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 .
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.
Therefore, the Correct Answer is C.
More Questions on TEAS 7 Science
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Q #1: 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 #2: Which cytotoxic lymphocyte granules contain serine proteases that induce apoptosis in target cells?.
A. Perforins.
B. Cytokines.
C. Granzymes.
D. Interferons.
Answer Explanation
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.
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Q #3: 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.
