Nursing Elites

1. Which type of cell has a nucleus but lacks membrane-bound organelles?

• A. Plant cell
• B. Prokaryotic cell
• C. Animal cell
• D. Fungal cell

Correct answer: B

Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus that is not enclosed within a membrane (nuclear envelope) and lacking membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant, animal, and fungal cells are eukaryotic cells, which have a true nucleus enclosed within a nuclear envelope and contain membrane-bound organelles. Therefore, options A, C, and D are incorrect as they all represent eukaryotic cells that possess membrane-bound organelles.

2. Which of these pairs represents an example of convergent evolution?

• A. Humans and chimpanzees
• B. Bats and birds
• C. Dolphins and sharks
• D. Snakes and earthworms

Correct answer: B

Rationale: Convergent evolution refers to the process by which different species independently evolve similar traits or characteristics due to similar environmental pressures. In the case of bats and birds, both have evolved wings for flight despite not sharing a recent common ancestor with wings. Bats are mammals, while birds are avians, yet they both have wings adapted for flight, which is a classic example of convergent evolution. A) Humans and chimpanzees share a common ancestor and have not independently evolved similar traits. C) Dolphins and sharks are not closely related, and their similarities are due to adaptations to their aquatic environment rather than convergent evolution. D) Snakes and earthworms belong to different classes (reptiles and annelids, respectively) and do not share recent common ancestors, making their similarities not a result of convergent evolution.

3. Which types of glial cells are in the PNS?

• A. Schwann cells, satellite cells
• B. Astrocytes, oligodendrocytes
• C. Microglia, ependymal cells
• D. Satellite cells, oligodendrocytes

Correct answer: A

Rationale: The correct answer is A, which includes Schwann cells and satellite cells as the types of glial cells found in the peripheral nervous system. Schwann cells support neurons and myelinate axons, while satellite cells provide structural support and regulate the microenvironment around neurons in the PNS. Options B, C, and D are incorrect as they refer to glial cell types that are typically found in the central nervous system, not the peripheral nervous system. Astrocytes and oligodendrocytes are primarily located in the CNS, where they perform functions such as providing structural support and forming the blood-brain barrier. Microglia are immune cells found in the CNS responsible for immune defense and maintenance of neural environment, while ependymal cells line the cerebral ventricles and the central canal of the spinal cord, contributing to the production and circulation of cerebrospinal fluid.

4. Which property of a substance describes its ability to conduct heat or electricity?

• A. Reactivity
• B. Conductivity
• C. Density
• D. Viscosity

Correct answer: B

Rationale: Conductivity is the correct property that describes a substance's ability to conduct heat or electricity. Reactivity is related to how readily a substance undergoes chemical reactions, not its ability to conduct heat or electricity. Density refers to the mass per unit volume of a substance, which is different from its ability to conduct heat or electricity. Viscosity measures a substance's resistance to flow, not its ability to conduct heat or electricity.

5. Which of the following describes the term allele?

• A. A specific form of a gene that can exist at a particular locus
• B. An inheritable variation of a gene
• C. A grouping of various genes
• D. Variations of complementary base pairs

Correct answer: B

Rationale: The correct answer is B. Alleles are different forms of a gene that can exist at a specific locus. They represent variations of a gene and are inheritable. Choice A is incorrect as it does not fully capture the concept of an allele, which is a specific form of a gene rather than a substitution. Choice C is incorrect as alleles are not a grouping of various genes but rather different forms of a single gene at a specific locus. Choice D is also incorrect as it does not accurately describe alleles; alleles are variations of genes, not base pairs.

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