Nursing Elites

1. What is the structure that attaches to each chromosome during mitosis?

• A. Centromere
• B. Telomere
• C. Spindle apparatus
• D. Nucleolus

Correct answer: A

Rationale: The correct answer is the centromere. It is the structure that attaches to each chromosome during mitosis. The centromere serves as the attachment point for spindle fibers during cell division, ensuring proper distribution of chromosomes to daughter cells. Telomeres are found at the ends of chromosomes, providing protection and stability. The spindle apparatus is responsible for separating chromosomes during cell division. The nucleolus, located within the nucleus, is involved in ribosomal RNA synthesis and not in chromosome attachment during mitosis.

2. What is the scientific term for the involuntary rhythmic contraction and relaxation of the heart muscle?

• A. Peristalsis
• B. Myogenesis
• C. Myocardial contractility
• D. Systole and diastole

Correct answer: D

Rationale: The correct answer is D: Systole and diastole. Systole and diastole are the two phases of the cardiac cycle where the heart muscle contracts (systole) and relaxes (diastole) rhythmically to pump blood throughout the body. This rhythmic process ensures proper blood circulation by pumping blood to the lungs and the rest of the body. Peristalsis, on the other hand, refers to the involuntary constriction and relaxation of the muscles in the gastrointestinal tract, aiding in the movement of food and waste. Myogenesis is the process of muscle tissue formation, and myocardial contractility pertains to the heart muscle's ability to contract efficiently.

3. During embryonic development, all tissues originate from

• A. Epithelial tissue only
• B. Muscle tissue only
• C. Connective tissue only
• D. Embryonic germ layers

Correct answer: D

Rationale: During embryonic development, all tissues originate from the three primary germ layers: ectoderm, mesoderm, and endoderm. These germ layers give rise to various tissues and organs in the developing embryo through a process called gastrulation. Epithelial, muscle, and connective tissues are derived from these germ layers during development. Therefore, choices A, B, and C are incorrect as tissues do not originate from a single type of tissue but rather from the embryonic germ layers which differentiate into various tissues and organs.

4. What is the primary function of the atrioventricular (AV) node within the heart?

• A. Generate the electrical impulse for contraction (pacemaker function)
• B. Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction.
• C. Increase blood pressure within the ventricles during systole.
• D. Separate oxygenated and deoxygenated blood flow in the heart.

Correct answer: B

Rationale: The correct answer is B: Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction. The primary function of the atrioventricular (AV) node is to coordinate the transmission of electrical signals between the atria and the ventricles. It ensures proper timing between atrial and ventricular contractions, allowing for efficient blood pumping through the heart. Choice A is incorrect because the AV node does not generate the initial electrical impulse; that role is typically attributed to the sinoatrial (SA) node. Choice C is incorrect as the AV node does not directly influence blood pressure within the ventricles. Choice D is also incorrect as the separation of oxygenated and deoxygenated blood is primarily achieved by the anatomical structure of the heart (e.g., atria and ventricles) and not the AV node.

5. Which type of carbohydrate is the main component of the cell wall in plant cells?

• A. Starch
• B. Glucose
• C. Cellulose
• D. Chitin

Correct answer: C

Rationale: The correct answer is 'Cellulose.' Cellulose is the main component of the cell wall in plant cells, providing structural support and rigidity. Starch, while a carbohydrate, is a storage form of glucose in plants and not a component of the cell wall. Glucose is a simple sugar that can be used as an energy source but is not the main component of the cell wall. Chitin is a structural carbohydrate found in the exoskeleton of arthropods and fungi, not in plant cell walls.

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