Nursing Elites

1. Which white blood cell type is responsible for the initial attack on pathogens?

• A. Red blood cells
• B. Platelets
• C. Phagocytes
• D. Lymphocytes

Correct answer: C

Rationale: Phagocytes are a type of white blood cell that is crucial in the initial attack on pathogens. These cells have the ability to engulf and digest foreign particles such as bacteria and viruses, thereby preventing infections. Red blood cells primarily function in oxygen transport, platelets are vital for blood clotting, and lymphocytes are involved in the immune response. However, phagocytes are specifically designed to provide the initial defense against pathogens by directly attacking and eliminating them.

2. Which statement is true regarding the process of digestion?

• A. Digestion of starch begins in the mouth.
• B. Amylase is produced by the stomach to help break down food in the upper intestine.
• C. The di- and tri-saccharides produced in early digestion are absorbed through the intestinal wall.
• D. Proteases are responsible for breaking down starches.

Correct answer: A

Rationale: The statement 'Digestion of starch begins in the mouth' is correct. Salivary amylase, an enzyme produced in the salivary glands, initiates the breakdown of starch into simpler sugars like maltose in the mouth before further digestion in the stomach. This initial breakdown of starch is crucial in the digestion of carbohydrates, marking the beginning of the digestive process. Choice B is incorrect because amylase is produced in the salivary glands, not the stomach. Choice C is incorrect because di- and tri-saccharides are further broken down into monosaccharides before absorption. Choice D is incorrect because proteases are enzymes that break down proteins, not starches.

3. Which of the following glands is NOT directly controlled by the pituitary gland?

• A. Thyroid gland
• B. Adrenal glands
• C. Pancreas (Islets of Langerhans)
• D. Parathyroid glands

Correct answer: C

Rationale: The pituitary gland, known as the master gland, regulates various endocrine glands by releasing specific hormones. The thyroid gland, adrenal glands, and parathyroid glands are directly controlled by the pituitary gland through hormones like thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), and parathyroid hormone (PTH) respectively. However, the pancreas, particularly the Islets of Langerhans, is not directly influenced by the pituitary gland. The pancreas is mainly governed by blood glucose levels and hormones such as insulin and glucagon, which play a crucial role in regulating blood sugar levels and metabolism. Therefore, the correct answer is C. Choice A, the thyroid gland, is controlled by the pituitary gland through TSH. Choice B, the adrenal glands, are regulated by the pituitary gland via ACTH. Choice D, the parathyroid glands, are under the direct control of the pituitary gland through PTH.

4. Which property of a wave remains constant when it crosses a boundary between two different media?

• A. Frequency
• B. Wavelength
• C. Amplitude
• D. Speed

Correct answer: D

Rationale: When a wave crosses a boundary between two different media, its speed is the property that remains constant. This is due to the principle of conservation of energy. While the frequency and wavelength of a wave may change as it moves from one medium to another, the speed of the wave remains constant. This phenomenon is a result of the wave adjusting its frequency and wavelength to maintain a consistent speed in different media. Therefore, choices A, B, and C are incorrect. Frequency and wavelength may change when a wave moves across media, and amplitude may also be affected by the medium, but the speed of the wave will remain constant.

5. In meiosis, how many divisions occur, and how many daughter cells are produced?

• A. One division, two daughter cells
• B. Two divisions, four daughter cells
• C. Four divisions, eight daughter cells
• D. Eight divisions, sixteen daughter cells

Correct answer: B

Rationale: In meiosis, there are two divisions: meiosis I and meiosis II. During meiosis I, homologous chromosomes separate, resulting in two daughter cells with half the number of chromosomes as the parent cell. In meiosis II, sister chromatids separate, resulting in a total of four daughter cells, each with a haploid set of chromosomes. Therefore, meiosis involves two divisions and produces four daughter cells. Choice A is incorrect because meiosis involves two divisions, not one. Choice C and D are incorrect as meiosis does not go through four or eight divisions, resulting in eight or sixteen daughter cells.

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