Bio lab PRACTICE TEST
Assume you drink 250mL of soda out of a 1 liter soda bottle. How many liters are left?
0.75
Why are accurate measurements necessary in scientific research?
1.Being able to compare accurate results allows for good hypothesis testing.2.Being able to replicate findings is helped by taking accurate measurements.
What is the purpose of a control group in scientific experiments? A. The control group undergoes standard or no treatment and serves as a baseline for a group receiving an experimental treatment. B. It is the group that responds to an experimental treatment. C. The control group allows the experimenter to determine whether their data is statistically valid.
A
When graphing your data, it is important to A. place the dependent variable on the Y-axis. B. place the dependent variable on the X-axis. C. never try to use a bar graph. D. utilize 3-D effects to enhance the appearance of your graph.
A
Which reagent is used to detect the presence of simple sugars? A. Benedict's B. biuret C. phenol red
A
What type of graph is appropriate for displaying continuous quantitative data?
A line graph
Why does a positive Benedict test result confirm that the unknown solution originally contained starch?
A positive result indicates simple sugars (maltose) that result from starch being digested by amylase.
There are two, two-sided dishes in the pillbug experiment. In one dish, you should have placed sand in both sides. In the other dish, you should have placed ______ in one side and ______ in the other. A. cornstarch; cornstarch B. cornstarch; pillbugs C. sand; cornstarch D. sand; pillbugs E. It does not matter what is placed in the second dish.
C.
When Elodea leaves were placed in 10% NaCl, what was the result? A. The cells burst because the solution was hypotonic. B. The cell membrane did not change at all because of the protection of the cell wall. C. The cell membrane shrank away from the cell wall because the solution was hypertonic. D. The cell membrane shrank, but the central vacuole remained full. E. The cell became turgid.
C.
Why would you not use green light and white light if you wanted to determine the dependence of specific color wavelengths on the rate of photosynthesis? A. Green is absorbed and used by plants to convert light energy, white is not. B. White light is bright and green light is dim. C. White light contains all visible wavelengths, not just one color.
C.
In the yeast fermentation experiment, what is being produced to cause the air bubble at the top of the tube to increase over time? CO2 KOH H2 O2 N2
CO2
In which circumstance is food and/or beverage allowed in the laboratory? A. if containers are sealed B. if containers are kept out of sight C. if containers are covered D. never
D
The biuret test would indicate a positive result for proteins in which of the following solutions? A. olive oil B. starch solution C. glucose solution D. albumin solution E. distilled water
D.
Which color change represents a positive reaction for the presence of starch using the iodine test? A. blue to red B. blue to brownish-red C. yellow to green D. amber to blue/black E. green to red
D.
Which of the following tests requires heating prior to observing results? A. brown paper test B. Wendelspecht test C. iodine test D. Benedict's test E. biuret test
D.
Identify the dependent and independent variables in the following investigation. Coral reefs compete for light and space with seaweeds that may cover the coral like a lawn. Scientists measure the rate of coral growth in test plots with and without goby fish present.
Dependent: The rate of coral growth Independent: Plots with or without goby fish
When working with potato strips, it was important that you: A. measure the pieces of potato in millimeters. B. test the crispness of the potato immediately after exposing it to the solution. C. use a precooked potato. D. dispose of all materials in the biohazard container. E. let the potato soak in the solution for at least one hour.
E.
Why are glass beads added?
In tube 2 to make sure the volume is the sameand in tube 3 to make sure the glass beads do not effect the results
(extra) In the pill bug experiment what were the Independent and Dependent Variables?
Independent: Substance in container Dependent: number of bugs
Glucose and starch are both carbohydrates. Why does glucose produce a negative result when testing using iodine?
Iodine only tests for polysaccharides, and glucose is a monosaccharide.
Why is a 3% sodium bicarbonate (NaHCO3) solution added to each test tube?
It is a source of CO2 and H2O
Why does chlorophyll b appear yellow-green?
It reflects light in those wavelengths and absorbs violet and red.
Four test tubes containing Elodea plants, sodium bicarbonate, and topped with a volumeter were exposed to different colors of light. Which of the lines on the graph probably shows the data from a tube of Elodea exposed to green light? (see graph)
Line C, Line A and B show an increase in liquid displacement. The slope of the lines show that the rate of photosynthesis is occurring and probably means white light exposure. Line D results show oxygen levels dropping causing by oxygen consumption (cellular respiration). Line C shows a very slow rate of photosynthesis is occurring and probably means green light exposure.
Does the Enzyme Activity lab support the hypothesis: A reaction will take place if water is present? Why or why not?
No, the lab showed that catalase and hydrogen peroxide must be present for a reaction to occur.
(extra) Which type of graph best shows data that are parts of a whole?
Pie chart
(extra) A biology class wanted to study the effect of different materials on the melting rate of ice. They placed pieces of ice, each with a mass of 10g, onto trays. Group 1 was covered in plastic, group 2 was covered in paper, group 3 was covered in aluminum, and group 4 remained uncovered. Each piece of ice was allowed to melt for 15 minutes. Then final mass of the ice, minus the melted water, was recorded at the end of the experiment. What is the dependent variable in this experiment?
The final mass of the ice
(extra) A biology student wanted to study the effect of fertilizer on the growth of tomato plants. He placed four of the same type of tomato plants into separate containers, each containing the same amount of soil. Each pot received a different watering solution, containing varying amounts of fertilizer. What is the dependent variable in this experiment?
The height of the plants
Why did the different photosynthetic pigments migrate to different points on the chromatography paper?
The pigments differ in their solubility in the solvent and affinity for the paper.
What is the purpose of the chromatography solvent?
The pigments dissolve in the chromatography solvent which allows them to be seperated.
Why is the volume level for the Elodea covered with foil decreasing?
The plant is undergoing cellular respiration using glucose reserves and is consuming oxygen
(extra) A biology class wanted to study the effect of different materials on the melting rate of ice. They placed pieces of ice, each with a mass of 10g, onto trays. Group 1 was covered in plastic, group 2 was covered in paper, group 3 was covered in aluminum, and group 4 remained uncovered. Each piece of ice was allowed to melt for 15 minutes. Then final mass of the ice, minus the melted water, was recorded at the end of the experiment. What is the independent variable in this experiment?
The type of covering material
Paper chromatography was used to produce the result seen below. Which of the bands would be the least likely to absorb yellow wavelengths of light during photosynthesis?
band B (becuase the reflected wavelengths of light give the plant or flower its color. If a plant is reflecting a yellow color, then the plant is not absorbing yellow wavelengths of light)
In the metric system, what is the base unit of weight?
base unit of weight is grams
The __________ causes the stage to move upward or downward.
coarse adjustment knob
Which variables affect the rate of diffusion?
density of mediadensity of media size of molecules size of molecules concentration gradient concentration gradient membrane permeability membrane permeability
Polysaccharides are polymers composed of
sugars.
When brown iodine is exposed to starch it turns dark purple. In an experiment, you placed a cornstarch solution in a small plastic bag. Next, you placed the bag in a beaker of water containing 10 drops of iodine. If the solution in the plastic bag turned dark purple (Select all that apply)
the plastic bag was permeable to iodine, the iodine moved into the plastic bag, the plastic bag was selectively permeable.
As molecular weight increases,
the rate of diffusion decreases
The reactants of photosynthesis are
water and carbon dioxide.
Why is the volume level for the Elodea exposed to white light increasing?
producing oxygen which is distrupting the tube becuase it is going through photosynthesis
A student set up an experiment to show the effect of light color on photosynthesis in Elodea plants. She filled two test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube before placing the volumeters on the top of the tube. Why did she blow into the tube? A. to add carbon dioxide to the tube B. to add sodium bicarbonate to the tube C. to add oxygen to the tube D. to add carbohydrates to the tube
A.
Enzymes in human cells tend to perform best A. at 37°C. B. when the person has a fever. C. at 98°C. D. at 60°C. E. at 22°C.
A.
When testing tonicity of red blood cells, if the solution became transparent after adding blood cells, you could assume A. the solution was hypotonic and the cells had burst. B. the solution was hypotonic and the cells had remained intact. C. the solution was hypertonic and the cells remained intact. D. the solution was hypertonic and the cells had shrunk. E. the solution was isotonic and the cells had burst.
A.
What information did the movement of the bubble over a specified distance in the calibrated respirometer provide? (Check all that apply) A. the amount of potassium hydroxide used the amount of potassium hydroxide used B. the rate of cellular respiration the rate of cellular respiration C. the volume of oxygen used the volume of oxygen used D. the volume of carbon dioxide used the volume of carbon dioxide used E. the amount of time for the reaction to complete the amount of time for the reaction to complete
B and C
Arrange the following steps of applying immersion oil in the correct sequence. A. Focus on the specimen using the 40x objective lens. B. Turn the objectives to half way between the 40x lens and the 100x lens. C. Rotate the 100x lens over the microscope slide, and use the fine focus adjustment knob to sharpen the image. D. Apply a drop of immersion oil directly onto area of the slide you were viewing.
B, A, D, C
The negative control used in the tests for protein, lipids, sugars, and starch was A. glucose solution. B. distilled water. C. olive oil. D. albumin solution. E. starch solution.
B.
(extra) Which type of graph displays discrete categories of data?
Bar graph
A change in what component of microscopy influences the apparent size of the objects being viewed? A. light intensity B. contrast C. magnification
C.
A student set up an experiment to show that carbon dioxide is consumed by Elodea plants during photosynthesis. She filled two test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube to add carbon dioxide, which caused the distilled water to become more acidic so the phenol red turned yellow. She wrapped Tube A in aluminum foil and left Tube B exposed to the light. After 15 minutes, what should she expect to observe? A. Tube A will be red and Tube B will be yellow. B. Both tubes will have turned red. C. Tube A will be yellow and Tube B will be red. D. Both tubes will remain yellow.
C.
Changing the pH will have the following effects on a catalase-controlled reaction: A. Increasing the pH will always increase the enzyme activity. B. Decreasing the pH will always decrease the enzyme activity. C. Increasing or decreasing the pH above or below the optimum level will decrease the activity. D. Decreasing the pH will always increase the enzyme activity. E. Changing the pH will have no effect on enzyme activity
C.
In a catalase-controlled experiment, the negative control can be shown by A. catalase only. B. a mixture of water and catalase. C. a mixture of hydrogen peroxide and water. D. hydrogen peroxide only. E. a mixture of hydrogen peroxide and catalase.
C.
Why was the polyester fluff used?
To protect the seeds from touching KOH
True or false The tare button is used to zero (i.e., reset) the scale.
True
How did we make the potato and onion solution?
We added water and mashed it
Did your results while testing the effect of concentration on the rate of diffusion in a semisolid support your hypothesis? Why or why not?
Yes, I hypothesized that the higher the concentration the faster the rate of diffusion would be. So when we tested different concentrations of crystals the rate of diffusion was much faster in the concentration of 6 crystals than the one with one.
When preparing a wet mount specimen for viewing, the specimen should be covered with
a coverslip
What are molecules with a polar end and a nonpolar end that can be used to disperse lipids into polar liquids such as water called?
emulsifier
A process common to all living organisms, whether aerobic or anaerobic, is
glycolysis.