Which factor is primarily responsible for the movement of water across cell membranes in osmosis?

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”.

The correct answer is choice B.

Maintaining normal body temperature and blood pressure.

Early identification and management of potential organ donors must take into consideration specific pathophysiologic changes for medical optimization 1.

The VIPPS (ventilation, infusion and pumping, pharmacological treatment, and specificities) strategy is a mnemonic method that brings together key aspects of the restoration of oxygen delivery to tissues during hemodynamic instability plus organ optimization strategies.

Choice A is incorrect because administering antibiotics to prevent infection is not the most important intervention to preserve organ viability.

Choice C is incorrect because providing emotional support to family members, while important, is not an intervention that directly affects organ viability.

Choice D is incorrect because applying eye drops and ointment to prevent corneal drying is not the most important intervention to preserve organ viability.

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.

The correct answer is choice C. Substitution.

A substitution mutation is a type of point mutation where one base in the DNA sequence is replaced by another base.

Choice A is incorrect because a deletion mutation occurs when one or more bases are removed from the DNA sequence.

Choice B is incorrect because an insertion mutation occurs when one or more bases are added to the DNA sequence.

Choice D is incorrect because an inversion mutation occurs when a segment of DNA is reversed within the chromosome.

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.

Proximal tubule

The proximal tubule is responsible for reabsorbing all the nutrients and most of the water.

Choice A is incorrect because the distal tubule is not primarily responsible for reabsorbing ions, water and nutrients.

Choice C is incorrect because the glomerulus is responsible for filtering fluid and solutes out of the blood to form a glomerular filtrate.

Choice D is incorrect because the Loop of Henle is not primarily responsible for reabsorbing ions, water and nutrients.

The correct answer is choice A.

Increased respiration rate to remove excess CO2.

The body regulates blood pH through several mechanisms, including chemical buffers, the respiratory system, and the urinary system.

The respiratory system can adjust blood pH by changing the rate of respiration to remove or retain CO2.

When there is excess acid in the blood, the respiratory rate increases to remove more CO2, which helps to raise blood pH.

Choice B is incorrect because decreasing the respiration rate would retain CO2, which would lower blood pH.

Choice C is incorrect because increased water intake would not directly affect blood pH levels.

Choice D is incorrect because decreased water intake would not directly affect blood pH levels.

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.

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.

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.