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Which element is used in jewelry due to its malleability and resistance to tarnish?
- A. Iron
- B. Copper
- C. Gold
- D. Silver
Correct Answer: C
Rationale: Gold is the correct answer. Gold is a popular choice for jewelry due to its exceptional malleability, allowing it to be easily shaped into intricate designs. Moreover, gold is resistant to tarnish, ensuring the jewelry retains its beauty over time. Iron is not commonly used in jewelry due to its susceptibility to rusting. Copper is also not as popular in jewelry making as gold due to its tendency to tarnish and cause skin discoloration. While silver is used in jewelry, it is more prone to tarnish compared to gold, making it less ideal for long-lasting pieces.
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Which protein complex in the sarcomere is responsible for the thick filament?
- A. Actin
- B. Myosin
- C. Tropomyosin
- D. Troponin
Correct Answer: B
Rationale: Myosin is the protein complex responsible for the thick filament in the sarcomere. It interacts with actin, another protein in the sarcomere, to generate the sliding movement that results in muscle contraction. Actin is a thin filament protein that interacts with myosin to create the sliding filament mechanism. Tropomyosin and troponin are regulatory proteins that regulate muscle contraction by controlling the interaction between actin and myosin, rather than directly being responsible for the thick filament.
Which organ produces insulin and glucagon?
- A. Salivary Glands
- B. Liver
- C. Gallbladder
- D. Pancreas
Correct Answer: D
Rationale: The correct answer is D, Pancreas. The pancreas is the organ responsible for producing the hormones insulin and glucagon. Insulin functions to lower blood sugar levels by facilitating the uptake of glucose by cells for energy production. On the other hand, glucagon works to raise blood sugar levels by prompting the liver to release stored glucose into the bloodstream. The pancreas is a vital organ in the endocrine system, playing a crucial role in maintaining appropriate blood sugar levels in the body. Choices A, B, and C are incorrect as the salivary glands produce saliva, the liver is involved in various metabolic functions, and the gallbladder stores bile produced by the liver, but none of these organs produce insulin and glucagon.
What is molarity a measure of in a solution?
- A. Volume of the solvent
- B. Amount of solute
- C. Concentration of solute
- D. Temperature of the solution
Correct Answer: C
Rationale: Molarity is a measure of the concentration of a solute in a solution. It is defined as the number of moles of solute per liter of solution. Molarity is not a measure of the volume of the solvent (choice A), the amount of solute (choice B), or the temperature of the solution (choice D). Therefore, the correct answer is the concentration of solute (choice C) as molarity specifically quantifies the solute concentration in a solution.
In experimental design, which variable is measured as a possible effect and is plotted on the y-axis?
- A. Independent, x
- B. Independent, y
- C. Dependent, x
- D. Dependent, y
Correct Answer: D
Rationale: The correct answer is D: 'Dependent, y.' In experimental design, the dependent variable is the outcome that is being measured or observed as a result of changes in the independent variable. It is typically plotted on the y-axis of a graph to represent the effect or response to the changes in the independent variable. Choice A 'Independent, x' is incorrect because the independent variable is the variable manipulated by the experimenter and is usually plotted on the x-axis. Choice B 'Independent, y' is incorrect as the independent variable is not plotted on the y-axis. Choice C 'Dependent, x' is incorrect because the dependent variable is not typically plotted on the x-axis in experimental design.
What is the difference between polygenic inheritance and pleiotropy?
- A. Polygenic inheritance involves multiple genes influencing one trait, while pleiotropy involves one gene affecting multiple traits.
- B. Polygenic inheritance is found in simple Mendelian traits, while pleiotropy is found in complex traits.
- C. Polygenic inheritance is always quantitative, while pleiotropy can be qualitative or quantitative.
- D. Both involve multiple genes and multiple traits, but the specific mechanisms differ
Correct Answer: A
Rationale: - Polygenic inheritance refers to the situation where a trait is influenced by multiple genes, each contributing a small effect to the phenotype. These traits often show continuous variation and are not easily categorized into discrete categories.
- Pleiotropy, on the other hand, occurs when a single gene influences multiple, seemingly unrelated traits. This means that a mutation in one gene can lead to multiple phenotypic effects across different traits or characteristics.
- Therefore, the key difference between polygenic inheritance and pleiotropy lies in the number of genes involved in influencing a trait (multiple genes in polygenic inheritance vs. one gene in pleiotropy) and the direction of influence (one trait affected by multiple genes in polygenic inheritance vs. multiple traits affected by one gene in pleiotropy).