TEAS 7 practice test free science

Correct Answer: C

Rationale: The correct answer is C, Frequency. The energy of a wave is determined by its frequency, not its amplitude, wavelength, or velocity. According to the equation E = h*f, where E is energy, h is Planck's constant, and f is frequency, the energy of a wave is directly proportional to its frequency. Higher frequency waves carry more energy, while lower frequency waves carry less energy. Therefore, frequency plays a crucial role in determining the energy content of a wave, making it the correct choice in this context.

Correct Answer: C

Rationale: Reactivity refers to a substance's ability to undergo a change that transforms it into a different substance through a chemical reaction. In this context, reactivity specifically refers to the chemical behavior of a substance. Density, mass, and volume are physical properties of a substance and do not describe its ability to undergo a chemical change. Density is the mass per unit volume, mass is the amount of matter in an object, and volume is the amount of space occupied by an object. Therefore, reactivity is the most appropriate term to describe a substance's ability to undergo a transformation into a different substance.

Correct Answer: C

Rationale: Vaccines primarily function by stimulating the immune system to develop immunological memory to a specific pathogen. When a vaccine is administered, it exposes the immune system to a harmless version of a pathogen or a piece of it. This exposure triggers the immune response, leading to the production of antibodies and memory cells specific to that pathogen. Choice A is incorrect because vaccines do not create a physical barrier; rather, they prepare the immune system to recognize and fight specific pathogens. Choice B is incorrect as vaccines do trigger an immune response, but the primary goal is to create memory rather than inflammation. Choice D is incorrect as vaccines do not directly activate phagocytes; instead, they stimulate the immune system to generate a targeted response against a particular pathogen.

Correct Answer: B

Rationale: The correct answer is B: Iron. Hemoglobin, the protein responsible for carrying oxygen in red blood cells, contains iron in its heme group, contributing to the blood's characteristic red color. Magnesium (choice A), copper (choice C), and zinc (choice D) are not responsible for the red color of blood. Magnesium is an essential mineral involved in various physiological processes, copper is a trace element important for enzyme function, and zinc is a micronutrient essential for multiple cellular functions but not related to the red color of blood.

Correct Answer: A

Rationale: Beta-oxidation is the correct term for the process of breaking down fatty acids into acetyl-CoA molecules. This essential process takes place in the mitochondria and is a pivotal step in fatty acid metabolism for energy production. Lipolysis, however, refers to the breakdown of fats into fatty acids and glycerol but does not specifically involve the conversion of fatty acids into acetyl-CoA. Carbohydrate catabolism focuses on breaking down carbohydrates into glucose for energy production and is not directly linked to the conversion of fatty acids into acetyl-CoA. Nucleic acid catabolism involves the breakdown of nucleic acids into nucleotides and is not associated with the conversion of fatty acids into acetyl-CoA.