A nurse is conducting a research study to compare the effects of two different pain medications on postoperative patients. The nurse randomly assigns the patients to either receive medication A or medication B. Which of the following is the best way to ensure that the study is valid and reliable?
A. Use a large sample size and a standardized procedure for administering the medications.
B. Use a placebo group and a double-blind technique for giving the medications.
C. Use a matched-pairs design and a crossover technique for switching the medications.
D. Use a convenience sample and a pretest-posttest design for measuring the pain levels.
The correct answer is choice B.
Using a placebo group and a double-blind technique for giving the medications is the best way to ensure that the study is valid and reliable.
A placebo group helps control for the placebo effect, which can influence the results of a study.
A double-blind technique means that neither the patients nor the researchers know which medication is being given, reducing bias.
Choice A is not the best answer because while a large sample size and standardized procedure can increase reliability, they do not address validity.
Choice C is not the best answer because a matched-pairs design and crossover technique are useful for reducing variability but do not address validity.
Choice D is not the best answer because a convenience sample may not be representative and a pretest-posttest design does not control for extraneous variables.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: What is the name of the process in which an atom loses or gains electrons to form an ion?
A. Ionization
B. Oxidation
C. Reduction
D. Isotopic decay
Answer Explanation
Ionization is the process in which an atom loses or gains electrons to form an ion.
An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.
Choice B is not the best answer because oxidation refers to the loss of electrons from an atom or molecule.
Choice C is not the best answer because reduction refers to the gain of electrons by an atom or molecule.
Choice D is not the best answer because isotopic decay refers to the process in which an unstable atomic nucleus loses energy by emitting radiation
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Q #2: A patient with chronic renal failure is undergoing hemodialysis. What process allows for the removal of waste products and excess fluid from the patient's bloodstream during hemodialysis?
A. Active transport.
B. Osmosis
C. Diffusion
D. Facilitated diffusion.
Answer Explanation
Diffusion.
During hemodialysis, waste products and excess fluids are removed from the blood by diffusion 1.
Diffusion is a separation process in which particles that are dissolved in a solution are relocated from an area of higher concentration in the blood to an area of lower concentration in the dialysate.
Choice A.
Active transport is incorrect because active transport is a process that uses energy to move molecules against a concentration gradient.
Choice B.
Osmosis is incorrect because osmosis is the movement of water molecules across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration.
Choice D.
Facilitated diffusion is incorrect because facilitated diffusion is a process where molecules move down their concentration gradient with the help of carrier proteins.
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Q #3: What is hydrogen bonding?
A. The attraction between the relatively positive areas of one molecule and the relatively negative areas of another molecule.
B. The repulsion between the positive and negative charges of two molecules.
C. The attraction between two nonpolar molecules.
D. The attraction between two ionic molecules.
Answer Explanation
Hydrogen bonding is an interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.
One atom of the pair (the donor), generally a fluorine, nitrogen, or oxygen atom, is covalently bonded to a hydrogen atom, whose electrons it shares unequally; its high electron affinity causes the hydrogen to take on a slight positive charge.
The other atom of the pair (the acceptor), also typically F, N, or O, has an unshared electron pair, which gives it a slight negative charge.
Mainly through electrostatic attraction, the donor atom effectively shares its hydrogen with the acceptor atom, forming a bond.
Choice B) The repulsion between the positive and negative charges of two molecules is incorrect because hydrogen bonding involves attraction, not repulsion.
Choice C) The attraction between two nonpolar molecules is incorrect because hydrogen bonding involves polar molecules.
Choice D) The attraction between two ionic molecules is incorrect because hydrogen bonding involves polar molecules and not ionic molecules.
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Q #4: What is the largest vein in the human body that returns deoxygenated blood from the upper half of the body to the right atrium of the heart?
A. Superior vena cava.
B. Inferior vena cava.
C. Pulmonary vein.
D. Renal vein.
Answer Explanation
The correct answer is choice A.
The superior vena cava is the largest vein in the human body that returns deoxygenated blood from the upper half of the body to the right atrium of the heart.
Choice B is incorrect because the inferior vena cava returns deoxygenated blood from the lower half of the body to the right atrium of the heart.
Choice C is incorrect because the pulmonary vein carries oxygenated blood from the lungs to the left atrium of the heart.
Choice D is incorrect because the renal vein carries deoxygenated blood from the kidneys to the inferior vena cava.
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Q #5: Which hormone is responsible for the development of female secondary sexual characteristics such as breast development, menstrual cycle, and widening of hips?
A. Progesterone
B. Testosterone
C. Estrogen
D. FSH
Answer Explanation
The correct answer is choice C. Estrogen.
Estrogen is a steroid hormone responsible for the development of female secondary sexual characteristics such as breast development, menstrual cycle, and widening of hips.
Choice A, Progesterone, is not the correct answer because it is required to maintain pregnancy and delivery.
Choice B, Testosterone, is not the correct answer because it is a hormone produced by the testes which controls the development of male secondary sexual characteristics.
Choice D, FSH (Follicle Stimulating Hormone), is not the correct answer because it stimulates the growth of ovarian follicles in females and regulates spermatogenesis in males.
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Q #6: 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 #7: In which type of tissue would you find a fibrous protein that provides strength and protection to the body, particularly in the skin, hair, and nails?
A. Keratin
B. Collagen
C. Elastin
D. Actin
Answer Explanation
The correct answer is choice A. Keratin.
Keratin is a fibrous protein that provides strength and protection to the body, particularly in the skin, hair, and nails.
It is found in epithelial tissue, which covers the body’s surface and lines its internal organs and cavities.
Choice B.
Collagen is incorrect because collagen is a fibrous protein that provides strength and support to connective tissues such as tendons, ligaments, and cartilage.
Choice C.
Elastin is incorrect because elastin is a protein that provides elasticity to tissues such as skin and blood vessels.
Choice D.
Actin is incorrect because actin is a protein that plays a role in muscle contraction and cell movement.
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Q #8: Which of the following is true regarding the role of oncogenes in cancer development?
A. Mutations in oncogenes always result in the inhibition of cell division.
B. Oncogenes are only found in human cells and not in any other organism.
C. Genes that regulate cell division are not found in any viruses.
D. Genes that regulate cell division can become oncogenes when mutated.
Answer Explanation
The correct answer is choice D.
Genes that regulate cell division can become oncogenes when mutated.
Oncogenes are mutated genes that can contribute to the development of cancer.
In their non-mutated state, everyone has genes which are referred to as proto- oncogenes.
When proto-oncogenes are mutated or increased in numbers due to DNA damage, the proteins produced by these genes can affect the growth, proliferation, and survival of the cell, and potentially result in the formation of a malignant tumor.
Choice A is incorrect because mutations in oncogenes do not always result in the inhibition of cell division.
Instead, they can contribute to the development of cancer by affecting cell growth.
Choice B is incorrect because oncogenes are not only found in human cells but can be present in other organisms as well.
Choice C is incorrect because genes that regulate cell division can be found in viruses. -
Q #9: Which of the following is a consequence of increased viscosity of a fluid?
A. Particles have a decrease in mobility.
B. The fluid will have a lower density.
C. The fluid will have a higher flow rate.
D. The fluid will have a higher pressure.
Answer Explanation
The correct answer is choice A.
An increase in viscosity of a fluid results in a decrease in mobility of particles.
Viscosity is the resistance of a fluid to a change in shape or movement of neighboring portions relative to one another.
It denotes opposition to flow and may be thought of as internal friction between the molecules.
Choice B is incorrect because an increase in viscosity does not affect the density of a fluid.
Choice C is incorrect because an increase in viscosity results in a decrease, not an increase, in flow rate.
Choice D is incorrect because an increase in viscosity does not affect the pressure of a fluid.
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Q #10: Why is water sometimes called the "universal solvent"?.
A. Because water dissolves all solutes equally well.
B. Because water is a nonpolar solvent.
C. Because water is good at dissolving ions and polar molecules.
D. Because water is poor at dissolving nonpolar molecules.
Answer Explanation
Water is sometimes called the “universal solvent” because it dissolves more substances than any other liquid.
This is due to its polarity and ability to form hydrogen bonds, which allows it to dissolve ions and polar molecules.
Choice A) Because water dissolves all solutes equally well is incorrect because water does not dissolve all solutes equally well.
Choice B) Because water is a nonpolar solvent is incorrect because water is a polar solvent.
Choice D) Because water is poor at dissolving nonpolar molecules is incorrect because it does not explain why water is called the “universal solvent”.
