what is the role of rna in the regulation of gene expression

ATI TEAS 7

TEAS Test 7 science

1. What is the role of RNA in the regulation of gene expression?

A. Provides energy for the process
B. Controls the timing and location of protein synthesis
C. Translates the genetic code into amino acids
D. Stores genetic information

Correct answer: B

Rationale: A) RNA does not provide energy for the process of gene expression. Energy is typically provided by molecules like ATP. B) RNA plays a crucial role in controlling the timing and location of protein synthesis through processes like transcriptional regulation, RNA splicing, and post-transcriptional modifications. It helps determine when and where specific proteins are produced in the cell. C) While mRNA translates the genetic code into amino acids during the process of translation, this is not the primary role of RNA in the regulation of gene expression. D) RNA does not store genetic information in the same way that DNA does. DNA is the molecule responsible for storing genetic information in the form of genes. Therefore, option B is the most appropriate choice as it accurately describes the role of RNA in regulating gene expression.

2. Which of the following neurotransmitters slows down the activity of neurons, preventing them from becoming overexcited?

A. Acetylcholine
B. Dopamine
C. GABA
D. Serotonin

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA acts as an inhibitory neurotransmitter that reduces neuronal activity, thus preventing overexcitation. Acetylcholine (choice A) is involved in muscle control and cognitive function, but it is not primarily responsible for slowing down neuronal activity. Dopamine (choice B) plays a role in reward-motivated behavior and motor control, rather than inhibiting neuronal firing. Serotonin (choice D) is involved in mood regulation, sleep, and appetite but does not primarily slow down neuronal activity to prevent overexcitation.

3. What is the term for the process of a gas changing directly into a solid?

A. Condensation
B. Deposition
C. Sublimation
D. Evaporation

Correct answer: B

Rationale: The correct term for the process of a gas changing directly into a solid is deposition. During deposition, gas particles lose energy and transition directly into the solid state without passing through the liquid phase. Sublimation, on the other hand, is the process in which a solid changes directly into a gas without going through the liquid phase. Condensation is the process where gas changes into a liquid state. Evaporation, on the contrary, is the conversion of a liquid to a gas. Therefore, the correct answer is B, deposition.

4. Balance the following redox reaction in acidic solution: I⁻ (aq) + Cr₂O₇²⁻ (aq) -> I₂ (aq) + Cr³⁺ (aq). Identify the oxidizing agent and reducing agent.

A. I⁻ is oxidized, Cr₂O₇²⁻ is reduced
B. I⁻ is reduced, Cr₂O₇²⁻ is oxidized
C. Both I⁻ and Cr₂O₇²⁻ are oxidized
D. Both I⁻ and Cr₂O₇²⁻ are reduced

Correct answer: B

Rationale: In the given redox reaction, I⁻ is gaining electrons to form I₂, which means I⁻ is being reduced (undergoing reduction). On the other hand, Cr₂O₇²⁻ is losing electrons to form Cr³⁺, indicating that Cr₂O₇²⁻ is being oxidized (undergoing oxidation). Therefore, I⁻ is the reducing agent and Cr₂O₇²⁻ is the oxidizing agent. Choice A is incorrect because I⁻ is being reduced, not oxidized. Choice C is incorrect as both species cannot be oxidized in the same reaction. Choice D is incorrect as both species cannot be reduced in the same reaction.

5. What is the function of the Vas Deferens?

A. Produces fluid to increase sperm mobility
B. Site where the egg matures
C. Helps control urine flow
D. Connects each testis to the urethra

Correct answer: D

Rationale: The vas deferens is a duct that connects each testis to the urethra, allowing the transport of sperm. Choice A is incorrect because the vas deferens does not produce fluid to increase sperm mobility. Choice B is incorrect as the vas deferens is not a site for egg maturation. Choice C is incorrect as the vas deferens does not help control urine flow, its primary role is in the transport of sperm.