ATI TEAS Practice Science Test

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: D

Rationale: The correct answer is D: Oxygen. 1. Oxygen has 8 electrons in total, with 2 in the first shell and 6 in the second shell, following the 2-8-8 electron configuration rule. 2. Beryllium has 4 electrons with 2 in the first shell and 2 in the second shell. 3. Carbon has 6 electrons with 2 in the first shell and 4 in the second shell. 4. Helium has 2 electrons, filling the first shell. Therefore, Oxygen is the only element among the choices that fits the description of having 2 electrons in the first shell and 6 electrons in the second shell.

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: Embryogenesis. During the first trimester of gestation, the developing organism goes through the process of embryogenesis, where the embryo forms and major organ systems begin to develop. Fertilization (B) occurs at the beginning of pregnancy, not during the first trimester. Meiosis (C) is the process of cell division that produces gametes, not directly related to the first trimester of gestation. Menstruation (D) is the shedding of the uterine lining if fertilization does not occur, not a developmental process during pregnancy.

Correct Answer: B

Rationale: The correct answer is B because endocrine glands release hormones directly into the bloodstream. Therefore, an extensive network of blood vessels is necessary to facilitate the direct release of hormones into the blood for systemic circulation. The other choices are incorrect because: A: Filtering waste from the blood is the function of the kidneys, not the endocrine glands. C: Blood does not "empty" into the endocrine system; rather, hormones are released into the bloodstream. D: Endocrine glands do not filter waste; instead, they produce and release hormones into the blood for various physiological functions.