Nursing Elites

1. Classifications of human tissues exclude:

• A. Epithelial tissue
• B. Nervous tissue
• C. Adipose tissue (a specialized form of connective tissue)
• D. Bony tissue

Correct answer: D

Rationale: The correct answer is D: Bony tissue. Classifications of human tissues typically include epithelial tissue, nervous tissue, and connective tissue types such as adipose tissue. Bony tissue, also known as bone tissue, is a specialized form of connective tissue that provides structural support and protection for the body. Therefore, it is not excluded from classifications of human tissues. Choices A, B, and C are valid types of human tissues and are correctly included in classifications of human tissues.

2. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

3. Which of the following is NOT a tissue layer found in skeletal bone?

• A. periosteum
• B. bone marrow
• C. enamel
• D. cancellous bone

Correct answer: C

Rationale: Enamel is a hard, outer layer that covers the crown of a tooth and is not a tissue layer found in skeletal bone. The other options, periosteum, bone marrow, and cancellous bone, are all tissue layers or components found in skeletal bone. Periosteum is the connective tissue layer covering the bone surface, bone marrow is found within the bone cavities, and cancellous bone is a spongy, porous bone tissue.

4. What type of reaction is represented by the following equation: Fe2O3 (s) + 3H2 (g) -> 2Fe (s) + 3H2O (g)?

• A. Combustion
• B. Decomposition
• C. Single displacement
• D. Redox reaction

Correct answer: C

Rationale: The correct answer is C: Single displacement. This reaction is a single displacement reaction because the iron (Fe) in Fe2O3 is displaced by the hydrogen (H) in H2 to form Fe and H2O. In single displacement reactions, one element replaces another in a compound. Choice A, Combustion, involves a reaction with oxygen typically producing heat, light, and often a flame. Choice B, Decomposition, is when a compound breaks down into simpler substances. Choice D, Redox reaction, involves both reduction and oxidation reactions happening simultaneously, which is not the case in the provided equation.

5. What accurately describes the Linnaean system of classification?

• A. It focuses on evolutionary relationships between organisms.
• B. It uses dichotomous keys for identification.
• C. It groups organisms based on shared functions.
• D. It emphasizes a hierarchical ranking system.

Correct answer: D

Rationale: The Linnaean system of classification, developed by Carl Linnaeus, is based on a hierarchical ranking system where organisms are grouped into categories based on shared characteristics. This system organizes organisms into a hierarchy of increasingly specific categories, from broad to narrow, such as kingdom, phylum, class, order, family, genus, and species. The emphasis on a hierarchical ranking system allows for systematic organization and classification of a wide variety of organisms based on their similarities and differences, making it easier to study and understand the diversity of life forms. Choice A is incorrect because the Linnaean system is not primarily focused on evolutionary relationships but rather on shared characteristics for classification. Choice B is incorrect because dichotomous keys are tools used for identifying organisms, not the fundamental basis of the Linnaean system. Choice C is incorrect as the Linnaean system categorizes organisms based on shared characteristics, not shared functions.

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