What is the function of inflammatory cytokines released during the early response to bacterial infection?

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.

Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens.

PRRs play a crucial role in the proper function of the innate immune system and are germline-encoded host sensors, which detect molecules typical for the pathogens.

Choice B is incorrect because cytokines are not receptors but rather signaling molecules that regulate immunity.

Choice C is incorrect because chemokines are not receptors but rather signaling molecules that attract immune cells to sites of infection.

Choice D is incorrect because T cells are not receptors but rather white blood cells that assist B cells or directly kill infected cells.

The correct answer is choice B.

To amplify specific regions of DNA.

PCR (polymerase chain reaction) is a laboratory technique used to make many copies of a specific region of DNA.

The goal of PCR is to make enough of the target DNA region that it can be analyzed or used in some other way.

PCR has many research and practical applications, including DNA cloning, medical diagnostics, and forensic analysis of DNA.

Choice A is incorrect because PCR does not separate DNA fragments by size. Choice C is incorrect because PCR does not sequence DNA fragments.

Choice D is incorrect because PCR does not analyze protein expression levels.

Immunologic memory is the hallmark of adaptive immunity.

Immunologic memory enables the host to mount a more rapid and efficient immune response upon subsequent exposure to the antigen.

Choice A is incorrect because rapid recruitment of immune cells to sites of infection and inflammation is a characteristic of innate immunity.

Choice B is incorrect because antigen-independent defense mechanisms are characteristic of innate immunity.

Choice D is incorrect because non-specific host-defense mechanisms are characteristic of innate immunity.

Atomic mass is very close to mass number but with some deviation in the decimal places.

Atomic mass is also known as atomic weight and is the weighted average mass of an atom of an element based on the relative natural abundance of that element’s isotopes.

The mass number, on the other hand, is a count of the total number of protons and neutrons in an atom’s nucleus.

Choice A is incorrect because atomic mass and mass number do not mean the same thing.

Choice B is incorrect because atomic mass is not always greater than mass number.

Choice C is incorrect because atomic mass and mass number are related.

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.

Formation of carboxyhemoglobin.

Carbon monoxide binds to the hemoglobin to create a molecule called carboxyhemoglobin (COHb), which interferes with the body’s ability to transport and use oxygen, especially in the brain.

Choice A is incorrect because carbon monoxide poisoning occurs when carbon monoxide builds up in your bloodstream.

Choice C is incorrect because carbon monoxide poisoning does not increase the production of red blood cells.

Choice D is incorrect because decreased pulmonary function is not a potential complication of carbon monoxide poisoning.

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.

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.

The correct answer is choice B.

A patient with chronic kidney disease is at risk for developing an increase in the concentration of potassium in the blood.

The kidneys play a pivotal role in the regulation of electrolyte balance.

With progressive loss of kidney function, derangements in electrolytes inevitably occur and contribute to poor patient outcomes123.

Choice A is incorrect because calcium concentration is not regulated in the glomerulus.

Choice C is incorrect because chronic kidney disease can result in either an increase or decrease in sodium concentration in the blood.

Choice D is incorrect because chronic kidney disease does not necessarily result in an increase in magnesium concentration in the blood.