If a control group is not included in an experiment, it would be difficult to
1) formulate a hypothesis for the experiment
2) make observations about the experimental group
3) record data in a data table
4) draw a valid conclusion
draw a valid conclusion
Describe what an independent variable is
a variable
"I change"
something being added to be tested
Describe what a dependent variable is
data being collected from experiment
"data collected"
information from evaluation
An experiment was designed to determine if chlorophyll is responsible for the growth of corn seedlings toward light. In the experiment, equal numbers of albino corn seedlings and green corn seedlings were grown at a temperature of 24ºC. All other environmental conditions were the same for both groups of seedlings. The results of the experiment showed that both the albino seedlings and the green seedlings bent toward light.
Which hypothesis is being tested in this experiment?
1) Albino corn seedlings grow as fast as green corn seedlings.
2) Chlorophyll is needed for corn seedlings to grow toward light.
3) Differences in genotypes produce variations in corn phenotypes.
4) Light is required for germination of corn.
2) Chlorophyll is needed for corn seedlings to grow toward light.
During an investigation, a student measures out 15 grams of salt. Then, he measures 15 milliliters of water and adds the salt to it. Next, he measures a 1 centimeter wide by 4 centimeters long section of plant leaf. Which list of tools is arranged in the order that the student used them?
. What is the volume of the liquid in the graduated cylinder shown below?
1) 23 mL 2) 26 mL
3) 27 mL 4) 28 mL
2. 26mL
In an experiment, what should be the relationship between the control group and the experimental group?
1) They should be different in size
2) They should resemble each other in at least two respects
3) They should not be similar in any respect
4) They should be identical in all respects except one
They should be identical in all respects except one
An experiment was carried out to answer the question "Does the pH of water affect the growth of radish plants?" Two groups of ten radish plants were set up. One group was watered with water having a pH of 3.0, and the other group was watered with water having a pH of 7.0. Both groups of plants received the same amount and intensity of light, the same amount of water, and they were grown in the same type of soil. The heights of the radish plants were measured every 2 days for a period of 2 weeks.
19. What was the independent variable in this experiment?
1) heights of the plants
2) pH of the water
3) temperature of the water
4) type of soil
pH of water
What is the format of a hypothesis?
statement
:If...Then...
An experiment was designed to determine if chlorophyll is responsible for the growth of corn seedlings toward light. In the experiment, equal numbers of albino corn seedlings and green corn seedlings were grown at a temperature of 24ºC. All other environmental conditions were the same for both groups of seedlings. The results of the experiment showed that both the albino seedlings and the green seedlings bent toward light.
14. Which sequence of steps was most likely taken in this experiment?
1) develop a hypothesis®select suitable laboratory materials®test the hypothesis®formulate a conclusion
2) select suitable laboratory materials→formulate a conclusion→develop a hypothesis→test the hypothesis
3) develop a hypothesis→test the hypothesis→select suitable laboratory materials→formulate a conclusion
4) formulate a conclusion→select suitable laboratory materials → develop a hypothesis →test the hypothesis
1) develop a hypothesis -->select suitable laboratory materials -->test the hypothesis--> formulate a conclusion
Zebra finches are small black-and-white birds that lay eggs about the size of a bean seed. Which unit of measurement is best for accurately measuring the length of these eggs?
a) millimeters b) micrometers
c) feet d) meters
millimeters
What is the length of section A?
1) 75 mm 2) 11.5 cm
3) 4.5 cm 4) 40 mm
4.5cm
What is a constant?
factor that remains the same between the experimental group and control group
An experiment was carried out to answer the question "Does the pH of water affect the growth of radish plants?" Two groups of ten radish plants were set up. One group was watered with water having a pH of 3.0, and the other group was watered with water having a pH of 7.0. Both groups of plants received the same amount and intensity of light, the same amount of water, and they were grown in the same type of soil. The heights of the radish plants were measured every 2 days for a period of 2 weeks.
Which sentence is a possible hypothesis that was tested in this experiment?
1) Does the pH of water affect the growth of radish plants?
2) Will the amount of water alter the heights of the radish plants?
3) The temperature of the water will affect the heights of the radish plants.
4) The pH of the water will affect the heights of the radish plants.
The pH of the water will affect the heights of the radish plants.
An experiment was carried out to determine whether drinking caffeinated soda increases pulse rate. The pulse rates of two groups of people at rest were measured. Group A was then given caffeinated soda and group B was given caffeine-free soda. One hour after drinking the soda, the pulse rates were measured. The participants in the experiment were all the same age, and they were all given the same amount of soda.
What is a constant in this experiment?
1) type of soda given to each group
2) amount of caffeine given to each group
3) pulse rate of each group
4) age of participants in each group
age of participants in each group
An experiment was designed to determine if chlorophyll is responsible for the growth of corn seedlings toward light. In the experiment, equal numbers of albino corn seedlings and green corn seedlings were grown at a temperature of 24ºC. All other environmental conditions were the same for both groups of seedlings. The results of the experiment showed that both the albino seedlings and the green seedlings bent toward light.
Which is the dependent variable in this experiment?
1) type of soil
2) type of corn seedlings
3) temperature
4) growth of corn seedlings
growth of corn seedlings
Approved eye protection devices, such as goggles, are worn in the laboratory
a) to avoid eye strain
b) to improve your vision
c) only if you do not have glasses
d) any time chemicals, heat, or glassware are used
d) any time chemicals, heat, or glassware are used
The diagram below shows a wasp positioned next to a centimeter ruler. What is the length of the entire wasp (antenna to its back)?
1) 1.4 cm 2) 20 mm
3) 3.5 cm 4) 35 mm
20mm
what is a control group?
the group that does not receive the variable or the treatment
remains "normal"
How should information gathered be organized?
data tables
An experiment was carried out to determine whether drinking caffeinated soda increases pulse rate. The pulse rates of two groups of people at rest were measured. Group A was then given caffeinated soda and group B was given caffeine-free soda. One hour after drinking the soda, the pulse rates were measured. The participants in the experiment were all the same age, and they were all given the same amount of soda.
The analysis of data gathered during a particular experiment is
necessary in order to
1) formulate a hypothesis for that experiment
2) develop a research plan for that experiment
3) design a control for that experiment
4) draw a valid conclusion for that experiment
draw a valid conclusion for that experiment
A student formulated a hypothesis that cotton will grow larger bolls (pods) if magnesium is added to the soil. The student has two experimental fields of cotton, one with magnesium and one without. Identify the independent variable
1) height of the cotton plants in both fields
2) diameter of the cotton bolls in both fields
3) length of the growing season in both fields
4) amount of magnesium in the soil
amount of magnesium in the soil
Used to place water on a slide
pipette or dropper
5. A diagram of the actual size of a peppered moth wingspan is shown below.
An estimated length of the wingspan could be
1) 3 centimeters 2) 3 grams
3) 3 milliliters 4) 3 kilometers
3 centimeters
What are the steps in the Scientific Method?
- state the problem (ask a question)
- gather information
- form a hypothesis
- test the hypothesis (run the experiment)
- analyze data
- draw conclusions
- was the hypothesis supported or not?
In order to make sure your experiment is valid, what must be done?
Repeat the experiment
peer review
A student observes that an organism is green. A valid conclusion that can be drawn from this observation is that
1) the organism must be a plant
2) the organism cannot be single celled
3) the organism must be an animal
4) not enough information is given to determine whether the organism is a plant or an animal
not enough information is given to determine whether the organism is a plant or an animal
What is the dependent variable in the experiment summarized in the graph below?
1) pH
2) Temperature
3) The percent maximum activity of trypsin
4) Trypsin
The percent maximum activity of trypsin
Used to hold liquids, may not give an accurate reading for volume
beaker
3. What is the volume of the water in the graduated cylinder below?
1) 141 mL 2) 142 mL 3) 143 mL 4) 144 mL
142 mL