Nursing Elites

1. What is the role of DNA in evolution?

• A. It stores genetic information that can be passed on to offspring
• B. It allows for mutations that can introduce new variations
• C. It regulates the expression of genes that influence traits
• D. All of the above

Correct answer: D

Rationale: Rationale: A) DNA stores genetic information that is passed on from parents to offspring through the process of reproduction. This genetic information contains instructions for the development and functioning of an organism. B) DNA can undergo mutations, which are changes in the genetic sequence. These mutations can introduce new variations in the DNA, leading to genetic diversity within a population. C) DNA plays a crucial role in regulating the expression of genes. Gene expression determines which proteins are produced in an organism, influencing its traits and characteristics. D) Therefore, DNA is involved in all of the above processes, making it a key factor in evolution by driving genetic variation, inheritance, and gene expression.

2. Which macromolecule serves as the repository of genetic information in all living organisms?

• A. Ribonucleic acid (RNA)
• B. Deoxyribonucleic acid (DNA)
• C. Protein
• D. Carbohydrate

Correct answer: B

Rationale: Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. - RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information. - Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information. - Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.

3. The Gram stain is a differential staining technique used to classify bacteria based on their cell wall composition. Gram-positive bacteria appear

• A. Pink
• B. Blue
• C. Red
• D. Purple

Correct answer: D

Rationale: Rationale: The Gram stain is a differential staining technique that divides bacteria into two groups based on their cell wall composition: Gram-positive and Gram-negative. Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which retains the crystal violet stain used in the Gram staining procedure. As a result, Gram-positive bacteria appear purple under the microscope after staining. In contrast, Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane that can be penetrated by the counterstain safranin, causing them to appear pink or red. Blue is not typically used to describe the color of bacteria in a Gram stain.

4. What is the difference between mitosis and meiosis?

• A. Mitosis produces haploid cells, while meiosis produces diploid cells
• B. Mitosis involves crossing over, while meiosis does not.
• C. Mitosis results in four daughter cells, while meiosis results in two
• D. Mitosis is responsible for sexual reproduction, while meiosis is responsible for asexual reproduction.

Correct answer: C

Rationale: Rationale: - Mitosis is a type of cell division that results in two identical daughter cells with the same number of chromosomes as the parent cell. Therefore, mitosis results in two daughter cells. - Meiosis is a type of cell division that results in four daughter cells, each with half the number of chromosomes as the parent cell. This reduction in chromosome number is essential for sexual reproduction. - Option A is incorrect because mitosis produces diploid cells (cells with the same number of chromosomes as the parent cell), while meiosis produces haploid cells (cells with half the number of chromosomes as the parent cell). - Option B is incorrect because crossing over, the exchange of genetic material between homologous chromosomes, occurs during meiosis and not during mitosis. - Option D is incorrect because mitosis is not responsible for sexual reproduction; it is a process of asexual reproduction and

5. What is the milky-white fluid transported by the lymphatic vessels called?

• A. Plasma
• B. Blood
• C. Chyle
• D. Mucus

Correct answer: C

Rationale: The milky-white fluid transported by the lymphatic vessels is called 'Chyle.' Chyle is formed in the small intestine during the absorption of fats. It primarily consists of lymph and emulsified fats. Plasma refers to the liquid component of blood, while blood carries red blood cells, white blood cells, platelets, and plasma. Mucus is a slimy substance produced by mucous membranes. Therefore, option C, 'Chyle,' is the correct answer in this context.

6. What is the function of the epiglottis?

• A. Produces saliva
• B. Senses taste
• C. Prevents food from entering the windpipe
• D. Filters blood

Correct answer: C

Rationale: Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the windpipe (trachea) during swallowing to prevent food and liquids from entering the airway. This action ensures that food and liquids are directed to the esophagus and down into the stomach, rather than entering the respiratory system, which could lead to choking or aspiration pneumonia. The other options (A) Produces saliva, (B) Senses taste, and (D) Filters blood are functions of other structures in the body and are not related to the role of the epiglottis.

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