Practice TEAS Science Test

Correct Answer: B

Rationale: The correct answer is B: To absorb water and form feces. The large intestine mainly functions to absorb water from the indigestible food residue and solidify it into feces before excretion. This process helps in maintaining the body's fluid balance and preventing dehydration. Why the other choices are incorrect: A: The absorption of proteins primarily occurs in the small intestine, not the large intestine. C: Enzymes for digestion are produced in the pancreas and small intestine, not in the large intestine. D: Fat storage is mainly regulated by adipose tissue throughout the body, not the large intestine.

Correct Answer: B

Rationale: The correct answer is B: Larynx. The voice box, also known as the larynx, is responsible for producing sound by manipulating airflow from the lungs. The other choices are incorrect because: A: Alveoli are small air sacs in the lungs for gas exchange. C: Trachea is the windpipe that carries air to and from the lungs. D: Pharynx is the throat region where the nasal and oral cavities meet.

Correct Answer: B

Rationale: Iron is the correct answer because it is an essential component of hemoglobin, the protein in red blood cells responsible for transporting oxygen throughout the body. Without iron, the body cannot produce enough hemoglobin, leading to anemia. Calcium, potassium, and sodium do not play a direct role in hemoglobin synthesis. Calcium is important for bone health, potassium is crucial for nerve and muscle function, and sodium helps regulate fluid balance. Iron is the only element among the choices that is directly involved in hemoglobin formation.

Correct Answer: B

Rationale: The correct answer is B: Medulla oblongata. The medulla oblongata, located in the brainstem, controls essential functions like breathing and heart rate. It contains centers that regulate these automatic processes. The cerebrum (A) is responsible for higher brain functions, not controlling basic physiological functions. The thalamus (C) serves as a relay station for sensory information, not for regulating breathing and heart rate. The cerebellum (D) plays a role in coordination and movement, not in controlling vital functions like breathing and heart rate.

Correct Answer: C

Rationale: The correct answer is C: IgG. IgG is the only antibody that can cross the placenta due to its smaller size and ability to bind to neonatal Fc receptors. This allows for passive immunity to be transferred from mother to fetus. IgA is mainly found in mucosal secretions, IgD functions as a B cell receptor, and IgM is primarily involved in the primary immune response. IgG is the most abundant antibody in the circulation and plays a crucial role in protecting the fetus from infections.