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WorksheetsLab Quiz 3: Scientific Method, EV, CER
Total questions: 25
Worksheet time: 1hrs 17mins
Use the following paragraph to answer questions 1 and 2. Encircle the correct number of choice.
In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed that a mold called Penicillium was also growing in some of the dishes. Petri dish A represents a dish containing only Staphylococcus bacteria. In dishes containing the Penicillium mold, represented by Petri dish B, Fleming noticed that a clear area existed around the mold because all the bacteria in this area had died. In the culture dishes without the mold, no clear areas were present. Fleming suggested that the mold was producing a chemical that killed the bacteria. He decided to isolate this substance and test it to see if it would kill bacteria. Fleming grew some Penicillium mold in a nutrient broth. After the mold grew in the broth, he removed all the mold from the broth and added the broth to a culture of bacteria. All the bacteria died.
Which of the following statements is a reasonable expression of Fleming's hypothesis?
Nutrient broth kills bacteria.
There are clear areas around the Penicillium mold where Staphylococcus doesn't grow.
Mold kills bacteria.
Penicillium mold produces a substance that kills Staphylococcus.
Without mold in the culture dish, there were no clear areas in the bacteria.
2. Fleming grew Penicillium in broth, removed the Penicillium, and poured the broth into culture dishes containing bacteria to see if the broth would kill the bacteria. What step in the scientific method does this represent?
Collecting and organizing data
Making a hypothesis
Testing a hypothesis by experiment
Rejecting the old hypothesis and making a new one
A scientific investigation is not valid unless every step in the scientific method is present and carried out in the exact order listed in this chapter.
True
False
Which of the following is closest in meaning to the word “hypothesis”?
Fact
Law
Educated guess
Theory
Use the following paragraph to answer questions 5 through 9.
Gary noticed that two plants of the same type were different in size after three weeks, even though they were initially the same size when his mother planted them on the same day. Since the larger plant was in the full sun all day and the smaller plant was in the shade of a tree for most of the day, Gary believed that the sunshine was responsible for the difference in plant size. In order to test this, Gary bought ten small plants of the same size and type. He also made sure they have the same amount and type of soil. Gary then built a frame to hold a canvas roof over five of the plants, while the other five were nearby but out in the sun. Gary was careful to make sure that each plant received exactly the same amount of water and plant food every day.
Which of the following is a reasonable statement of Gary's hypothesis?
Different plants have different characteristics.
Plants that get more sunshine grow larger than plants that get less sunshine.
Plants that grow in the shade grow larger.
Plants that don't receive water will die.
Plants that receive the same amount of water and plant food will grow the same amount.
What scientific reason might Gary have for insisting that the container size for the all plants be the same?
Gary wanted to determine if the size of the container would affect the plant growth.
Gary wanted to make sure the size of the container did not affect differential plant growth in his experiment.
Gary wanted to control how much plant food his plants received.
Gary wanted his garden to look organized.
What scientific reason might Gary have for insisting that all plants receive the same amount of water every day?
Gary wanted to test the effect of shade on plant growth, and therefore he wanted to control variables other than the amount of sunshine on the plants.
Gary wanted to test the effect of the amount of water on plant growth.
Gary's hypothesis was that water quality was affecting plant growth.
Gary was conserving water.
There is no possible scientific reason for having the same amount of water for each plant every day.
What was the variable being tested in Gary's experiment?
The amount of water
The difference in the growth of plant
The amount of soil
The amount of sunshine
The type of soil
Which of the following factors did Gary not control in his experimental setup that may be varying?
Individual plant variation
Soil temperature due to the different colors of the containers
Water loss due to evaporation from the soil
The effect of insects, which may attack one set of plants but not the other
All of the above are possible factors that Gary did not control
A hypothesis is:
a description of a consistent pattern in observations.
an observation that remains constant.
a theory that has been proven.
a tentative explanation for a phenomenon.
A number of people became ill after eating oysters in a restaurant. Which of the following statements is a hypothesis about this occurrence?
Everyone who ate oysters got sick.
People got sick whether the oysters they ate were raw or cooked.
Symptoms include nausea and dizziness.
The cook felt really bad about it.
Bacteria in the oysters may have caused the illness.
Which statement best describes the reason for using experimental controls?
Experimental controls eliminate the need for large sample sizes.
Experimental controls eliminate the need for statistical tests.
Experimental controls reduce the number of measurements needed.
Experimental controls allow comparison between groups that are different in on one variable.
13. A student decides to set up an experiment to determine the relationship between the growth rate of plants and the presence of detergent in the soil. He sets up ten seed pots. In five of the seed pots, he mixes a precise amount of detergent with the soil. The other five seed pots have no detergent in the soil. The five seed pots with detergent are placed in the sun, and the five seed pots with no detergent are placed in the shade. All ten seed pots receive the same amount of water as well as the same number and type of seeds. He grows the plants for two months and charts the growth every two days. What is wrong with his experiment?
The student has too few pots.
The student has two variables different between the groups.
The student did not add detergent to all ten pots.
The student has no experimental control on the soil.
A scientist plants two rows of corn for experimentation. She puts fertilizer on row 1 but does not put fertilizer on row 2. Both rows receive the same amount of sun and water. She checks the growth of the corn over the course of five months. What is acting as the control in this experiment?
The corn without fertilizer
The corn with fertilizer
The amount of water
The height of the corn plants
If you have a control group for your experiment, which of the following is true?
There can be more than one difference between the control group and the test group but no more than three differences, or else the experiment is invalid.
The control group and the test group may have many differences between them.
The control group must be identical to the test group except for one variable.
None of these are true.
If the hypothesis is rejected by the experiment, then:
the experiment may have been a success.
the experiment was a failure.
the experiment must be poorly designed.
the experiment didn't follow the scientific method.
After scientists analyze the results of their experiments, they ____.
form hypotheses
include a control
communicate those results to other people
choose the variables they want to test
Which of the following steps to solve a problem must be completed first?
analyzing data
recognizing and identifying the problem
forming a hypothesis
testing a hypothesis
Which of the following steps to solve a problem is completed last?
analyzing data
recognizing and identifying the problem
drawing conclusions
testing a hypothesis
A prediction or statement that can be tested is a(n)____.
conclusion
observation
control
hypothesis
A factor in an experiment that can change is a(n)____.
observation
variable
control
hypothesis
A sample that is treated exactly like the other experimental groups except that the variable is not applied to it is a(n) ____.
observation
variable
control
hypothesis
Student 1
If 2 samples have the same values for all 5 properties, these data could be used to predict which samples are composed of the same substance.
Student 2
If 2 samples have the same values for any 3 or more of the 5 properties, they are composed of the same substance. If 2 samples have the same values for fewer 3 of the 5 properties, they are composed of different subdtance.
Student 3
If 2 samples have the same mass, volumes, and density, they are composed of the same substance. If 2 samples have the different values for any of these 3 properties, they are composed of different substance. Neither melting point nor boiling point, by itself, can distinguish between substance.
Student 4
If 2 samples have the same density, melting point, and boiling point, they are composed of the same substance. If 2 samples have different values for any of these 3 properties, they are composed of different substances. Neither mass nor volume, by itself, can distinguish between substances.
Based on Student 1 explanation, the same substance composes both of the samples in which of the following pairs?
Sample A and B
Sample B and C
Sample C and D
Sample D and E
Student 1
If 2 samples have the same values for all 5 properties, these data could be used to predict which samples are composed of the same substance.
Student 2
If 2 samples have the same values for any 3 or more of the 5 properties, they are composed of the same substance. If 2 samples have the same values for fewer 3 of the 5 properties, they are composed of different subdtance.
Student 3
If 2 samples have the same mass, volumes, and density, they are composed of the same substance. If 2 samples have the different values for any of these 3 properties, they are composed of different substance. Neither melting point nor boiling point, by itself, can distinguish between substance.
Student 4
If 2 samples have the same density, melting point, and boiling point, they are composed of the same substance. If 2 samples have different values for any of these 3 properties, they are composed of different substances. Neither mass nor volume, by itself, can distinguish between substances.
Based on Student 3's explanation, the same substance composes both of the samples in which of the following pairs?
Samples A and C
Samples B and E
Samples F and G
Samples G and H
Student 1
If 2 samples have the same values for all 5 properties, these data could be used to predict which samples are composed of the same substance.
Student 2
If 2 samples have the same values for any 3 or more of the 5 properties, they are composed of the same substance. If 2 samples have the same values for fewer 3 of the 5 properties, they are composed of different subdtance.
Student 3
If 2 samples have the same mass, volumes, and density, they are composed of the same substance. If 2 samples have the different values for any of these 3 properties, they are composed of different substance. Neither melting point nor boiling point, by itself, can distinguish between substance.
Student 4
If 2 samples have the same density, melting point, and boiling point, they are composed of the same substance. If 2 samples have different values for any of these 3 properties, they are composed of different substances. Neither mass nor volume, by itself, can distinguish between substances.
Supposed that the temperature of Sample A is increaseds to 250 C at 1 atm of pressure. at 250 C, would Sample A be a solid or a liquid?
Solid
Liquid
gas
none of these
