ATI TEAS Practice Science Test

Correct Answer: D

Rationale: The correct answer is D: Sucrase. Sucrose is a disaccharide composed of glucose and fructose. Sucrase is the enzyme responsible for breaking down sucrose into its constituent sugars, glucose, and fructose. Lactase (A) breaks down lactose, Maltase (B) breaks down maltose, and Peptidase (C) breaks down proteins. In this case, since we are dealing with sucrose from the birthday cake, the enzyme needed is sucrase to catalyze the breakdown of sucrose into its simpler sugars.

Correct Answer: A

Rationale: The correct answer is A: Artificial/active immunity. The MMR vaccine provides artificial immunity because it is a vaccine created in a laboratory rather than acquired naturally. It induces active immunity by stimulating the body to produce its antibodies against measles, mumps, and rubella. This type of immunity is long-lasting and provides protection by training the immune system to recognize and fight off these diseases in the future. Choice B (Artificial/passive) is incorrect because passive immunity involves receiving pre-formed antibodies rather than activating the immune system to produce its antibodies, which is the case with the MMR vaccine. Choice C (Natural/active) is incorrect because natural immunity is acquired through exposure to the actual disease, not through vaccination. Choice D (Natural/passive) is incorrect because natural passive immunity is passed from mother to baby through breast milk or placenta, not through vaccination.

Correct Answer: C

Rationale: The correct answer is C: Chromosome. A chromosome is a rod-shaped structure formed when a single DNA molecule and its associated proteins coil tightly before cell division. This coiling helps to compact the DNA and ensure it is evenly distributed to daughter cells during cell division. Centromere (A) is a specific region of a chromosome where sister chromatids are joined. Chromatid (B) refers to one of the two identical copies of a chromosome that are joined at the centromere. Gene (D) is a segment of DNA that carries the genetic information for a specific trait. Therefore, the correct answer is chromosome as it specifically describes the rod-shaped structure formed during cell division due to the coiling of DNA and proteins.

Correct Answer: A

Rationale: The correct answer is A: Forms neural circuits. Interneurons are responsible for forming connections between sensory neurons and motor neurons, creating neural circuits that allow for complex processing and coordination of signals within the central nervous system. They do not directly interact with effectors (choice B), send impulses to the CNS (choice C), or function as efferent nerve cells (choice D). Interneurons integrate and relay information within the CNS, playing a crucial role in coordinating various functions such as reflexes, sensory processing, and motor control.

Correct Answer: A

Rationale: The correct answer is A: Cell. Cells are the most basic unit of structure in living things because they are the building blocks of all living organisms. Cells perform all the necessary functions for life, such as growth, reproduction, and energy production. Organelles are structures within cells, not the basic unit themselves. Oxygen is a vital component for life but not a structural unit. Pigments are molecules that give color and have specific functions in organisms but are not the basic unit of structure. Therefore, the correct choice is A: Cell.