Nursing Elites

1. Which of the following statements accurately characterizes the relationship between genes and chromosomes?

• A. Each gene contains multiple chromosomes.
• B. Each chromosome contains multiple genes.
• C. Genes and chromosomes are two different things referring to the same entity.
• D. Genes and chromosomes are not interchangeable terms and do not always occur in equal numbers.

Correct answer: B

Rationale: The correct answer is B: Each chromosome contains multiple genes. Genes, which are segments of DNA, are located on chromosomes and carry hereditary information. Chromosomes contain many genes, indicating that genes are part of the structure of chromosomes. Choice A is incorrect because genes do not contain chromosomes; rather, they are located on chromosomes. Choice C is incorrect as genes and chromosomes are distinct entities with different functions. Choice D is incorrect because genes and chromosomes are related but not in equal numbers; chromosomes contain multiple genes, but the number of genes can vary between chromosomes.

2. Which division of the autonomic nervous system is responsible for the 'rest and digest' response, promoting relaxation and conservation of energy?

• A. Sympathetic nervous system
• B. Parasympathetic nervous system
• C. Somatic nervous system
• D. Central nervous system

Correct answer: B

Rationale: The correct answer is B: Parasympathetic nervous system. The parasympathetic nervous system is responsible for the 'rest and digest' response, promoting relaxation, conserving energy, and facilitating activities like digestion and lowering heart rate. The sympathetic nervous system, which is not the correct answer, triggers the 'fight or flight' response, preparing the body for stressful situations by increasing heart rate, dilating airways, and releasing adrenaline. The somatic nervous system (choice C) controls voluntary movements, not the autonomic functions related to 'rest and digest.' The central nervous system (choice D) includes the brain and spinal cord and is not specifically involved in the autonomic regulation of bodily functions like the 'rest and digest' response.

3. Which structure of the endocrine system is responsible for maturing T cells?

• A. Hypothalamus
• B. Pineal
• C. Thymus
• D. Thyroid

Correct answer: C

Rationale: The thymus is the primary gland responsible for the maturation of T cells in the immune system. T cells are a type of white blood cell involved in the immune response. The hypothalamus is primarily involved in hormone regulation and maintaining homeostasis. The pineal gland is responsible for secreting melatonin and regulating the sleep-wake cycle. The thyroid gland plays a key role in metabolism regulation through the production of thyroid hormones. Therefore, the correct answer is the thymus because it is specifically associated with the maturation of T cells, making it essential for proper immune function.

4. What term refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction?

• A. Sarcomere
• B. Synapse
• C. Tendon
• D. Myofibril

Correct answer: B

Rationale: The correct answer is B, 'Synapse.' The synapse is the specific term that refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction. At the synapse, neurotransmitters are released by the motor neuron, triggering the muscle fiber to contract. Choice A, 'Sarcomere,' is incorrect as a sarcomere is the basic unit of muscle contraction, not the point of contact between a motor neuron and a muscle fiber. Choice C, 'Tendon,' is incorrect as tendons are fibrous connective tissues that connect muscle to bone, not involved in neuronal communication. Choice D, 'Myofibril,' is incorrect as a myofibril is a structure within muscle fibers where muscle contractions occur, not the specific point of contact for communication between a motor neuron and a muscle fiber.

5. Which cells myelinate neurons in the PNS?

• A. Oligodendrocytes
• B. Astrocytes
• C. Schwann cells
• D. Microglia

Correct answer: C

Rationale: Schwann cells are the glial cells responsible for myelinating neurons in the peripheral nervous system (PNS). They form the myelin sheath around axons, which helps in the conduction of electrical impulses. Oligodendrocytes, on the other hand, myelinate neurons in the central nervous system (CNS). Astrocytes primarily provide support for neuronal function by regulating the chemical environment around neurons and maintaining the blood-brain barrier. Microglia are part of the immune response in the CNS, where they act as the resident macrophages, playing a role in immune surveillance and response to injury or disease. Therefore, the correct answer is Schwann cells (Choice C) as they specifically myelinate neurons in the PNS, differentiating them from the other cell types mentioned in the choices.

Similar Questions