Nursing Elites

1. What type of bond connects sugar and phosphate in DNA?

• A. Hydrogen
• B. Ionic
• C. Covalent
• D. Overt

Correct answer: C

Rationale: The correct answer is Covalent (C). In DNA, a covalent bond connects sugar and phosphate molecules. This bond involves the sharing of electron pairs between the atoms, providing stability to the DNA structure. Hydrogen bonds are important in DNA structure but are not the primary bond connecting sugar and phosphate. Ionic bonds involve the transfer of electrons, and 'overt' is not a term related to the bond connecting sugar and phosphate in DNA.

2. Which structure helps regulate body temperature by constricting or dilating in response to temperature changes?

• A. Sebaceous glands
• B. Hair follicles
• C. Sweat glands
• D. Langerhans cells

Correct answer: C

Rationale: Sweat glands play a crucial role in regulating body temperature by producing sweat that evaporates from the skin surface. This evaporation cools the body when it is hot and helps to maintain a stable internal temperature. Sebaceous glands produce oil to lubricate the skin, hair follicles are responsible for hair growth, and Langerhans cells are a type of immune cell in the skin. Therefore, the correct answer is 'Sweat glands' as they are specifically designed to respond to temperature changes by constricting or dilating to help regulate body temperature.

3. Which of the following processes describes the conversion of glucose to pyruvic acid during glycolysis?

• A. Glycogenesis
• B. Glycolysis
• C. Glycogenolysis
• D. Gluconeogenesis

Correct answer: B

Rationale: The correct answer is B: Glycolysis. Glycolysis is the metabolic pathway where glucose is broken down to produce pyruvic acid and ATP, generating energy in the form of ATP. Glycogenesis (choice A) is the process of glycogen synthesis, Glycogenolysis (choice C) is the breakdown of glycogen to release glucose, and Gluconeogenesis (choice D) is the synthesis of glucose from non-carbohydrate sources. Therefore, during glycolysis, glucose is converted into pyruvic acid, which is a crucial step in energy production.

4. Which hormones are responsible for stimulating the development of sex organs and secondary sex characteristics during puberty?

• A. Growth hormone
• B. Testosterone (in males) and Estrogen (in females)
• C. Insulin
• D. Thyroid hormone

Correct answer: B

Rationale: Testosterone and estrogen are the primary sex hormones responsible for the development of male and female sex organs, respectively, and the emergence of secondary sex characteristics during puberty. Growth hormone, insulin, and thyroid hormone do not directly influence the development of sex organs and secondary sex characteristics during puberty. Growth hormone primarily regulates growth and metabolism, insulin regulates blood sugar levels, and thyroid hormone controls metabolism and energy levels. Therefore, choices A, C, and D are incorrect for this question.

5. Which of the following cations is found at the center of a heme?

• A. Cr (III)
• B. Cu (II)
• C. Iron (II)
• D. Iron (III)

Correct answer: C

Rationale: The correct answer is Iron (II) (Fe2+), which is the cation found at the center of a heme group. Heme contains an iron (II) ion that is coordinated within the porphyrin ring structure. This iron ion is crucial for the function of heme in binding and transporting oxygen in hemoglobin and myoglobin. Choice A (Cr (III)) is incorrect as chromium is not typically found at the center of a heme group. Choice B (Cu (II)) is incorrect as copper is not the cation typically present in heme. Choice D (Iron (III)) is also incorrect as heme predominantly contains iron (II) at its center, not iron (III).

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