Nursing Elites

1. The chemical equation below is unbalanced. When it is properly balanced, how many molecules of carbon dioxide (CO2) are produced for each molecule of propane (C3H8) in the reaction? 3C3H8 + 5O2 → 3CO2 + 4H2O

• A. One Half.
• B. Two.
• C. Three.
• D. Five.

Correct answer: B

Rationale: The balanced chemical equation for the combustion of propane is: 3C3H8 + 5O2 → 3CO2 + 4H2O. This equation shows that for every 3 molecules of propane (C3H8) consumed, 3 molecules of carbon dioxide (CO2) are produced. Therefore, when properly balanced, 3CO2 are produced for each molecule of propane used. Thus, the correct answer is B: Two. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as determined by the balanced equation.

2. Which type of mutation involves a change in the number of chromosomes?

• A. Point mutation
• B. Frameshift mutation
• C. Missense mutation
• D. Aneuploidy

Correct answer: D

Rationale: A) Point mutation involves a change in a single nucleotide base pair within the DNA sequence. B) Frameshift mutation involves the insertion or deletion of nucleotides, causing a shift in the reading frame of the genetic code. C) Missense mutation involves a single nucleotide change that results in a codon that codes for a different amino acid. D) Aneuploidy involves a change in the number of chromosomes, where an individual may have an extra chromosome (trisomy) or a missing chromosome (monosomy). Aneuploidy can lead to genetic disorders such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X). Changing the number of chromosomes is a characteristic feature of aneuploidy, making it the correct answer. Point mutation, frameshift mutation, and missense mutation do not involve a change in the number of chromosomes and are focused on alterations at the nucleotide level within the DNA sequence.

3. What is the primary function of red blood cells in the cardiovascular system?

• A. To transport oxygen throughout the body.
• B. To fight infection and disease.
• C. To help regulate blood clotting.
• D. To remove waste products from the body.

Correct answer: A

Rationale: Red blood cells, also known as erythrocytes, play a crucial role in the cardiovascular system by primarily transporting oxygen from the lungs to the body's tissues and organs. This essential function is carried out through the interaction of hemoglobin, a protein within red blood cells, which binds to oxygen in the lungs and releases it in the body's tissues. Choices B, C, and D are incorrect. Red blood cells are not actively involved in fighting infections, regulating blood clotting, or eliminating waste products from the body.

4. What is one feature that both prokaryotes and eukaryotes have in common?

• A. A plasma membrane
• B. A nucleus enclosed by a membrane
• C. Organelles
• D. A nucleoid

Correct answer: A

Rationale: The correct answer is A: A plasma membrane. Both prokaryotes and eukaryotes share the characteristic of having a plasma membrane that surrounds the cell. While eukaryotes also possess a nucleus enclosed by a membrane and various organelles, prokaryotes lack a nucleus and membrane-bound organelles. The plasma membrane, however, is a universal feature found in all cells, regardless of their classification as prokaryotic or eukaryotic. Choice B is incorrect because only eukaryotes have a nucleus enclosed by a membrane. Choice C is incorrect because prokaryotes have limited organelles compared to eukaryotes. Choice D is incorrect as a nucleoid is a region in prokaryotic cells where the genetic material is located, not a common feature shared with eukaryotes.

5. Which hormone, produced by the pineal gland, plays a role in regulating sleep-wake cycles and is often associated with the body's internal circadian rhythm?

• A. Melatonin
• B. Serotonin
• C. Dopamine
• D. Endorphin

Correct answer: A

Rationale: Melatonin is the hormone produced by the pineal gland that plays a crucial role in regulating sleep-wake cycles and is associated with the body's internal circadian rhythm. Melatonin levels typically rise in the evening, signaling to the body that it is time to sleep, and decrease in the morning, helping to wake up and feel alert. Serotonin, dopamine, and endorphins are neurotransmitters that serve different functions in the body and are not primarily responsible for regulating sleep-wake cycles. Serotonin is involved in regulating mood, appetite, and sleep. Dopamine plays a role in reward-motivated behavior and motor control. Endorphins are involved in pain regulation and are often referred to as the body's natural painkillers.

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