristics of entire sample

Answer 25

subsample

Question 26

experimental design

Answer 26

the planning of field/lab studies

Question 27

details with the questions to be asked in a study, the selection of variabls to be studied, and the choice of a sampling program.

Answer 27

experimental design

Question 28

most commonly used experimental design

Answer 28

two-sample comparison

Question 29

two-sample comparison

Answer 29

one selects two situations in which all conditions but one are equal (or nearly equal)

Question 30

Statistical methods

Answer 30

allow an ecologist to engage in three very important activities: 1. quantitatively describing/summarizing characteristics of sets of data 2. drawing conclusions about large sets of data 3. objectively assessing differences and relationships between sets of data

Question 31

parameter

Answer 31

a measure that describes or characterizes an entire population of data

Question 32

a measure that describes or characterizes an entire population of data

Answer 32

parameter

Question 33

statistics

Answer 33

descriptive measures derived from the data in samples taken from the population

Question 34

median

Answer 34

middle measurement in a ranked listing of data

Question 35

range

Answer 35

the difference between the largest and smallest data in the collection

Question 36

accuracy

Answer 36

closeness of a measured value to the true value

Question 37

if a measure is consistently high or consistently low, it is said to be

Answer 37

biased

Question 38

precision

Answer 38

the closeness of repeated measurements to each other

Question 39

the closeness of a computed estimate to the actual value being estimated

Answer 39

precision

Question 40

an interval that, with a stated level of confidence, may be said to include the population mean

Answer 40

confidence interval

Question 41

sample size is predicted to be necessary for the desired precision in estimating the mean of the population

Answer 41

iteration

Question 42

the sampling of populations in a way that enables the drawing of objective conclusions about them

Answer 42

experimental design

Question 43

experimental design

Answer 43

the sampling of populations in a way that enables the drawing of objective conclusions about them

Question 44

a measure of the variability of data within the two samples

Answer 44

pooled variance

Question 45

pooled variance

Answer 45

a measure of the variability of data within the two samples

Question 46

a statement that the two population means are the same

Answer 46

null hypothesis

Question 47

null hypothesis

Answer 47

a statement that the two population means are the same

Question 48

when is the null hypothesis rejected

Answer 48

when the computed t value is as large as the appropriate value of t

Question 49

a specific kind of symmetrical, bell-shaped distribution of measurements

Answer 49

normal distribution

Question 50

statistical testing procedures that do not depend on such assumptions of normality or equality of variances

Answer 50

nonparametric or distribution-free methods

Question 51

nonparametric or distribution-free methods

Answer 51

statistical testing procedures that do not depend on such assumptions of normality or equality of variances

Question 52

most commonly used nonparametric/distribution-free method

Answer 52

Mann-Whitney test

Question 53

one can test for differences between two populations of data by examining a sample of data from each population

Answer 53

Mann-Whitney test

Question 54

can be used in instances where t-testing is inappropriate, as well as in those where t-testing is valid

Answer 54

nonparametric methods

Question 55

census

Answer 55

the total count of all individuals in a population or other group of interests

Question 56

the total count of all individuals in a population or other group of interests

Answer 56

census

Question 57

if a sampling method tends to underestimate or overestimate a characteristic of a population or community, it is...

Answer 57

biased

Question 58

abundance

Answer 58

the number of individuals in a given area

Question 59

density

Answer 59

the abundance expressed per unit area or unit volume

Question 60

if only half the area provides suitable habitat for the speicies in question, then the species would have an _______ of 80/ha

Answer 60

ecological density

Question 61

index of density

Answer 61

the number of individuals per unit of habitat or the number of individuals per unit of habitat or number per unit area

Question 62

population intensity

Answer 62

another name for index of density

Question 63

relative species density

Answer 63

the total number of individuals of a species expressed as a proportion (percentage) of the total number of individuals of all species

Question 64

relative population density

Answer 64

the number of individuals of a given species from one location or time expressed as a proportion of the total number of individuals of that species for all locations or times sampled

Question 65

frequency

Answer 65

the number of times a given event occurs

Question 66

relative frequency

Answer 66

the frequency of that species divided by the sum of the frequencies of all species in the community

Question 67

biomass

Answer 67

the weight of the individuals of a population or group of populations and is often expressed per unit area or volume

Question 68

the proportion of the ground occuied by a perpendicular projection to the ground from the outline of the aerial parts of the members of a plant species

Answer 68

coverage

Question 69

the diameter of the crown of foliage is taken at its densest portion, and the coverage area is determined by assuming a circular outline

Answer 69

foliage cover

Question 70

generally used in a field or prairie situation and consists of measuring the circumference or the diameter of a clump of grass 2 cm to 3 cm above the ground and calculating the circular area for the foliage

Answer 70

basal coverage

Question 71

determined from the trunk circumferences measured 1.5 m above ground

Answer 71

basal areas

Question 72

the proportion of its coverage compared to that of all species in the community combined

Answer 72

relative coverage

Question 73

the degree of cover

Answer 73

dominance

Question 74

a rectagle, square, circle, or other shapes

Answer 74

plot

Question 75

used interchangeably with plot, but strictly speaking is a square or rectangle

Answer 75

quadrat

Question 76

the number of individuals in a unit area

Answer 76

density

Question 77

the number of individuals of a given species as a proportion of the total number of individuals of all species

Answer 77

relative species density

Question 78

the chance of finding a given species within a sample

Answer 78

frequency

Question 79

the frequency of a given species as a proportion of the sum of the frequencies for all species

Answer 79

relative frequency

Question 80

the proportion of the ground occupied by a vertical projection to the ground from the aerial parts of the plant

Answer 80

coverage