The negative control used in the tests for protein, lipids, sugars, and starch was
Albumin solution
Starch solution
Glucose solution
Olive oil
Distilled water
The Correct Answer is E
Choice A rationale: Albumin solution is not a negative control, but a positive control for the test for protein. Albumin is a type of protein that reacts with the biuret reagent and produces a violet color. A positive control is used to confirm that the test works and gives a positive result when the substance is present³.
Choice B rationale: Starch solution is not a negative control, but a positive control for the test for starch. Starch is a type of carbohydrate that reacts with the iodine solution and produces a blue-black color. A positive control is used to confirm that the test works and gives a positive result when the substance is present³.
Choice C rationale: Glucose solution is not a negative control, but a positive control for the test for sugar. Glucose is a type of sugar that reacts with the Benedict's solution and produces a red-orange color. A positive control is used to confirm that the test works and gives a positive result when the substance is present³.
Choice D rationale: Olive oil is not a negative control, but a positive control for the test for lipids. Olive oil is a type of lipid that reacts with the Sudan III solution and produces a red color. A positive control is used to confirm that the test works and gives a positive result when the substance is present³.
Choice E rationale: Distilled water is a negative control for the tests for protein, lipids, sugars, and starch. Distilled water is a pure solvent that does not contain any of these substances. It does not react with any of the reagents and does not produce any color change. A negative control is used to confirm that there is no response to the reagent or the microorganism used in the test. It is used to set the baseline and verify that the detecting reagent is working properly³.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is B
Explanation
Choice A rationale: Up and down is incorrect because the mechanical stage upper knob does not control the vertical movement of the stage. The vertical movement of the stage is controlled by the coarse and fine adjustment knobs, which are located on the side of the microscope. The coarse adjustment knob is used to raise or lower the stage quickly, while the fine adjustment knob is used to fine-tune the focus of the specimen.
Choice B rationale: Right and left is correct because the mechanical stage upper knob controls the horizontal movement of the stage along the x-axis. The mechanical stage is a platform that holds the slide and the specimen, and it can be moved by two knobs that are located below the stage. The upper knob moves the stage right or left, while the lower knob moves the stage forward or backward.
Choice C rationale: Back and forth is incorrect because the mechanical stage upper knob does not control the horizontal movement of the stage along the y-axis. The horizontal movement of the stage along the y-axis is controlled by the mechanical stage lower knob, which is located below the stage and next to the upper knob. The lower knob moves the stage forward or backward, while the upper knob moves the stage right or left.
Choice D rationale: All of the answer choices are correct is incorrect because only one of the answer choices is correct. The mechanical stage upper knob only causes the stage to move right or left, not up and down or back and forth. The other movements of the stage are controlled by different knobs.
Correct Answer is A
Explanation
Choice A rationale: The rate of diffusion is the speed at which particles move from an area of high concentration to an area of low concentration. This depends on the temperature, the size of the particles, and the medium they are in. Temperature affects the kinetic energy and the speed of the particles, which in turn affects the frequency and intensity of their collisions. Higher temperatures mean higher kinetic energy and faster particles, which leads to faster diffusion. ³
Choice B rationale: The change in rate of diffusion is not unaffected by temperature. Temperature is one of the main factors that influences the rate of diffusion, as explained above. Therefore, this choice is incorrect.
Choice C rationale: Diffusion does not halt when temperature is increased. On the contrary, diffusion becomes faster when temperature is increased, as explained above. Therefore, this choice is incorrect.
Choice D rationale: The change in rate of diffusion is not unpredictable when temperature is increased. There is a clear relationship between temperature and diffusion, as explained above. Therefore, this choice is incorrect.
Choice E rationale: The rate of diffusion does not decrease when temperature is increased. On the contrary, diffusion becomes faster when temperature is increased, as explained above. Therefore, this choice is incorrect..
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