Nursing Elites

1. Two organisms live in a relationship from which both benefit. What is this called?

• A. Mutualism
• B. Parasitism
• C. Commensalism
• D. Competition

Correct answer: A

Rationale: Mutualism is a type of symbiotic relationship between two organisms in which both parties benefit from the association. It is a mutually beneficial interaction where both organisms gain something valuable, such as food, protection, or some other resource. This contrasts with parasitism, where one organism benefits at the expense of the other, commensalism, where one organism benefits while the other is unaffected, and competition, where both organisms are negatively affected by their interaction.

2. What happens to messenger RNA when it reaches the cytoplasm?

• A. It attaches to a ribosome.
• B. It unzips, exposing nitrogen bases.
• C. It pairs with the DNA bases.
• D. It pulls free of the DNA strand.

Correct answer: A

Rationale: Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm. When mRNA reaches the cytoplasm, it attaches to a ribosome. The ribosome functions as the site for protein synthesis through translation, where the genetic code carried by mRNA is read and translated into a specific sequence of amino acids. Choices B, C, and D are incorrect because mRNA does not unzip, expose nitrogen bases, pair with DNA bases, or pull free of the DNA strand in the cytoplasm. The primary function of mRNA in the cytoplasm is to serve as a template for protein synthesis by binding to ribosomes.

3. Why does cytokinesis happen?

• A. DNA can duplicate
• B. Organelles can convert energy
• C. Bacteria can be killed
• D. Daughter cells can divide

Correct answer: D

Rationale: Cytokinesis happens at the end of mitosis to physically separate the newly formed daughter cells. This allows the cell to divide into two separate daughter cells, each containing a complete set of genetic material (DNA) and organelles. The purpose of cytokinesis is to ensure that each daughter cell receives the necessary components to function independently. Choices A, B, and C are incorrect because cytokinesis does not directly involve DNA duplication, organelles converting energy, or killing bacteria.

4. What helps the cell maintain its shape and allows it to adapt?

• A. Microfilaments
• B. Cytoplasm
• C. Cytoskeleton
• D. Centrioles

Correct answer: C

Rationale: The cytoskeleton is the correct answer. It provides structural support to the cell, helps maintain its shape, and enables it to adapt to different environments. Microfilaments are part of the cytoskeleton, but they alone do not encompass the entire cytoskeleton's functions. Cytoplasm is the fluid inside the cell where organelles are suspended and is not directly responsible for maintaining cell shape. Centrioles are involved in cell division and do not primarily contribute to maintaining the cell's shape and adaptation.

5. Which of the following is always true about molecules?

• A. They cannot travel through all cell membranes
• B. They move from low concentration to high concentration without using energy
• C. They move from high concentration to low concentration without using energy
• D. They cannot move

Correct answer: C

Rationale: The statement that molecules move from high concentration to low concentration without using energy is always true due to the natural process of diffusion. This movement occurs to reach equilibrium and does not require any additional energy input directly from the molecule itself. Choice A is incorrect because not all molecules can travel through all cell membranes. Choice B is incorrect as molecules typically move from high concentration to low concentration in a process known as passive transport. Choice D is incorrect as molecules are in constant motion due to factors like temperature and kinetic energy.

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