Nursing Elites

1. When referring to blood vessel walls, the term 'atherosclerosis' describes:

• A. The abnormal buildup of plaque within the arterial walls.
• B. The inflammation of the inner lining of blood vessels.
• C. The dilation and weakening of a blood vessel wall (aneurysm).
• D. The normal process of blood vessel wall thickening with age.

Correct answer: A

Rationale: The correct answer is A: 'The abnormal buildup of plaque within the arterial walls.' Atherosclerosis is the process where plaque, consisting of fat, cholesterol, calcium, and other substances, accumulates within the arteries. This buildup can lead to the hardening and narrowing of arteries, reducing blood flow and potentially causing severe health issues like heart attacks and strokes. Choice B is incorrect because inflammation of the inner lining of blood vessels is known as vasculitis, not atherosclerosis. Choice C is incorrect as it describes an aneurysm, which is a dilation and weakening of a blood vessel wall, not atherosclerosis. Choice D is incorrect as it describes arteriosclerosis, a process of blood vessel wall thickening with age, which is different from atherosclerosis.

2. Which blood type is considered a universal donor?

• A. A
• B. B
• C. AB
• D. O

Correct answer: D

Rationale: Blood type O is considered the universal donor because individuals with type O blood can donate red blood cells to individuals with any ABO blood type (A, B, AB, or O) without causing an adverse reaction. Type O blood lacks A or B antigens on the surface of red blood cells, minimizing the risk of an immune response when transfused into individuals with different blood types. Therefore, type O blood is in high demand for blood transfusions in emergency situations when the recipient's blood type is unknown or when there is a shortage of specific blood types. Choices A, B, and AB are not considered universal donors. Individuals with blood types A, B, or AB can only donate to individuals with compatible blood types to avoid adverse reactions since they have A and/or B antigens on the surface of their red blood cells, making them incompatible with all blood types.

3. How can bacteria acquire new genetic material from their environment?

• A. Transformation
• B. Transduction
• C. Conjugation
• D. All of the above

Correct answer: D

Rationale: A) Transformation: Transformation is the process by which bacteria can take up free DNA from their environment and incorporate it into their own genome, leading to the acquisition of new genetic material and traits. B) Transduction: Transduction involves the transfer of genetic material from one bacterium to another by a bacteriophage, a virus that infects bacteria. The bacteriophage carries bacterial DNA from one host cell to another, facilitating the transfer of genetic material. C) Conjugation: Conjugation is a mechanism of horizontal gene transfer in bacteria where genetic material is transferred between two bacterial cells in direct contact. This transfer is facilitated by a conjugative plasmid carrying the genetic information. Therefore, all the processes mentioned (transformation, transduction, and conjugation) are ways in which bacteria can acquire new genetic material from their environment.

4. Which of the following is the primary physical barrier the body uses to prevent infection?

• A. mucus membranes
• B. stomach acid
• C. skin
• D. urine

Correct answer: C

Rationale: The correct answer is 'C: skin.' The skin is the primary physical barrier the body uses to prevent infection. It acts as a protective shield that prevents harmful microorganisms from entering the body. The outer layer of the skin, known as the epidermis, acts as a tough physical barrier that blocks the entry of pathogens. Additionally, the skin has special immune cells that can help fight off invaders that manage to breach the physical barrier. Choices A, B, and D are incorrect. While mucous membranes, stomach acid, and urine play important roles in the body's defense against pathogens, the primary physical barrier is the skin, which covers the entire body and provides a robust protective barrier.

5. What is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division?

• A. Centromere
• B. Chromatid
• C. Chromosome
• D. Gene

Correct answer: C

Rationale: A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division. It contains the genetic material and is essential for cell division and replication. The centromere is a specific region of a chromosome that plays a role in cell division. A chromatid is one half of a duplicated chromosome, and a gene is a unit of heredity responsible for specific traits. Therefore, the correct answer is 'Chromosome' as it represents the entire condensed DNA molecule during cell division.

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