Lab 1

Question 1

the process through which certain inherited traits become more or less common in a population because these traits are associated with reproductive success (or …) is called …

Answer 1

fitness; natural selection

Question 2

to measure variation, we have to identify …, or … which we can evaluate in some quantitative way

Answer 2

discrete properties; traits

Question 3

analyzing variation entails … variation as the starting point, with the second step being to identify the … we see in nature

Answer 3

measuring; source of variation

Question 4

much biological variation, especially among individuals of the same species, is … in origin

Answer 4

environmental

Question 5

the second main source of variation is … in origin

Answer 5

genetic

Question 6

genetic differences are … and are therefore subject to …

Answer 6

heritable; natural selection

Question 7

genetic variation may exist for a trait that is also influenced by environmental factors. we then say that the trait exhibits a … x … interaction

Answer 7

genotype; environment

Question 8

some traits are quantified by counting them. the entity is either present/not present. these are … traits

Answer 8

discrete

Question 9

other traits are measured on a … scale. values for the trait in this case can take fractional measurements

Answer 9

continuous

Question 10

commonalities btwn discrete and continuous traits:

1. they can take a wide variety of values
2. a value of zero means something real
3. there is a … in values

Answer 10

ranking

Question 11

… variables are variables that are ranked, but not measured in a precise way

Answer 11

ordinal

Question 12

… or … variables include things like sex, color, presence/absence of wings etc. for such variables, we cannot compute an average. . the same is true of ordinal variables

Answer 12

categorical; nominal

Question 13

limits on size and shape affecting the performance of a biological trait are called … and they help to explain why many species’ characteristics remain within predictable ranges

Answer 13

functional constraints

Question 14

we use a … of individuals to represent the whole

Answer 14

sample

Question 15

researchers try to avoid …, or sampling flaws that overrepresent individuals of one type and under represent others

Answer 15

bias

Question 16

mu is used for the …

Answer 16

unknown mean

Question 17

models and tests based on a normal curve are called … statistics

Answer 17

parametric

Question 18

… tests are developed for non-standard curves

Answer 18

non-parametric

Question 19

the sample size must be large enough to eliminate … due to chance departures from the population mean

Answer 19

sampling errors

Question 20

to measure the amount of variation around the mean we use a statistic called the …

Answer 20

standard deviation

Question 21

the … is the square of the standard deviation

Answer 21

variance

Question 22

a difference is considered … when it is found to be unlikely to be due to chance

Answer 22

statistically significant

Question 23

the … is a default explanation which states that nothing interesting has been observed, that there is no relationship between two variables, or that there is no diference between groups

Answer 23

null hypothesis

Question 24

if the test provides a probability or p-value equal or less than …, we reject the null hypothesis and accept an alternative hypothesis

Answer 24

0.05

Question 25

the … test is used to determine whether there is a significant difference in the mean value of some variable between two different groups the null hypothesis of one of these tests is that there is no difference in the variable between the groups

Answer 25

t