Which cytotoxic lymphocyte granules contain serine proteases that induce apoptosis in target cells?.
A. Perforins.
B. Cytokines.
C. Granzymes.
D. Interferons.
Granzymes.
Granzymes are a family of serine proteases that are stored in and secreted from the cytotoxic granules of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells.
They work in synergy with perforin, a pore-forming toxin, to induce apoptosis in target cells.
Perforin is necessary for the delivery of granzyme B to the target cell cytosol where caspase-dependent and -independent pathways to apoptosis are activated.
Perforins (choice A) are pore-forming toxins that work in synergy with granzymes to induce apoptosis in target cells.
Cytokines (choice B) are signaling molecules that regulate immune responses but do not directly induce apoptosis in target cells.
Interferons (choice D) are a type of cytokine that play a role in immune responses but do not directly induce apoptosis in target cells.
Therefore, the Correct Answer is C.
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 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.
Answer Explanation
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.
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Q #3: 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.
