Nursing Elites

1. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: a

Rationale: The correct answer is A: Calcitonin. Calcitonin is a hormone produced by the thyroid gland that plays a crucial role in regulating calcium levels in the blood. It works by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys. This helps to maintain the proper balance of calcium in the body. Parathyroid hormone (PTH) works in the opposite way, increasing calcium levels in the blood when they are low. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism and growth, not calcium levels. Insulin is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels. Therefore, the correct hormone in this case is Calcitonin.

2. The "master gland" of the endocrine system, located at the base of the brain, secretes various hormones that control other glands is the:

• A. Thyroid gland
• B. Pituitary gland
• C. Adrenal gland
• D. Pancreas

Correct answer: B

Rationale: The correct answer is B: Pituitary gland. The pituitary gland is often referred to as the "master gland" because it plays a crucial role in regulating other endocrine glands in the body. It is located at the base of the brain and secretes various hormones that control functions such as growth, metabolism, reproduction, and stress response. The thyroid gland (A) regulates metabolism, the adrenal gland (C) produces hormones involved in stress response, and the pancreas (D) is primarily responsible for regulating blood sugar levels through insulin production, but they do not serve as the master gland of the endocrine system.

3. What term describes the bending of waves around obstacles or through openings?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Absorption

Correct answer: c

Rationale: Diffraction occurs when waves bend around obstacles or spread after passing through small openings.

4. In meiosis I, how are sister chromatids distinguished from homologous chromosomes?

• A. Sister chromatids share the same centromere, while homologues have different centromeres.
• B. Sister chromatids have identical DNA sequences, while homologues have slightly different sequences due to crossing over.
• C. Sister chromatids repel each other, while homologues attract each other during synapsis.
• D. Sister chromatids separate during anaphase I, while homologues separate during anaphase II.

Correct answer: B

Rationale: While sister chromatids are identical copies of the same chromosome, homologous chromosomes are paired copies, each inherited from one parent. Crossing over during meiosis I can lead to slight differences in their DNA sequences.

5. What is the stoichiometric coefficient of nitrogen (N2) in the balanced equation for the Haber process: N2 + 3H2 → 2NH3?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: a

Rationale: The coefficient of N2 is 1 in the balanced equation

6. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?

• A. Dendrite
• B. Myelin sheath
• C. Synapse
• D. Cell body

Correct answer: b

Rationale: The correct answer is B: Myelin sheath. The myelin sheath is a fatty substance that surrounds the axon of a neuron, acting as an insulator to speed up the transmission of nerve impulses. It does this by creating gaps called nodes of Ranvier where the nerve impulses jump from one node to the next, allowing for faster signal conduction. Dendrites are branch-like extensions that receive signals from other neurons, the synapse is the junction between two neurons where neurotransmitters are released, and the cell body contains the nucleus and organelles of the neuron, but it is the myelin sheath that specifically insulates and speeds up the transmission of nerve impulses along the axon.

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