Nursing Elites

1. The chemical equation below is unbalanced. When it is properly balanced, how many molecules of carbon dioxide (CO2) are produced for each molecule of propane (C3H8) in the reaction? 3C3H8 + 5O2 → 3CO2 + 4H2O

• A. One Half.
• B. Two.
• C. Three.
• D. Five.

Correct answer: B

Rationale: The balanced chemical equation for the combustion of propane is: 3C3H8 + 5O2 → 3CO2 + 4H2O. This equation shows that for every 3 molecules of propane (C3H8) consumed, 3 molecules of carbon dioxide (CO2) are produced. Therefore, when properly balanced, 3CO2 are produced for each molecule of propane used. Thus, the correct answer is B: Two. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as determined by the balanced equation.

2. Where does the maturation of T-cells and the production of T-cell receptors occur?

• A. Thymus
• B. Spleen
• C. Lymph nodes
• D. Bone marrow

Correct answer: A

Rationale: The correct answer is the Thymus. T-cells mature and develop their receptors in the thymus gland, making it a vital organ for the immune system. The thymus provides the necessary environment for T-cells to differentiate and acquire their specific receptors and functions, which are essential for their role in the adaptive immune response. The spleen, lymph nodes, and bone marrow are all important components of the immune system, but they do not primarily serve as sites for T-cell maturation and T-cell receptor production.

3. What information does a genotype provide that a phenotype does not?

• A. The genotype necessarily includes the proteins coded for by its alleles.
• B. The genotype will always display an organism's recessive alleles.
• C. The genotype must include the organism's physical characteristics.
• D. The genotype indicates what an organism's parents looked like.

Correct answer: A

Rationale: The genotype provides information about the specific genetic makeup of an organism, including the alleles it possesses for a particular trait. This information is not always directly reflected in the phenotype, which is the observable physical characteristics of an organism. The genotype determines the proteins coded for by its alleles, but the phenotype is the expression of those proteins in the organism's traits. Therefore, the genotype necessarily includes the proteins coded for by its alleles, a detail not provided solely by the phenotype.\nChoice B is incorrect because the genotype may include dominant alleles as well, not just recessive ones. Choice C is incorrect because the genotype refers to genetic information, not physical characteristics. Choice D is incorrect because the genotype does not directly indicate what an organism's parents looked like; it primarily describes the genetic information inherited from parents.

4. What is the process of breaking down and rebuilding bone tissue called?

• A. Ossification
• B. Remodeling
• C. Calcification
• D. Osteoporosis

Correct answer: B

Rationale: The correct answer is 'Remodeling.' Remodeling is the process of breaking down and rebuilding bone tissue. Ossification is the process of bone formation, not breaking down and rebuilding bone tissue. Calcification involves the deposition of calcium salts in tissues, but it is not specifically related to breaking down and rebuilding bone tissue. Osteoporosis is a condition characterized by decreased bone density leading to increased bone fragility, not the process of breaking down and rebuilding bone tissue.

5. Where are most of the body's immune cells located?

• A. Blood
• B. Brain
• C. Skin
• D. Large intestine

Correct answer: A

Rationale: - The majority of the body's immune cells are located in the blood. Immune cells, such as white blood cells (leukocytes), circulate throughout the body via the bloodstream to detect and fight off infections and foreign invaders. - While immune cells are also present in other parts of the body like the lymph nodes, spleen, and bone marrow, the blood serves as a primary conduit for immune cells to travel to different tissues and organs to carry out their functions. - The brain (option B) is protected by the blood-brain barrier, which limits the entry of immune cells into the brain to prevent inflammation and damage. - The skin (option C) contains immune cells like Langerhans cells that help protect against pathogens, but the largest concentration of immune cells is found in the blood. - The large intestine (option D) also houses a significant amount of immune cells due to its role in interacting with the external environment through the gut-associated lymphoid tissue, but the primary location for most of the body's immune cells is the blood.

Similar Questions