Nursing Elites

1. 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.

2. Muscles are connected to bones by ______, and bones are connected to each other by ______.

• A. Muscles
• B. Tendons, ligaments
• C. Muscles
• D. Ligaments

Correct answer: B

Rationale: Muscles are connected to bones by tendons, which allow the muscle to exert force on the bone for movement. Bones are connected to each other by ligaments, which provide stability and support to the joints between bones. This relationship between muscles, tendons, bones, and ligaments is essential for proper movement and function of the musculoskeletal system. Choice A is incorrect because muscles are not directly connected to bones; tendons serve as the connection between muscles and bones. Choice D is incorrect because ligaments connect bones to each other, not muscles to bones.

3. Enzymes can _ reactions.

• A. Catalyze
• B. Inhibit
• C. Stop
• D. None of the above

Correct answer: A

Rationale: Enzymes function as catalysts that promote and accelerate chemical reactions in biological systems. They do this by lowering the activation energy required for the reactions to occur, thereby speeding up the process without being consumed in the reaction. Enzymes facilitate reactions rather than inhibiting or stopping them. Therefore, the correct answer is 'Catalyze.' 'Inhibit' and 'Stop' are incorrect because enzymes do not hinder or halt reactions but rather enhance them.

4. Which statement is untrue?

• A. RNA is single-stranded.
• B. RNA contains uracil.
• C. DNA codes for proteins.
• D. DNA cannot be altered.

Correct answer: D

Rationale: DNA can be altered through various processes such as mutations, genetic engineering, and epigenetic modifications. Changes in DNA can occur naturally or through external influences, leading to variations in the genetic code. Therefore, the statement that DNA cannot be altered is untrue. Choices A, B, and C are true statements. RNA is indeed single-stranded, RNA contains uracil instead of thymine, and DNA serves as a template for protein synthesis.

5. Which of the following molecules is an important component of the plasma membrane?

• A. Phospholipids
• B. Steroids
• C. Sugars
• D. Amino acids

Correct answer: A

Rationale: Phospholipids are indeed a crucial component of the plasma membrane. They have a unique structure with hydrophilic heads and hydrophobic tails, which allows them to form the lipid bilayer of the membrane. Steroids, sugars, and amino acids are not primary components of the plasma membrane. Steroids are a different type of lipid, sugars are often found in glycoproteins on the membrane surface, and amino acids are the building blocks of proteins, some of which are membrane proteins, but not the membrane itself.

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