Which bond is formed by a positively charged metal ion and negatively charged nonmetal ion?
- A. Ionic bond
- B. Covalent bond
- C. Functional group
- D. Metallic bond
Correct Answer: A
Rationale: The correct answer is an ionic bond. An ionic bond is formed when a positively charged metal ion joins with a negatively charged nonmetal ion, resulting in a transfer of electrons. In contrast, a covalent bond involves sharing electrons between atoms rather than complete transfer. Functional groups are specific groups of atoms within molecules that determine the molecule's chemical properties. Metallic bonds occur between metal atoms where electrons are shared across a delocalized electron cloud.
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In comparison to infants born to women of normal weight, infants born to obese women are _____.
- A. less likely to have heart defects
- B. more likely to be of very low birthweight
- C. less likely to experience a complicated birth
- D. more likely to have neural tube defects
Correct Answer: D
Rationale: Infants born to obese women are more likely to have neural tube defects compared to infants born to women of normal weight. This increased risk is attributed to factors such as poor maternal nutrition and increased inflammation during pregnancy. Choice A is incorrect because infants born to obese women have a higher risk of heart defects. Choice B is incorrect as infants born to obese women are more likely to have higher birthweights. Choice C is incorrect as obese women are more likely to experience complications during birth.
High intakes of which of the following interfere with copper absorption and can lead to a deficiency?
- A. chromium
- B. sodium
- C. zinc
- D. manganese
Correct Answer: C
Rationale: The correct answer is C, zinc. High intakes of zinc can interfere with copper absorption, potentially leading to copper deficiency. Copper is essential for various bodily functions, including iron metabolism. Choice A, chromium, is incorrect because chromium does not interfere with copper absorption. Choice B, sodium, and Choice D, manganese, are also incorrect as they do not interfere with copper absorption.
Which vitamin is essential for proper blood clotting?
- A. Vitamin A
- B. Vitamin E
- C. Vitamin K
- D. Vitamin C
Correct Answer: C
Rationale: Vitamin K is vital for the synthesis of clotting factors, which are necessary for proper blood clotting. Vitamin A (Choice A) is important for vision and skin health, not blood clotting. Vitamin E (Choice B) is an antioxidant that helps protect cells from damage but is not directly involved in blood clotting. Vitamin C (Choice D) is essential for collagen synthesis and a healthy immune system, but it does not play a direct role in blood clotting.
What are the best food sources of magnesium?
- A. oils, bananas, and pork
- B. pizza, potatoes, and tomatoes
- C. milk, rice, and apples
- D. legumes, whole grains, and chocolate
Correct Answer: D
Rationale: The correct answer is D: legumes, whole grains, and chocolate. These foods are rich sources of magnesium, an essential mineral that plays a role in over 300 biochemical reactions in the body. Choices A, B, and C do not contain as high levels of magnesium compared to legumes, whole grains, and chocolate.
Each statement accurately describes the physical effects of food on periodontal health, except one. Which is the exception?
- A. Supragingival plaque biofilm adhesion is influenced by frequent consumption of monosaccharides
- B. Supragingival plaque biofilm adhesion is influenced by frequent consumption of disaccharides
- C. Poor nutrition has an adverse effect on the periodontium
- D. Chewing soft, spongy foods stimulates salivary flow
Correct Answer: D
Rationale: The correct answer is D. Chewing soft, spongy foods does not stimulate salivary flow; rather, firm, fibrous foods like fruits and vegetables do. Soft foods can stick to teeth, promoting plaque buildup. Choices A, B, and C are accurate: Supragingival plaque biofilm adhesion is influenced by both monosaccharides and disaccharides, while poor nutrition can indeed have adverse effects on the periodontium.