Nursing Elites

1. Genes control heredity in man and other organisms. This gene is ___

• A. A segment of DNA
• B. A bead-like structure on the chromosomes
• C. A protein molecule
• D. A segment of RNA

Correct answer: A

Rationale: Genes are sections of DNA that contain instructions for building and operating living organisms. These sections of DNA contain the genetic information that is passed on from one generation to the next. Genes are composed of specific sequences of nucleotides within the DNA molecule. Therefore, genes are best described as segments of DNA. Choice A is correct. Choice B is incorrect because genes are not bead-like structures on chromosomes but specific sequences of DNA. Choice C is incorrect because genes are not protein molecules but rather sequences of nucleotides. Choice D is incorrect because genes are not segments of RNA but DNA.

2. A child is sick. They have a body temperature that exceeds 37ºC. The body senses this and begins to sweat in order to lower the temperature. What is this an example of?

• A. Positive feedback loop
• B. Negative feedback loop
• C. Both
• D. None of the above

Correct answer: B

Rationale: This is an example of a negative feedback loop. In a negative feedback loop, the body's response (sweating) works to counteract the initial stimulus of a high body temperature by cooling the body down. The goal is to return the body to homeostasis, maintaining a stable internal environment. Positive feedback loops amplify the initial stimulus rather than counteracting it, which is not the case here. Therefore, choices A and C are incorrect. Choice D is also incorrect as the situation described fits the characteristics of a negative feedback loop.

3. What is the term for the movement of ions and other molecular substances across cell membranes without the need for energy?

• A. Active Transport
• B. Passive Transport
• C. Diffusion
• D. Osmosis

Correct answer: B

Rationale: Passive transport refers to the movement of substances across cell membranes without the need for energy input. In contrast, active transport, choice A, requires energy to move substances against their concentration gradient. Diffusion, choice C, is a type of passive transport where substances move from an area of high concentration to low concentration. Osmosis, choice D, specifically refers to the movement of water molecules across a selectively permeable membrane.

4. Whose energy efficiency is greater?

• A. Herbivore
• B. Carnivore
• C. Omnivore
• D. Decomposer

Correct answer: D

Rationale: Decomposers have the greatest efficiency of energy among the given options. Decomposers break down organic matter, such as dead plants and animals, into simpler substances through the process of decomposition. This breakdown process results in the release of nutrients back into the ecosystem, making energy more readily available for other organisms to use. In contrast, herbivores, carnivores, and omnivores all derive their energy from the consumption of other living organisms, making their energy efficiency lower than that of decomposers. Herbivores consume plants for energy, which involves energy loss due to inefficiencies in converting plant matter into usable energy. Carnivores consume herbivores or other carnivores, leading to further energy loss through each trophic level. Omnivores consume both plant and animal matter, but their energy efficiency is still lower than decomposers because of the energy loss associated with consuming living organisms. Decomposers play a crucial role in recycling nutrients and energy in ecosystems, making them highly efficient in the utilization of energy.

5. What organelle is responsible for packaging, processing, and shipping?

• A. Nucleus
• B. Golgi Apparatus
• C. Endoplasmic Reticulum
• D. Ribosomes

Correct answer: B

Rationale: The Golgi Apparatus is the correct answer. It is responsible for packaging, processing, and shipping proteins and lipids within the cell. The nucleus houses genetic material, the endoplasmic reticulum is involved in protein synthesis and lipid metabolism, and ribosomes are responsible for protein synthesis. Therefore, choices A, C, and D are not the correct answers for the functions of packaging, processing, and shipping.

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