Nursing Elites

1. Explain how a single gene mutation can lead to multiple phenotypes depending on the organism.

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can affect different biochemical pathways or developmental processes, leading to a cascade of downstream effects and diverse phenotypic consequences.

2. The T wave on an ECG corresponds to:

• A. Atrial depolarization
• B. Ventricular depolarization
• C. Atrial repolarization
• D. Ventricular repolarization

Correct answer: D

Rationale: The T wave on an ECG corresponds to ventricular repolarization. During this phase, the ventricles are resetting electrically after contraction, preparing for the next heartbeat. Atrial depolarization is represented by the P wave, ventricular depolarization by the QRS complex, and atrial repolarization is typically hidden within the QRS complex. Therefore, option D, 'Ventricular repolarization,' is the correct choice when identifying the electrical activity represented by the T wave on an ECG.

3. Parkinson's disease is a neurodegenerative disorder affecting which neurotransmitter?

• A. Dopamine
• B. Acetylcholine
• C. Serotonin
• D. Glutamate

Correct answer: A

Rationale: The correct answer is A: Dopamine. Parkinson's disease is characterized by a progressive loss of dopamine-producing neurons in the brain. Dopamine is a neurotransmitter responsible for transmitting signals in the brain that control movement and coordination. A decrease in dopamine levels leads to the typical motor symptoms of Parkinson's, such as tremors, rigidity, and bradykinesia. Acetylcholine (option B) is involved in muscle movement but is not primarily affected in Parkinson's disease. Serotonin (option C) and glutamate (option D) are neurotransmitters that play different roles in the brain and are not primarily associated with Parkinson's disease. Therefore, the correct neurotransmitter affected in Parkinson's disease is dopamine.

4. Which element is a good conductor of electricity but is not a metal?

• A. Copper
• B. Silver
• C. Graphite
• D. Gold

Correct answer: C

Rationale: While metals are known for their conductivity, some non-metals like graphite also exhibit this property due to their unique electronic structure

5. Which protein complex in the sarcomere is responsible for the thick filament?

• A. Actin
• B. Myosin
• C. Tropomyosin
• D. Troponin

Correct answer: B

Rationale: The correct answer is B: Myosin. In the sarcomere, the thick filament is composed of myosin protein. Myosin is responsible for the interaction with actin filaments during muscle contraction, forming cross-bridges that generate the force required for muscle movement. Actin (choice A) is a component of the thin filament in the sarcomere, while tropomyosin (choice C) and troponin (choice D) are regulatory proteins associated with muscle contraction but are not part of the thick filament. Understanding the specific components of the sarcomere is crucial for comprehending muscle contraction mechanisms.

6. What is the function of introns in eukaryotic genes?

• A. They code for protein sequences.
• B. They are involved in gene regulation.
• C. They are removed during mRNA processing.
• D. They are non-functional remnants of ancient DNA.

Correct answer: C

Rationale: Rationale: A) Introns do not code for protein sequences. Exons are the segments of DNA that code for proteins. B) While introns can indirectly influence gene regulation, their primary function is not directly involved in gene regulation. C) Introns are non-coding regions of DNA that are transcribed into pre-mRNA but are removed during mRNA processing through a process called splicing. This allows only the exons to be included in the mature mRNA that will be translated into proteins. D) While introns were once thought to be non-functional remnants of ancient DNA, research has shown that they can have regulatory functions and play a role in gene expression.

Similar Questions