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Living Environment Regents August 2010 Question 75 |
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NYS Living Environment Regents August 2010
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Correct answer: (3) Diffusion
Diffusion is the spontaneous tendency of a substance to move from an area with high concentration to an area of low concentration. Since the concentration of glucose and starch is higher inside the artificial cell, it is expected that the glucose and starch molecules would move out of the artificial cell to reach equilibrium in concentration. This movement will be manifested by the change in the color of the outside solution due to the presence of the starch indicator.
Incorrect answer:
(1) carbohydrate synthesis
Carbohydrate synthesis is the process of forming carbohydrate structures. In living organisms, this occurs naturally. For instance, during dark reactions in plants, adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH) are used to convert carbon dioxide into carbohydrate. This is a complex process, thus the setup above cannot represent carbohydrate synthesis.
(2) active transport
Active transport is another type of substance movement across a biological membrane against a concentration gradient with the help of energy and transport proteins. There was no energy input illustrated in this setup.
(4) dehydration
Dehydration refers to the excessive removal of water from the body. Water was not removed from the setup, thus, the illustration does not represent dehydration.
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Living Environment Regents August 2010 Question 74 |
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NYS Living Environment Regents August 2010
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Correct answer: (2) starch did not pass out of the artificial cell
There might be a negligible concentration of starch in the cell to facilitate transport of starch out of the artificial cell.
Incorrect answers:
(1) glucose moved from the artificial cell into the beaker
If the glucose molecules moved out of the artificial cell, then the color of the outside solution should have changed due to the presence of starch indicator.
(3) starch was digested to glucose in the artificial cell
This cannot occur due to the absence of enzymes that will breakdown the bonds in the starch to yield glucose molecules.
(4) glucose molecules combined to produce starch in the artificial cell
This will only occur if the hydrogen atoms are removed from the glucose.
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Living Environment Regents August 2010 Question 73 |
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NYS Living Environment Regents August 2010
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The artificial cell has a semi-permeable membrane, thus the glucose and the starch molecules could move out of the artificial cell by diffusion. Diffusion is the spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area. When the starch molecules reach the solution outside the artificial cell, then the starch indicator would react with the starch molecules and will turn the solution into a dark blue color.
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Living Environment Regents August 2010 Question 70 |
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NYS Living Environment Regents August 2010
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The researcher should have measured the number of times the second group could squeeze the clothespin prior to the exercise so that he could compare it with the number of squeezes after the exercise. On the other hand, the first group should also do two one-minute takes of squeezing. The results of the first trial of each group must be compared with the second trial. If the results of the first and second trials of the first group are the same, then the hypothesis could be false. If the results of the first and second trials of the second group are different, then the hypothesis could be true.
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Living Environment Regents August 2010 Question 69 |
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NYS Living Environment Regents August 2010
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Correct answer: (3) pulse rate of each group
The dependent variable refers to the variable that is influenced by the changes in the independent variable. In this experiment, the independent variable is the soda. The researcher is testing the effect of the absence or presence of caffeine on pulse rate.
Incorrect answers:
(1) type of soda given to each group
The type of soda is the independent variable because it is not affected by the other variable, which is the pulse rate.
(2) amount of soda given to each group
The amount of soda is constant among the groups; thus, it is not the dependent variable.
(4) age of participants in each group
The age of the group does not change with the manipulation of the independent variable.
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Living Environment Regents August 2010 Question 68 |
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NYS Living Environment Regents August 2010
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Correct answer: (3) control group
In the experiment, all the participants listened to music. The researcher should have added another group to serve as the control. The control group will not listen to the different types of music, but their pulse rates will be recorded every 30 seconds. If the pulse rates of the control group and the experimental group (persons that listened to the music) are different, then the conclusion is valid.
Incorrect answers:
(1) prediction
The prediction is the specific ways of how to test whether a hypothesis is true. In the given scenario, the prediction is indicated in this sentence: She thought that pulse rate would change with different types of music.
(2) hypothesis
The hypothesis is the trial answer to a stated problem based on pertinent facts found in previous studies. It might not be indicated that she did research about previous studies, but it is very likely that she came up with the hypothesis that listening to different types of music would affect pulse rate after doing some observations or research.
(4) research plan
The researcher has a research plan, which is indicated in this sentence: Each person participating in her experiment listened to seven different selections of music for 30 seconds each. The pulse rates were taken after each 30-second interval of music.
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Living Environment Regents August 2010 Question 67 |
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NYS Living Environment Regents August 2010
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Correct answer: (1) paper chromatography
Paper chromatography is a laboratory technique used to separate substances with different rates of migration across a sheet of paper. The paper is initially placed in a particular solvent to create a stationary liquid phase. Then the test solution is dropped near the edge of the paper (indicated in the illustration as the original spot). Then the tip is dipped in another solvent to allow the movement of the components of the test solution based on the sizes of the molecules and their solubility in the solvent.
Incorrect answers:
(2) gene manipulation
Gene manipulation, also known as genetic engineering, is a process that involves the use of various laboratory tools and enzymes to cut out, insert, and alter pieces of the DNA that contain one of more genes of interest.
(3) dissection
Dissection is a process usually used in anatomy, wherein the external parts are disassembled, by cutting or slicing, to analyze the structure and function of the internal body parts of an organism.
(4) staining
Staining refers to the laboratory technique that uses stains or dyes to adjust the contrast of samples to be viewed through laboratory equipment, such as the microscope. This can be used for better viewing of the various parts and components of the samples under the microscope. It can also be used to determine if a specific type of molecule is present in a sample. For example, iodine is used to determine the presence of starch in a sample, indicated by the dark blue coloration.
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Living Environment Regents August 2010 Question 54 |
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Living Environment Regents August 2010 Question 53 |
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Living Environment Regents August 2010 Question 52 |
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