Nursing Elites

1. Which type of cell has a nucleus but lacks membrane-bound organelles?

• A. Plant cell
• B. Prokaryotic cell
• C. Animal cell
• D. Fungal cell

Correct answer: B

Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus that is not enclosed within a membrane (nuclear envelope) and lacking membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant, animal, and fungal cells are eukaryotic cells, which have a true nucleus enclosed within a nuclear envelope and contain membrane-bound organelles. Therefore, options A, C, and D are incorrect as they all represent eukaryotic cells that possess membrane-bound organelles.

2. Which structure, located between the pons and the spinal cord, plays a crucial role in coordinating movements, maintaining balance, and posture?

• A. Thalamus
• B. Medulla oblongata
• C. Cerebellum
• D. Hypothalamus

Correct answer: C

Rationale: The correct answer is the cerebellum. The cerebellum, located between the pons and the spinal cord, is responsible for coordinating movements, maintaining balance, and posture. The thalamus functions in relaying sensory and motor signals to the cerebral cortex, the medulla oblongata controls vital autonomic functions such as breathing and heart rate, and the hypothalamus regulates various bodily functions like temperature and hunger. Therefore, the cerebellum is the structure that specifically handles coordination, balance, and posture.

3. With which genotype would the recessive phenotype appear if the dominant allele is marked with 'A' and the recessive allele is marked with 'a'?

• A. AA
• B. aa
• C. Aa
• D. aA

Correct answer: B

Rationale: The recessive phenotype appears when an individual has two copies of the recessive allele. In this case, the recessive allele is marked with 'a.' Therefore, the genotype 'aa' would display the recessive phenotype as both alleles are recessive. Choice A (AA) has two dominant alleles, choice C (Aa) has one dominant and one recessive allele, and choice D (aA) represents the same genotype as Aa due to the principle of allele dominance.

4. Which of the following structures in the respiratory system is responsible for gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchi
• D. Diaphragm

Correct answer: B

Rationale: The correct answer is B: Alveoli. The alveoli in the lungs are responsible for gas exchange. They have a thin membrane that allows for the exchange of oxygen and carbon dioxide between the air in the lungs and the blood in the capillaries surrounding them. This process is essential for respiration, providing oxygen to the body's tissues and removing carbon dioxide, a waste product of cellular metabolism. Choices A, C, and D are incorrect. The trachea is a passageway that carries air to and from the lungs but is not directly involved in gas exchange. Bronchi are airway passages that further divide into smaller bronchioles leading to the alveoli but do not perform gas exchange themselves. The diaphragm is a muscle involved in the breathing process by aiding in inhalation and exhalation, but it is not the structure responsible for gas exchange in the respiratory system.

5. Which macromolecule serves as the repository of genetic information in all living organisms?

• A. Ribonucleic acid (RNA)
• B. Deoxyribonucleic acid (DNA)
• C. Protein
• D. Carbohydrate

Correct answer: B

Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. - RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information. - Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information. - Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.

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