ATI TEAS Practice Science Test

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: C

Rationale: The independent variable is the factor that is intentionally changed by the researcher. In this study, the type of road salt used is the independent variable because it is what the researcher is manipulating to observe its effect on the deicing time. The researcher can control and vary the type of road salt to measure its impact on the deicing process. The other choices are not the independent variable because: A (Deicing time period) is the dependent variable, B (Road used for deicing) is not something that the researcher is intentionally changing, and D (Amount of road salt used) is a controlled variable that can be adjusted but not the main factor being manipulated.

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: B

Rationale: The correct answer is B because urine is formed in the kidney during the process of fluid filling the collecting duct. This is where the final concentration and composition of urine are regulated. Before reaching the collecting duct, the initial filtration of blood occurs in the glomerulus (eliminating options C) and the fluid does not become urine until it has passed through the collecting duct (eliminating options A and D). So, the correct sequence is filtration in the glomerulus, reabsorption and secretion in the tubules, and final urine formation in the collecting duct.

Correct Answer: C

Rationale: The correct answer is C: Epithelial cells. Epithelial cells are found in the hair bulb and are responsible for hair growth because they undergo rapid cell division and differentiation to form the hair shaft. Basal cells (choice A) are a type of epithelial cell found in the skin, but they mainly function in the regeneration of the epidermis. Epidermal cells (choice B) refer to the outer layer of the skin and do not play a direct role in hair growth. Merkel cells (choice D) are specialized touch receptors found in the skin, but they are not involved in hair growth. In summary, epithelial cells in the hair bulb are specifically designed for hair growth through their rapid division and differentiation process.