What is the purpose of using PCR (polymerase chain reaction) in the laboratory?
A. To separate DNA fragments by size.
B. To amplify specific regions of DNA.
C. To sequence DNA fragments.
D. To analyze protein expression levels.
The correct answer is choice B.
To amplify specific regions of DNA.
PCR (polymerase chain reaction) is a laboratory technique used to make many copies of a specific region of DNA.
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The goal of PCR is to make enough of the target DNA region that it can be analyzed or used in some other way.
PCR has many research and practical applications, including DNA cloning, medical diagnostics, and forensic analysis of DNA.
Choice A is incorrect because PCR does not separate DNA fragments by size. Choice C is incorrect because PCR does not sequence DNA fragments.
Choice D is incorrect because PCR does not analyze protein expression levels.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: Which of the following hormones is responsible for regulating the body's metabolism and energy levels?
A. Estrogen
B. Progestin
C. Thyroxine
D. Androgen
Answer Explanation
The correct answer is choice C. Thyroxine.
Thyroxine (T4) is a hormone produced by the thyroid gland that controls your body’s metabolism, the process in which your body transforms the food you eat into energy.
Choice A, Estrogen, is not the correct answer because it is a hormone responsible for the development of female secondary sexual characteristics.
Choice B, Progestin, is not the correct answer because it is a synthetic form of progesterone used in hormonal birth control and hormone replacement therapy.
Choice D, Androgen, is not the correct answer because it is a hormone responsible for the development of male secondary sexual characteristics.
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Q #2: A nurse is caring for a patient who has suffered a traumatic brain injury after falling from a height. The nurse knows that the severity of the injury depends on the speed at which the patient hit the ground. Which of the following factors affects the terminal velocity of a falling object?
A. The shape and surface area of the object.
B. The mass and volume of the object.
C. The acceleration and momentum of the object.
D. The height and distance of the fall.
Answer Explanation
The correct answer is choice A.
The shape and surface area of the object.
The terminal velocity of an object falling through a fluid is affected by several factors, including its mass and shape.
Objects with large surface areas will often experience a large amount of air resistance when they move.
Choice B is incorrect because the volume of the object does not affect its terminal velocity.
Choice C is incorrect because the acceleration and momentum of the object do not affect its terminal velocity.
Choice D is incorrect because the height and distance of the fall do not affect the terminal velocity of a falling object.
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Q #3: Which organ in the human body is responsible for the removal of damaged red blood cells and the production of certain types of white blood cells?
A. Spleen
B. Kidneys
C. Pancreas
D. Thyroid gland
Answer Explanation
The correct answer is choice A.
The spleen is an organ in the human body that is responsible for the removal of damaged red blood cells and the production of certain types of white blood cells.
Choice B is incorrect because the kidneys are responsible for filtering waste from the blood and regulating electrolyte balance.
Choice C is incorrect because the pancreas produces hormones and enzymes that aid in digestion.
Choice D is incorrect because the thyroid gland produces hormones that regulate metabolism.
