BSC 117: Final Practical Study Guide

What is the null hypothesis (H0)?

A statement in which there is no relationship between two variables

What is the alternative hypothesis (Ha)?

A statement in which there is some statistical significance between two measured phenomena

When would you use a chi-squared test?

you compare an observed set of numbers to an expected set

When would you use a t-test?

2 populations, 1 variable is changed; the independent variable is either present (with) or absent (without)

What are the two types of t-test?

• Type 1 (paired): the same subjects are used in “without” and “with” groups

• Type 2: different subjects are used in the “without” and “with” groups, but the variances of the two groups are equal

What are the two tail types for a t-test?

• 1-tailed: directional

• 2-tailed: non-directional

What formula would you use for a t-test?

=t.test (B4:B13, C4:C13, 2, 2)

What formula would you use for a chi-squared test?

=chisq.test (C3:C8, D3:D8)

If the p-value is (x), what would you conclude about the hypothesis?

• p-value ≤ 0.05 reject H0 (null hypothesis); there is a low probability that both datasets come from the same population

• p-value > 0.05 fail to reject H0; there is a high probability that both datasets come from the same population

What is the best way to graph this data?

Scatterplot

What is the control group?

the group used to show what happens under normal conditions, without the experimental manipulation

What is the experimental group?

the group in an experiment that receives the treatment, manipulation, or independent variable you are testing

What are the controls of the experiment?

the variables you keep constant on purpose so they do not influence your results

Gram positive

(purple) there is a cytoplasmic membrane surrounded by a very thick cell wall composed of many layers of peptidoglycan that are heavily cross-linked; typically less resistant to antibiotics

Gram negative

(pink) there is a cytoplasmic membrane, a periplasmic space, a thin cell wall composed of only a few layers of peptidoglycan that are partially cross-linked and enclosed by an outer membrane; typically more resistant to antibiotics

Xylem

moves water and minerals from roots up the plant; lignified cell walls look thick with a diameter is larger than tracheids

Phloem

moves sugars (glucose, sucrose) and organic molecules; living cells containing peripheral cytoplasm, but not a nucleus; thin-walled and usually smaller diameter (not lignified)

What is A?

Frog heart

What is B?

Frog lung

What is J?

Frog liver

What is 2?

Rat heart

What is 1?

Rat liver

What is 6?

Rat kidney

What is 2?

Mussel gills

What is 8?

Mussel foot

What is 1?

Mussel mantle

Look at two locations and know which is probably more biodiverse

The location with more species and a more even spread of those species is more biodiverse. More habitat complexity (forest, wetland) = higher biodiversity

Which of two locations has lower species richness?

The location with fewer different species has lower species richness

In detail, how would you collect data on species richness?

To collect data on species richness, you sample each location in a standardized way (quadrants/transects), list all different species found, and compare the total number of species between locations

In detail, how would you estimate population size?

To estimate population size, you sample part of the population (mark-recapture), calculate density or proportion, and then scale up using a formula to estimate the total number of individuals.

Know how to read the flow chart from the endocrinology lab

an increase in organ size means look up the pathway, and decrease in organ size means look down the pathway