The liver combines a toxic by-product of amino acid metabolism, ammonia, with another waste product, carbon dioxide, to form the water-soluble ______, which is excreted in the kidneys.

Correct Answer: C

Rationale: Rationale: The correct answer is C: urea. Ammonia is toxic and needs to be converted into a less toxic form for excretion. The liver combines ammonia with carbon dioxide to form urea through the urea cycle. Urea is water-soluble and is excreted by the kidneys in urine. Cholesterol (A) is a lipid molecule, bilirubin (B) is a by-product of heme metabolism, and uric acid (D) is a by-product of purine metabolism. These molecules are not formed from the combination of ammonia and carbon dioxide and are not excreted in the kidneys.

Correct Answer: D

Rationale: The correct answer is D because the presence of folds, villi, and microvilli on the surface of enterocytes significantly increases the absorptive area of the intestine. The folds increase the surface area, villi further increase the surface area, and microvilli further amplify the absorptive surface. This intricate structure allows for efficient absorption of nutrients. Option A is incorrect as the absorptive area is not equivalent to a tennis court. Option B is incorrect because not all options are correct. Option C is incorrect because changes in motility can affect nutrient absorption but do not directly relate to the absorptive area of the intestine like the structural features mentioned in option D.

Correct Answer: B

Rationale: Rationale: Choice B is correct because GABA is indeed released by GABA neurons and acts to inhibit the propagation of signals triggered by dopamine in the post-synaptic neuron. GABA functions as an inhibitory neurotransmitter in the central nervous system. Choices A and C are incorrect. Choice A is inaccurate because GABA inhibits the release of dopamine, not the other way around. Choice C is incorrect as heroin and morphine act on opioid receptors, not GABA receptors. Choice D is incorrect because not all statements are true.

Correct Answer: B

Rationale: The correct answer is B because SNPs are actually a common source of genetic polymorphisms, occurring frequently in the human genome. SNPs are variations in a single nucleotide base and are estimated to occur once every 300 nucleotides. Choice A is incorrect because of this high frequency. Choice C is also incorrect as certain SNPs can indeed impact gene expression and health outcomes. Choice D is incorrect because B is not true, making the statement false. In summary, B is the correct answer as SNPs are not rare but rather common genetic variations in humans.

Correct Answer: C

Rationale: The correct answer is C because LPN/LVNs can assist in planning bathing, turning, and ambulation for a morbidly obese client. This is crucial in preventing complications such as pressure ulcers, deep vein thrombosis, and respiratory issues. LPN/LVNs can provide physical support and guidance to ensure the client's safety and comfort during these activities. Choice A is incorrect because obtaining oversized equipment is not the primary role of LPN/LVNs. Choice B is also incorrect as setting up a reinforced trapeze bar is more of a facility management task. Choice D is incorrect as designing alternatives for routine tasks is not within the scope of practice for LPN/LVNs.