Nokea
Which of the following best describes the relationship among density, volume, and mass?
- A. As volume increases, density decreases.
- B. As volume decreases, density increases.
- C. An object's mass does not affect its density.
- D. As volume decreases, mass increases.
Correct Answer: B
Rationale: The correct answer is B: 'As volume decreases, density increases.' This is because density is defined as mass divided by volume. When volume decreases and mass remains constant, the ratio of mass to volume increases, leading to higher density. Choice A is incorrect because as volume increases, density typically remains constant or increases due to the mass also increasing. Choice C is incorrect because an object's density is directly influenced by its mass. Choice D is incorrect as decreasing volume does not lead to an increase in mass.
You may also like to solve these questions
Which of the following compounds often contains a carboxyl group?
- A. Carbohydrates
- B. Glycolipids
- C. Amino Acids
- D. DNA
Correct Answer: C
Rationale: The correct answer is C: Amino Acids. Amino acids, the building blocks of proteins, contain both an amine group and a carboxyl group. The carboxyl group (-COOH) is crucial for the structure and function of proteins as it participates in peptide bond formation. Carbohydrates and DNA do not typically contain carboxyl groups as a functional group. Glycolipids consist of a carbohydrate chain linked to a lipid, but they do not inherently contain a carboxyl group.
What is the role of enzymes in the body?
- A. To transport oxygen
- B. To speed up chemical reactions
- C. To regulate body temperature
- D. To store energy
Correct Answer: B
Rationale: Enzymes act as biological catalysts that speed up chemical reactions in the body. They lower the activation energy required for reactions to occur, thus facilitating processes like digestion, metabolism, and other essential functions. Choice A is incorrect as the transportation of oxygen is primarily carried out by red blood cells. Choice C is incorrect as the regulation of body temperature involves mechanisms such as sweating and shivering. Choice D is incorrect as energy storage is mainly performed by molecules like glycogen and triglycerides.
Which of the following is a special property of water?
- A. Water does not easily flow through phospholipid bilayers.
- B. A water molecule's oxygen atom does not allow fish to breathe.
- C. Water is highly cohesive, which explains its high melting point.
- D. Water cannot self-hydrolyze and decompose into hydrogen and oxygen.
Correct Answer: C
Rationale: Water is highly cohesive, meaning it is attracted to itself due to its hydrogen bonding properties. This cohesion is the reason why water has a high melting point compared to other liquids of similar molecular weight. It is crucial for the existence of life on Earth as it allows water to remain a liquid within a wide range of temperatures, providing a stable environment for biological processes to occur. Choices A, B, and D are incorrect. Water's cohesive property does not directly relate to its ability to flow through phospholipid bilayers, assist fish in breathing, or self-hydrolyze into hydrogen and oxygen.
What macromolecules are proteins that speed up chemical reactions and act as biological catalysts?
- A. Lipids
- B. Enzymes
- C. Carbohydrates
- D. Nucleic acids
Correct Answer: B
Rationale: Enzymes are proteins that act as biological catalysts, speeding up chemical reactions without being consumed in the process. Lipids, carbohydrates, and nucleic acids do not serve as proteins that function as catalysts; they have different biological roles. Lipids are primarily used for energy storage, structural components, and signaling molecules. Carbohydrates are mainly for energy storage and providing structural support. Nucleic acids are involved in genetic information storage and transfer. Therefore, the correct answer is B: Enzymes.
What are the three regions of the small intestine?
- A. Duodenum, ileum, jejunum
- B. Cecum, ileum, jejunum
- C. Duodenum, jejunum, ileum
- D. Duodenum, jejunum, colon
Correct Answer: C
Rationale: The correct answer is C: Duodenum, jejunum, ileum. The small intestine is divided into three regions: the duodenum, jejunum, and ileum. The duodenum is the initial segment where most chemical digestion takes place. The jejunum and ileum follow the duodenum and are primarily responsible for nutrient absorption. Choice A is incorrect because the order is incorrect. Choice B is incorrect because the cecum is part of the large intestine, not the small intestine. Choice D is incorrect because the colon is part of the large intestine, not the small intestine.