How do neurons communicate with each other?
A. Through electrical signals only
B. Through chemical signals only
C. Through electrical and chemical signals
D. Through mechanical signals only.
Neurons communicate with each other through both electrical and chemical signals.
The electrical signal, or action potential, runs from the cell body area to the axon terminals, through a thin fiber called axon.
Neurons also communicate with one another at junctions called synapses.
At a synapse, one neuron sends a message to a target neuron—another cell.
Most synapses are chemical; these synapses communicate using chemical messengers.
Choice A is incorrect because neurons communicate not only through electrical signals but also through chemical signals.
Choice B is incorrect because neurons communicate not only through chemical signals but also through electrical signals.
Choice D is incorrect because neurons do not communicate through mechanical signals.
Therefore, the Correct Answer is C.
More Questions on TEAS 7 Science
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Q #1: What is a primer in DNA sequencing?
A. A short piece of double-stranded DNA that binds to the template DNA and acts as a "starter" for the polymerase.
B. A short piece of double-stranded DNA that binds to the primer and acts as a "starter" for the template.
C. A short piece of single-stranded DNA that binds to the template DNA and acts as a "starter" for the polymerase.
D. A short piece of single-stranded DNA that binds to the polymerase and acts as a "starter" for the template.
Answer Explanation
A primer is a short single-stranded DNA fragment used in certain laboratory techniques, such as the polymerase chain reaction (PCR).
In the PCR method, a pair of primers hybridizes with the sample DNA and defines the region that will be amplified.
Choice A) A short piece of double-stranded DNA that binds to the template DNA and acts as a “starter” for the polymerase is incorrect because primers are single-stranded, not double-stranded.
Choice B) A short piece of double-stranded DNA that binds to the primer and acts as a “starter” for the template is incorrect because it does not make sense for a primer to bind to itself.
Choice D) A short piece of single-stranded DNA that binds to the polymerase and acts as a “starter” for the template is incorrect because primers bind to the template DNA, not to the polymerase.
Note: DNA primers are used instead of RNA primers in DNA sequencing and PCR because DNA is more stable, specific, and compatible with the enzymes and processes involved in these techniques.
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Q #2: What is the function of inflammatory cytokines released during the early response to bacterial infection?
A. Enhancing the phagocytosis of pathogens and disrupting the infection
B. Attacking invading pathogens
C. Initiating cell recruitment and local inflammation
D. Secreting antibodies to neutralize pathogens .
Answer Explanation
Inflammatory cytokines released during the early response to bacterial infection play a crucial role in initiating cell recruitment and local inflammation 1.
They induce the expression of adhesion molecules in endothelial cells and promote the recruitment of neutrophils to the site of inflammation 1.
Choice A is incorrect because while inflammatory cytokines may enhance phagocytosis, they do not directly disrupt the infection.
Choice B is incorrect because inflammatory cytokines do not directly attack invading pathogens.
Choice D is incorrect because inflammatory cytokines do not secrete antibodies to neutralize pathogens.
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Q #3: During the menstrual cycle, which structure in the ovary produces progesterone to prepare the endometrium for potential implantation?
A. Corpus luteum.
B. Fimbriae
C. Follicle
D. Ovarian ligament.
Answer Explanation
Corpus luteum.
During the menstrual cycle, the corpus luteum in the ovary produces progesterone to prepare the endometrium for potential implantation.
Choice B is incorrect because fimbriae are finger-like projections at the end of the fallopian tubes that help guide the egg into the tube.
Choice C is incorrect because a follicle is a sac in the ovary that contains an immature egg.
Choice D is incorrect because the ovarian ligament is a fibrous band of tissue that connects the ovary to the uterus.
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Q #4: Which of the following is an example of a storage form of glucose in the human body?
A. Starch
B. Glycogen
C. Fructose
D. Cellulose
Answer Explanation
Glycogen is the storage form of glucose in the human body.
It is a polysaccharide that is stored primarily in the liver and muscle tissue and can be broken down into glucose when the body needs energy.
Choice A is incorrect because starch is a storage form of glucose in plants, not in the human body.
Choice C is incorrect because fructose is a simple sugar, not a storage form of glucose.
Choice D is incorrect because cellulose is a structural carbohydrate found in plant cell walls, not a storage form of glucose in the human body.
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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: What is a control group used for in scientific studies?
A. To establish causality by isolating the effect of an independent variable.
B. To establish the effect of a dependent variable on an independent variable.
C. To control the impact of extraneous variables on the dependent variable.
D. To control the impact of extraneous variables on the independent variable.
Answer Explanation
A control group is used in scientific studies to establish causality by isolating the effect of an independent variable.
The control group serves as a baseline or comparison group that does not receive the treatment or intervention being tested.
By comparing the results of the control group to the experimental group, researchers can determine if any observed changes are due to the independent variable or if they are due to chance or other factors.
Choice B is incorrect because a control group is not used to establish the effect of a dependent variable on an independent variable.
Choice C is incorrect because while a control group can help control for the impact of extraneous variables on the dependent variable, its primary purpose is to isolate the effect of the independent variable.
Choice D is incorrect because a control group is not used to control for the impact of extraneous variables on the independent variable.
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Q #7: A patient with a history of heart failure is prescribed a medication that increases urine output to reduce fluid buildup. Which of the following statements best describes the mechanism of action of the prescribed medication?
A. Inhibits the renin-angiotensin-aldosterone system.
B. Blocks beta receptors.
C. Increases sodium and water reabsorption.
D. Enhances glomerular filtration rate.
Answer Explanation
The correct answer is choice D - Enhances glomerular filtration rate.
The medication prescribed to the patient is a diuretic, which removes water and electrolytes from the body by increasing urination 1.
This helps reduce fluid buildup in the body.
Choice A, Inhibits the renin-angiotensin-aldosterone system, is not the correct answer because it describes a different mechanism of action.
Choice B, Blocks beta receptors, is not the correct answer because it describes a different mechanism of action.
Choice C, Increases sodium and water reabsorption, is not the correct answer because it would have the opposite effect of reducing fluid buildup.
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Q #8: What is the normal flora?
A. A variety of microbial species found in certain areas of the human body.
B. A group of infectious parasites that cause diarrheal diseases.
C. The genetic material of bacteria housed within a true nucleus.
D. The protein coat surrounding the viral genome.
Answer Explanation
The normal flora refers to the microbial community that colonizes on the skin and mucus membrane .
Normal flora can be found in many sites of the human body including the skin, respiratory tract, urinary tract, and the digestive tract.
Choice B is incorrect because normal flora does not refer to a group of infectious parasites that cause diarrheal diseases .
Choice C is incorrect because normal flora does not refer to the genetic material of bacteria housed within a true nucleus .
Choice D is incorrect because normal flora does not refer to the protein coat surrounding the viral genome .
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Q #9: 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”.
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Q #10: In a well-designed experiment, all variables apart from the treatment should be kept constant between what?.
A. Control group and treatment group.
B. Independent variable and dependent variable.
C. Experimental group and non-experimental group.
D. High level and low level of the independent variable.
Answer Explanation
In a well-designed experiment, all variables apart from the treatment should be kept constant between the control group and treatment group.
This means researchers can correctly measure the entire effect of the treatment without interference from confounding variables.
Choice B) Independent variable and dependent variable is incorrect because these are not groups but rather variables.
The independent variable is manipulated by the experimenters while the dependent variable is measured to see if it changes as a result of the manipulation.
Choice C) Experimental group and non-experimental group is incorrect because a non-experimental group is not a term used in experimental design.
The correct term for the group that does not receive the treatment is control group.
Choice D) High level and low level of the independent variable is incorrect because these are levels of the independent variable, not groups.
In an experiment, there can be multiple levels of the independent variable, but they are applied to different groups (e.g.
control group, treatment group).
