Nursing Elites

1. Which types of molecules can move through a cell membrane by passive transport?

• A. Complex sugars
• B. Non-lipid soluble molecules
• C. Oxygen
• D. Molecules moving from areas of low concentration to areas of high concentration

Correct answer: C

Rationale: The correct answer is C: Oxygen. Small, non-polar molecules like oxygen can easily pass through the cell membrane by passive transport as they move down their concentration gradient without the need for energy input. Complex sugars (choice A) are typically too large to pass through the membrane by passive transport. Non-lipid soluble molecules (choice B) may require active transport mechanisms. Choice D describes active transport, where molecules move against their concentration gradient, requiring energy input.

2. Adaptive radiation refers to the evolutionary process where:

• A. A single ancestral species diversifies into multiple descendant species due to ecological pressures in a heterogeneous environment.
• B. Two unrelated species evolve similar adaptations in response to similar environments, leading to convergent evolution.
• C. A population becomes increasingly well-adapted to its current environment through continued natural selection.
• D. The fossil record exhibits gaps or missing links in the evolutionary history of a lineage.

Correct answer: A

Rationale: - Adaptive radiation is a process where a single ancestral species diversifies into multiple descendant species to exploit different ecological niches within a heterogeneous environment. - This diversification occurs due to the different selective pressures present in various habitats, leading to the evolution of distinct traits and adaptations in different descendant species. - Option A accurately describes the process of adaptive radiation, where the initial species undergoes rapid speciation to occupy different ecological roles and adapt to diverse environmental conditions. - Options B, C, and D do not accurately describe adaptive radiation but refer to other evolutionary processes such as convergent evolution, natural selection, and gaps in the fossil record, respectively.

3. Which region of the small intestine is the primary site of absorption?

• A. Duodenum
• B. Jejunum
• C. Ileum
• D. Cecum

Correct answer: B

Rationale: The jejunum is the correct answer. It is the primary site of nutrient absorption in the small intestine. The duodenum mainly facilitates digestion, the ileum is responsible for further absorption, while the cecum is part of the large intestine and not involved in nutrient absorption.

4. Which of the following terms describes stem cells that have the ability to develop into any cell found in the human body?

• A. Totipotent stem cells
• B. Multipotent stem cells
• C. Pluripotent stem cells
• D. Hematopoietic stem cells

Correct answer: A

Rationale: Totipotent stem cells have the unique ability to differentiate into any cell type in the human body and can generate a complete organism. They are considered the most versatile type of stem cells, capable of developing into all cell types, including extraembryonic tissues. Choice A, Totipotent stem cells, is the correct answer as it specifically describes stem cells with the broadest differentiation potential. Choice B, Multipotent stem cells, refers to stem cells that can differentiate into a limited range of cell types. Choice C, Pluripotent stem cells, can give rise to almost all cell types, but not the complete organism like totipotent stem cells. Choice D, Hematopoietic stem cells, are a type of multipotent stem cells that give rise to various blood cell types, but do not have the same broad differentiation potential as totipotent stem cells.

5. The patella, commonly known as the kneecap, is an example of a:

• A. Sesamoid bone
• B. Long bone
• C. Short bone
• D. Irregular bone

Correct answer: A

Rationale: The patella, also known as the kneecap, is an example of a sesamoid bone. Sesamoid bones develop within tendons, such as the patellar tendon in this case. The patella is embedded in the tendon of the quadriceps muscle, enhancing the mechanical advantage of the muscle and protecting the knee joint. Long bones, like the femur, are characterized by their elongated shape with growth plates at the ends. Short bones, such as those in the wrist and ankle, are cube-shaped bones. Irregular bones, like vertebrae, do not fit into the other bone shape categories due to their unique shapes and functions.

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