Question

Part 1: Read each question carefully and choose the correct answer.

1. Which statement regarding the peer review process is not correct?

The system of peer review is used to _____.

a. select the research deemed worthy of consideration by others in the field

b. give the authors feedback on the validity of methodologies and reasonableness of conclusions

c. improve the quality of the paper before it is published

d. determine conclusively the conclusions of the paper



2. Compare and contrast the three basic types of experiments. Provide an example of each one to support your statements.


Part 2: Read the passage carefully and then answer the following question.

Researchers at a major university are testing a new drug to lower cholesterol, called Choless. They started the study by testing mice. Once they received the proper FDA clearances, they began trials on humans. They began testing on males, whose ages ranged between 30 and 60 years old. The researchers split the participants into two groups. Group A was given Choless, while Group B was given placebos. A placebo is completely harmless and looks exactly like Choless, but it contains no active medicine. None of the participants knew whether they were taking Choless or the placebo. The participants were to eat a diet low in saturated fats, and high in protein and fiber. Each participant's cholesterol levels were tested and recorded every week.

Based on the passage above, determine each part of the experiment:

subject:
control:
constant:
independent variable:
dependent variable:


Part 3: Identify the independent, dependent, and constant variables for different experiments.

Note: You may have identified constant variables not mentioned in the experiment scenario. So long as these variables are reasonable (such as same weather conditions, same ambient temperature, etc.), they should be accepted as correct.

Experiment 1: A soap manufacturer runs an experiment to compare the foaming action of different dish detergents. Equal amounts of each brand of detergent are placed in identical containers half-filled with water. The water and dish detergent are at a temperature of 20°Celsius. Each container is agitated for 30 seconds, and then the height of the foam is measured.

a. independent variable:

b. dependent variable:

c. constant variable(s):



Experiment 2: A car manufacturer wants to determine the effect of weight on gas mileage for a particular model of car. The gas tanks of ten identical cars are filled with the same type of gas. Each car has a different amount of weight in its trunk. Each car is driven at the same pace around a level track for 200 miles. The amount of gasoline left in each tank is measured.

a. independent variable:

b. dependent variable:

c. constant variable(s):



Experiment 3: A biologist tests different lighting conditions for bacteria. She uses the same number of the same strain of bacteria on each petri dish, with the same type and amount of growing medium on each. Each petri dish is subjected to a different amount of light for a 24-hour period. After this time, the biologist counts the number of bacteria on each petri dish.

a. independent variable:

b. dependent variable:

c. constant variable(s):



Experiment 4: An oceanographer wishes to study the effect of salinity on the growth of a certain type of aquatic plant. Imagine an experiment the oceanographer can conduct and identify the possible variables.

a. independent variable:

b. dependent variable:

c. constant variable(s):

Answer 1

1. d

Step-by-step explanation:

The correct answer would be that the system of peer review is used to determine conclusively the conclusions of the paper.

The system of peer review refers to the process of evaluating a scientific report or paper by one or more independent scientists who have a similar background as the producer of the report or paper.

The reviewers evaluate the methodologies and various claims made by the original researcher and give feedback on their validity as well as make criticism of the paper in order to improve its quality before final publication. However, reviewers do not alter the claims or conclusions of papers, they can only query them.

Hence, options a, b, and c are correct as far as the peer review system is concerned.

The only incorrect option here is d.

2. There are 3 types of experiments, namely:

• controlled experiment
• field experiment
• natural experiment

The controlled experiment involves the comparison of experimental group with control group. The two groups are subjected to the same conditions except for the variable whose effects are being researched.

The field experiment takes place outside the laboratory settings as opposed to other types of experiments. The subjects of the field experiment are studied in their natural environment outside the lab.

The natural experiment involves studying a phenomenon naturally without having control, unlike the controlled experiment. Observations are just recorded and are used to arrive at predictions or hypotheses.

Part 2:

Subject: 30 - 60 years old males

Control: Group B, the placebo group

Constant: Diet.

Independent variable: Administered drugs (choless and placebo)

Dependent variable: cholesterol level.

Part 3

Experiment 1:

a. Independent variable: types of detergent

b. dependent variable: height of foam

c. constant variables: amount of water, container type, temperature, period of agitation.

Experiment 2:

a. independent variable: amount of weight in each car

b. dependent variable: amount of gasoline left in each car

c. constant variable: car, type of gas, speed of car, distance covered by car.

Experiment 3

a. independent variable: amount of light

b. dependent variable: number of remnant bacterial cells after exposure to light

c. constant variable: initial number of bacteria, petri dish, type/amount of growth medium.

Experiment 4

a. independent variable: level of salinity

b. dependent variable: biomass of plant

c. constant variable: type of plant, period of growth, growth conditions.