TEAS Practice Test Science

Correct Answer: D

Rationale: When blood sugar drops, the body needs to increase glucose levels. The correct answer, D, is that the pancreas releases glucagon. Glucagon signals the liver to break down stored glycogen into glucose, raising blood sugar levels. This is a crucial mechanism to maintain blood glucose homeostasis. Other choices (A, B, C) are incorrect as they do not address the specific response needed to increase blood sugar levels when it drops.

Correct Answer: D

Rationale: The correct answer is D: Vacuole. Vacuoles are responsible for storing food, water, and other materials in the cell. They help maintain turgor pressure and regulate the cell's internal environment. Centrioles are involved in cell division, lysosomes contain digestive enzymes, and ribosomes are responsible for protein synthesis. So, A, B, and C are incorrect choices for food and water storage in the cell.

Correct Answer: A

Rationale: The independent variable is what the researcher manipulates to observe its effect on the dependent variable. In this study, the botanist is testing if temperature affects root growth. Therefore, the independent variable is temperature (choice A). The botanist will change the temperature levels to see how it influences root growth. Choices B, C, and D are not the independent variable as the botanist is not directly manipulating seedlings, light, or root length to study the effect on root growth.

Correct Answer: C

Rationale: The correct answer is C: Thymus. The thymus is responsible for maturing T cells, a type of white blood cell crucial for immune responses. The thymus is where immature T cells develop into functional T cells through a process called thymic education. The other choices are incorrect because the hypothalamus (A) is involved in regulating hormones, the pineal gland (B) regulates sleep-wake cycles, and the thyroid (D) produces hormones that regulate metabolism. These structures do not have a direct role in maturing T cells.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver produces bile, a greenish-yellow fluid that aids in digestion by breaking down fats. The pancreas (choice A) produces digestive enzymes, not bile. The gallbladder (choice C) stores and concentrates bile produced by the liver, but it does not produce bile itself. The stomach (choice D) produces gastric juices to break down food, but it does not produce bile. Therefore, the liver is the organ responsible for producing bile to aid in digestion.