Lab Manual Appendix B and C

Question 1

measurement error

Answer 1

reflects the discrepancy between our repeated measurements and the true value of the object being measured

Question 2

precision

Answer 2

the repeatability of the measurement

Question 3

accuracy

Answer 3

the tendency for the measured value to be close to, or approximate, the true accepted value

Question 4

sample size is abbreviated by

Answer 4

n

Question 5

population size is abbreviated by

Answer 5

N

Question 6

title for a graph

Answer 6

placed at bottom of a graph

Question 7

interpolation

Answer 7

a line of best fit through the data that allows you to predict values of the dependent variable for which you do not have actual data points

Question 8

extrapolation

Answer 8

the process of extending the line beyond the existing data, maintaining the trend shown by interpolation, and provides a basis for prediction

Question 9

bar graph

Answer 9

used for discrete quantitative variables which are similar but not necessarily related

Question 10

histogram

Answer 10

used exclusively for showing the distribution of data that are continuous

Question 11

statistics of location

Answer 11

describe the position of a sample along a given dimension
- most common statistics of location are the mean, median and mode; these are called measures of central tendency

Question 12

statistics of dispersion/variability

Answer 12

describe the distribution of observations.
- simplest is the range, and most common are the variance and standard deviation and standard error

Question 13

variance

Answer 13

measure of how much scatter there is around the mean

Question 14

(n-1)

Answer 14

degree of freedom. adjustment to have an unbiased estimate of the variance from a sample

Question 15

standard deviation, s

Answer 15

average size of the deviation from the mean

Question 16

standard error

Answer 16

measure of how reliable the sample mean is as an approximation to the population mean

Question 17

test of significance

Answer 17

evaluates the probability of rejecting the null hypothesis when it is actually true

Question 18

student’s t-test

Answer 18

statistical test that compares the means of two samples and assesses whether or not they differ enough to represent samples from different populations

Question 19

significance level

Answer 19

the probability of mistakenly rejecting the null hypothesis when it is true

Question 20

draw graph for t test acceptance/rejection region

Question 21

chi square test / goodness of fit /contingency

Answer 21

used to test a hypothesis in an experiment in which the data are frequency data rather than continuous date
- tests difference between observed and expected frequencies and is used for data that can be arranged into classes such as habitat, genotype, percentage

Question 22

assumptions of a chi square test

Answer 22

1. data must consist of samples taken at random from a large population
2. for each sample taken there is a restricted number of outcomes that can be divided into distinct categories
3. probabilities for each of the outcomes are independent from each other and do not change from one sampled individual to another

Question 23

draw graph for acceptance/rejection region for chi squared distribution

Question 24

when would you use a 2 x 2 contingency table?

Answer 24

when an analysis is concerned with two variables

Question 25

what did Hardy and Weinberg realise?

Answer 25

that the genotype frequencies of a population could be predicted from the frequency of the alleles, represented as p and q, using the binomial equation:

p^2 + 2pq + q^2

the above equation describes a single locus with two alleles

Question 26

what is necessarily true for the HW equation?

Answer 26

frequencies of the two alleles (p + q) must equal 1 and the frequencies of the genotypes (p^2 + 2pq + q^2) must also equal 1.

Question 27

two functions of HW equation

Answer 27

• calculate genotype frequencies of a pair of alleles at a gene locus
• predict genotype frequencies of the next generation as long as there have been no changes in the gene pool

Question 28

when there have been no changes in the gene pool, genetic equilibrium will only occur when:

Answer 28

1. population is large enough to be unaffected by random gene changes (i.e. genetic drift)
2. there is no gene flow (immigration or emigration)
3. no mutations occur or there is mutational equilibrium
4. reproduction is random (independent of genotype)
5. natural selection is not acting on a particular phenotype

Question 29

why is the concept of genetic equilibrium an important concept if in natural populations all of the conditions are almost never met?

Answer 29

significant deviations from the expected HW values provide evidence that some evolutionary force is in action. We can think of the expected HW values as a null hypothesis (no evolutionary force is acting on the population)