Develop a simple experiment to test the given microbes in the various salt solutions and include a method to determine growth. Predict the results of your experiment. You are provided nutrient broth cultures of the following microbes: Escherichia coli, Staphylococcus epidermidis, and Halobacterium salinarium.

The availability of water is defined by a physical parameter called the water activity, Aw. It is determined by measuring the ratio of the water vapor pressure of a solution to the water vapor pressure of pure water. The values for water activity vary between 0 and 1.0, and the closer the value is to 1.0, the more water is available to a cell for metabolic purposes.

Consider the following binomial experiment. The probability that a green jelly bean is chosen at random from a large package of jelly beans is 1/8. If Sally chooses 13 jelly beans, what is the probability that at most two will be green jelly beans?

a) 0.7781

b) 0.5000

c) 0.2800

d) 0.7841

e) 0.2159

f) None of the above.

Consider the following binomial experiment: A company owns 5 copiers. The probability that on a given day any one copier will break down is 0.64. What is the probability that at least 3 copiers will break down on a given day?

a) 0.4398

b) 0.5075

c) 0.6417

d) 0.7491

e) 0.0024

f) None of the above.

Consider the following binomial experiment: A company owns 19 copiers. The probability that on a given day any one copier will break down is 11/100. Find the mean number of copiers that will break down on any given day.

a) 0.21

b) 2.09

c) 1.73

d) 1.10

e) 1.90

f) None of the above.

We performed a final experiment where we determined the tightness of DNA packaging for this gene in wild-type toe cells, and in toe cells in which the Talon enhancer had been mutated as described for constructs g-k. In this experiment we isolated chromatin and determined if an enzyme cuts in the gene very well or very poorly, depending on how tightly packed the DNA is at the site of cutting.

c. Suggest why the ability of an enzyme to cut chromatin at a specific location might tell us about chromatin structure; specifically packing of DNA.

In this experiment, poor cutting gives a 7kb fragment of DNA, while fragments of 4kb and 3kb indicate good cutting of the DNA. The results are indicated below:

Construct                   DNA fragments observed    Chromatin structure

                                                                                    (tight, loose or intermediate)

g                                  4kb, 3kb

h and i                         7kb, 4kb, 3kb

j                                   7kb     

k                                  4kb, 3kb

d. Complete the table above to indicate the chromatin structure implied for each construct.

List the characteristics of a multinomial experiment (select all that apply):

a) The probability that the outcome of a single trial falls into a particular category remains constant from trial to trial.

b) The trials are independent.

c) The experiment consists of n identical trials.

d) The outcome of each trial falls into one of k categories.

e) Each trial results in one of only two possible outcomes.

f) The experiment contains M successes and N − M failures.

g) The probability that the outcome of a single trial falls between two categories is equal to the area under the curve between those categories.

h) The experimenter counts the observed number of outcomes in each category.

i) The number of successes is evenly distributed over all k categories.

j) Its mean is 0 and its standard deviation is 1.

k) We are interested in x, the number of events that occur in a period of time or space.

l) We are interested in x, the number of successes observed during the n trials.

As you showed on the last exam, an experiment at U of Arkansas a couple of years ago showed that the genes for CHF and RA are linked by a distance of 10.2 cM in pigs. In order to test the linkage relationship obtained by the U of Arkansas team, a U of Missouri biology team repeated the experiment making exactly the same cross, but using independently obtained pigs.

Healthy pigs: 255

CHF: 40

RA: 44

Both CHF & RA: 261

Total: 600

Conduct a chi2 test to ascertain if there is sufficient grounds for the Missouri team to reject the Arkansas linkage value. Hint: For your expected values, use the linkage estimate provided by the Arkansas researchers to calculate what the Missouri team would have expected in their experiment. Be sure to show how you calculated your X2 value, your d.f., p-value, and conclusion from your test. For expected values use to 1 decimal, for X2 values use to 2 decimals. If you reject the Arkansas hypothesis, propose an alternative explanation

Ball Drop Experiment

4. You have a class of 20 students who were conducting the ball drop experiment. The data for one student, Fernando, is given below. He noticed that his experimental values to not exactly match the expected (calculated) values. He is very concerned that he did not do the experiment correctly and is upset.  

1. Calculate a χ2 score for Fernando’s data.

2. What can you tell Fernando about his data? Should this make him feel better?

3. Maria does a chi-square calculation and gets a p-value of 0.03. She is very proud that her p-value is the lowest in the class. What can you tell Maria about her data?

Measurement, external, internal and statistical conclusion validity are the four major types of validity. What does each address, and give an example (1 or 2 sentences) of an experiment that addresses each type of validity? What are the 4 components of external validity, what does each address, and give an example (1 or 2 sentences) of an experiment that addresses each component of external validity? What are the 4 stages of participant selection/sampling and what does each address? What is the difference between a qualitative variable and a quantitative variable and give 4 examples of each? What is the difference between an independent variable and a dependent variable? Give me a simple 1 or 2 sentence study outlining the independent and dependent variables (hint: think cause and effect). 2 pts. If we were going to run an experiment that measures if rise in temperature in a classroom is related to aggression and degree of liking people, how would you operationally define the variables (hint: there are 3 – 2 dependent variables and 1 independent variable)? 2 pts.