ATI TEAS Practice Science Test

Correct Answer: A

Rationale: The hypodermis is primarily composed of adipose tissue, which is a type of connective tissue. Adipose tissue serves as a layer of insulation and energy storage in the body. It helps regulate body temperature and provides cushioning for organs. Adipose tissue is the main component of the hypodermis, making choice A the correct answer. Choices B, C, and D are incorrect because the hypodermis is not primarily composed of regular connective tissue, epithelial tissue, or muscle tissue.

Correct Answer: A

Rationale: The correct answer is A: They are small and soluble. Small molecules can easily diffuse across cell membranes, while soluble molecules can dissolve in the cell's aqueous environment. This combination allows the signals to pass through the membrane and bind to intracellular receptors. Choice B (large and soluble) is incorrect because large molecules have difficulty crossing the membrane. Choices C (small and insoluble) and D (large and insoluble) are incorrect as they do not facilitate the passage of signals across the cell membrane for binding to intracellular receptors.

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: B

Rationale: The correct unit to measure how far a person can run in 30 minutes is kilometers. Kilometers are commonly used to measure shorter distances, making it suitable for this scenario. Gigameters, Megameters, and Terameters are all much larger units of distance measurement, which would not be appropriate for measuring the relatively small distance a person can run in 30 minutes. Kilometers offer a reasonable scale for measuring human running distances accurately within a small range.

Correct Answer: C

Rationale: The correct order is C: Thrombocytes, erythrocytes, and leukocytes. Thrombocytes (platelets) are the smallest, followed by erythrocytes (red blood cells), then leukocytes (white blood cells). This order is based on the size of these blood cell types, with thrombocytes being the smallest and leukocytes being the largest. Thrombocytes play a crucial role in blood clotting, erythrocytes are responsible for oxygen transport, and leukocytes are essential for immune function. Incorrect choices: A: Incorrect order; leukocytes are the largest, not the smallest. B: Incorrect order; thrombocytes are the smallest, not the largest. D: Incorrect order; leukocytes are larger than erythrocytes, so the order is incorrect.