Question

1. a researcher reviewing another scientists experiment would most likely consider it valid if 1 the conclusions were not based on the observations 2 there was an experimental group but no control group 3 the sample size was extremely small 4 other researchers were able to duplicate the results 9. an experimental setup is shown in the diagram below. which hypothesis would most likely be tested using this setup? 1 water plants release a gas in the presence of light. 2 roots of plants absorb minerals in the absence of light. 3 green plants need light for cell division. 4 plants grow best in the absence of light. 10. which statement best describes a scientific theory? 1 it is a collection of data designed to provide support for a prediction. 2 it is an educated guess that can be tested by experimentation. 3 it is a scientific fact that no longer requires any evidence to support it. 4 it is a general statement that is supported by many scientific observations. 11. an experiment was carried out to determine which mouthwash was most effective against bacteria commonly found in the mouth. four paper discs (a through d) were each dipped into a different brand of mouthwash. the discs were then placed onto the surface of a culture plate that contained food, moisture and bacteria commonly found in the mouth. the following diagram shows the growth of bacteria on the plate after 24 hours. which change in procedure would have improved the experiment? 1 using a smaller plate with less food and moisture 2 using bacteria from many habitats other than the mouth 3 using the same size paper discs for each mouthwash 4 using the same type of mouthwash on each disc 12. which source would provide the most reliable information for use in a research project investigating the effects of antibiotics on disease - causing bacteria? 1 the local news section of a newspaper from 1993 2 a news program on national television about antigens produced by various plants 3 a current professional science journal article on the control of pathogens 4 an article in a weekly news magazine about reproduction in pathogens 13. researchers performing a well - designed experiment should base their conclusions on 1 the original hypothesis of the experiment 2 data from repeated trials of the experiment 3 a small sample size to ensure valid results of the experiment 4 results predicted before performing the experiment 14. a scientist is planning to carry out an experiment on the effect of heat on the function of a certain enzyme. which would be the least appropriate first step to take? 1 doing research in a library or on the internet 2 having discussions with other scientists 3 completing a data table of expected results 4 using what is already known about the enzyme

Explanation:

• Question 8: A valid experiment can be replicated by others. If results can be duplicated, it adds to the experiment's credibility.
• Question 9: The setup with water - plants and light suggests testing the release of a gas by water plants in the presence of light.
• Question 10: A scientific theory is a general statement supported by many scientific observations.
• Question 11: Using the same size paper discs for each mouthwash would be a way to control a variable in the experiment.
• Question 12: A current professional science journal article is the most reliable source for scientific research.
• Question 13: Conclusions in a well - designed experiment should be based on data from repeated trials.
• Question 14: Completing a data table of expected results before starting an experiment is the least appropriate first step as it should be based on research and prior knowledge, not just expectations.

Answer:

1. 4. other researchers were able to duplicate the results
2. 1. Water plants release a gas in the presence of light.
3. 4. It is a general statement that is supported by many scientific observations
4. 3. using the same size paper discs for each mouthwash
5. 3. a current professional science journal article on the control of pathogens
6. 2. data from repeated trials of the experiment
7. 3. completing a data table of expected results