TEAS Practice Test Science

Correct Answer: C

Rationale: The correct answer is C: Pluripotent stem cells. Pluripotent stem cells can differentiate into many different cell types but cannot form a complete organism. They have the ability to give rise to cells of all three germ layers. Totipotent stem cells (A) can form a complete organism, including both embryonic and extra-embryonic tissues. Multipotent stem cells (B) can develop into a limited range of cell types. Hematopoietic stem cells (D) specifically give rise to blood cells and their progenitors, so they are more specialized compared to pluripotent stem cells.

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 rib cage protects the vital organs such as the lungs and heart by providing a sturdy barrier against external impact. The ribs act as a shield, preventing injuries to these crucial organs. Additionally, the rib cage also aids in the process of respiration by expanding and contracting to allow the lungs to inflate and deflate during breathing. Choices A, C, and D are incorrect because the primary function of the rib cage is to protect the lungs and heart, not the digestive organs, support movement, or regulate body temperature.

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: C

Rationale: The correct answer is C: Pluripotent stem cells. Pluripotent stem cells can differentiate into many different cell types but cannot form a complete organism. They have the ability to give rise to cells of all three germ layers. Totipotent stem cells (A) can form a complete organism, including both embryonic and extra-embryonic tissues. Multipotent stem cells (B) can develop into a limited range of cell types. Hematopoietic stem cells (D) specifically give rise to blood cells and their progenitors, so they are more specialized compared to pluripotent stem cells.