Which gland, located in the mediastinum, plays a key role in the development and maturation of T-lymphocytes?
A. Thymus
B. Parathyroid
C. Adrenal
D. Pituitary
The correct answer is choice A. Thymus.
The thymus is a primary lymphoid organ located in the mediastinum.
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It plays a key role in the maturation and differentiation of T-lymphocytes.
Choice B.
Parathyroid is incorrect because the parathyroid glands are small endocrine glands located in the neck that produce parathyroid hormone, which regulates calcium levels in the blood.
Choice C.
Adrenal is incorrect because the adrenal glands are endocrine glands located above the kidneys that produce hormones such as cortisol and adrenaline.
Choice D.
Pituitary is incorrect because the pituitary gland is an endocrine gland located at the base of the brain that produces hormones that regulate growth, metabolism, and reproductive functions.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What are the four nucleotide bases found in DNA?
A. Adenine, Thymine, Cytosine, Guanine.
B. Adenine, Thymidine, Cytidine, Guanine.
C. Adenosine, Thymine, Cytosine, Guanosine.
D. Adenosine, Thymidine, Cytidine, Guanosine.
Answer Explanation
These are the four nucleotide bases found in DNA1.
Choice B) Adenine, Thymidine, Cytidine, Guanine is incorrect because Thymidine and Cytidine are not nucleotide bases found in DNA.
Choice C) Adenosine, Thymine, Cytosine, Guanosine is incorrect because Adenosine and Guanosine are not nucleotide bases found in DNA.
Choice D) Adenosine, Thymidine, Cytidine, Guanosine is incorrect because Adenosine, Thymidine and Cytidine are not nucleotide bases found in DNA.
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Q #2: 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.
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Q #3: Which subatomic particle contributes to the positive charge of an atom?
A. Proton
B. Neutron
C. Electron
D. Nucleon
Answer Explanation
Protons contribute to the positive charge of an atom.
Protons are subatomic particles with a positive charge found in the nucleus of an atom.
Choice B is incorrect because neutrons are neutral and do not have a charge. Choice C is incorrect because electrons have a negative charge.
Choice D is incorrect because nucleons refer to both protons and neutrons, but only protons contribute to the positive charge of an atom.
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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 of the following organelles is responsible for modifying, sorting and packaging proteins and lipids?
A. Golgi apparatus
B. Mitochondria
C. Ribosomes
D. Endoplasmic reticulum
Answer Explanation
The correct answer is choice A. Golgi apparatus.
The Golgi apparatus is a membrane-bound organelle that is responsible for transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations.
Choice B is incorrect because mitochondria are responsible for energy production.
Choice C is incorrect because ribosomes are responsible for protein production.
Choice D is incorrect because the endoplasmic reticulum is responsible for lipid production and protein production, but not for modifying, sorting and packaging proteins and lipids.
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Q #6: 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 #7: Which of the following statements about bacteria and archaea is true?
A. A. Bacteria have a true nucleus while archaea do not
B. B. Archaea reproduce by spores while some bacteria reproduce by fission.
C. C. Bacteria can perform photosynthesis while archaea cannot.
D. D. Archaeal and bacterial flagella are constructed similarly.
Answer Explanation
Bacteria can perform photosynthesis while archaea cannot. Many types of bacteria can generate oxygen from sunlight through photosynthesis, while archaea cannot perform this process.
Choice A is incorrect because neither bacteria nor archaea have a true nucleus. Both are prokaryotic organisms. Choice B is incorrect because archaea reproduce by fission, fragmentation, or budding, while bacteria can produce spores and divide sexually or asexually. Choice D is incorrect because archaeal and bacterial flagella are constructed differently.
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Q #8: Which of the following represents the first line of defense to an intruding pathogen?
A. Adaptive immunity
B. Antibodies
C. Innate immunity
D. T cells .
Answer Explanation
Innate immunity represents the first line of defense to an intruding pathogen.
The innate immune system is a series of nonspecific defenses that make up the innate immune system.
These defenses are not directed against any one pathogen but instead provide a guard against all infection.
Choice A is incorrect because adaptive immunity is activated when pathogens are able to bypass innate immune defenses.
Choice B is incorrect because antibodies are part of the adaptive immune system and are produced by B cells.
Choice D is incorrect because T cells are part of the adaptive immune system and assist B cells or directly kill infected cells.
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Q #9: 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 #10: Which type of lymphocyte is capable of killing tumor cells and infected cells without prior sensitization?.
A. Helper T cells.
B. B cells.
C. Natural killer cells.
D. Cytotoxic T cells .
Answer Explanation
Natural killer cells.
Natural killer (NK) cells are large granular lymphocytes that are capable of destroying cells infected by viruses or bacteria and susceptible tumor cells without prior sensitization and restriction by MHC antigens.
Helper T cells (choice A) are a type of white blood cell that helps other immune cells respond to infections but do not directly kill infected or tumor cells.
B cells (choice B) are a type of white blood cell that produces antibodies to fight infections but do not directly kill infected or tumor cells.
Cytotoxic T cells (choice D) are a type of white blood cell that can kill infected or tumor cells but require prior sensitization to do so.
