Answer:
1. d
Explanation:
<em>The correct answer would be that the system of peer review is used to </em><em>determine conclusively the conclusions of the paper.</em>
<u>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. </u>
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.
<em>The only incorrect option here is d.</em>
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.
<u>Part 2:</u>
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.
<u>Part 3</u>
Experiment 1:
a. Independent variable: <em>types of detergent</em>
b. dependent variable: <em>height of foam</em>
c. constant variables: <em>amount of water, container type, temperature, period of agitation.</em>
<u>Experiment 2:</u>
a. independent variable: <em>amount of weight in each car</em>
b. dependent variable: <em>amount of gasoline left in each car</em>
c. constant variable: car, type of gas, speed of car, distance covered by car.
<u>Experiment 3</u>
a. independent variable: <em>amount of light</em>
b. dependent variable: <em>number of remnant bacterial cells after exposure to light</em>
c. constant variable: <em>initial number of bacteria, petri dish, type/amount of growth medium.</em>
<u>Experiment 4</u>
a. independent variable: level of salinity
b. dependent variable: biomass of plant
c. constant variable: type of plant, period of growth, growth conditions.
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