Nursing Elites

1. Which statement regarding energy content is true?

• A. Decomposers < secondary consumers
• B. Primary consumers < producers
• C. Producers > secondary consumers
• D. Secondary consumers < primary consumers

Correct answer: C

Rationale: The correct answer is C: "Producers > secondary consumers." Producers, like plants, are the foundation of the energy pyramid, containing the highest energy content in an ecosystem. They convert solar energy into chemical energy through photosynthesis. Secondary consumers, being organisms that feed on other organisms, have lower energy content compared to producers. This hierarchy in energy content is due to the transfer of energy through trophic levels. Choice A is incorrect because decomposers, though essential for nutrient recycling, typically have lower energy content than secondary consumers. Choice B is incorrect because primary consumers, which feed directly on producers, have lower energy content than producers. Choice D is incorrect because secondary consumers have lower energy content compared to primary consumers.

2. Beeswax is an example of what kind of molecule?

• A. Lipid
• B. Carbohydrate
• C. Protein
• D. Nucleic acid

Correct answer: A

Rationale: Beeswax is primarily composed of esters of long-chain aliphatic alcohols and fatty acids, making it a type of lipid. Lipids are a diverse group of molecules that are hydrophobic in nature and have important functions in energy storage, signaling, and forming cellular membranes. Beeswax's chemical composition and properties categorize it as a lipid rather than a carbohydrate, protein, or nucleic acid. Carbohydrates are composed of sugars, proteins are made up of amino acids, and nucleic acids consist of nucleotides; none of which match the chemical composition of beeswax.

3. What is the binding membrane of an animal cell called?

• A. Biological membrane
• B. Cell coat
• C. Unit membrane
• D. Plasma membrane

Correct answer: D

Rationale: The correct answer is D: Plasma membrane. The plasma membrane surrounds the cell and acts as an interface between the living interior of the cell and the nonliving exterior. It plays a vital role in maintaining the cell's integrity, regulating the passage of substances in and out of the cell, and facilitating communication with other cells. Choices A, B, and C are incorrect because the term 'plasma membrane' specifically refers to the binding membrane of an animal cell, distinguishing it from other types of membranes or coatings found in cells.

4. Which molecules contain only carbon, hydrogen, and oxygen?

• A. Lipids and proteins
• B. Carbohydrates and lipids
• C. Proteins and carbohydrates
• D. Nucleic acids and proteins

Correct answer: B

Rationale: Carbohydrates and lipids are the molecules that contain only carbon, hydrogen, and oxygen. Carbohydrates such as sugars and starches are made up of carbon, hydrogen, and oxygen in a ratio of 1:2:1, while lipids such as fats and oils are composed of carbon, hydrogen, and oxygen as well. Lipids typically contain more carbon and hydrogen atoms compared to oxygen atoms. Proteins contain nitrogen in addition to carbon, hydrogen, and oxygen, while nucleic acids contain phosphorus in addition to carbon, hydrogen, and oxygen. Therefore, choices A, C, and D are incorrect as they include molecules that contain elements other than carbon, hydrogen, and oxygen.

5. During which phase is the chromosome number reduced from diploid to haploid?

• A. S phase
• B. interphase
• C. mitosis
• D. meiosis I

Correct answer: D

Rationale: The correct answer is 'meiosis I.' During meiosis I, the chromosome number is reduced from diploid to haploid through two rounds of division. Choice A ('S phase') is incorrect as the S phase is part of the cell cycle where DNA is replicated. Choice B ('interphase') is also incorrect as interphase is the phase where the cell prepares for division. Choice C ('mitosis') is incorrect as mitosis is a process where a diploid cell divides to produce two identical diploid daughter cells, maintaining the chromosome number.

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