Practice TEAS Science Test

Correct Answer: A

Rationale: The correct answer is A: Mediastinum. The mediastinum is the space between the lungs that contains vital structures such as the heart, major blood vessels, esophagus, and trachea. It separates the lungs into right and left compartments. The pericardial cavity (B) is the space that surrounds the heart within the mediastinum. The pleural cavity (C) is the space between the lungs and the chest wall, not between the lungs themselves. Thoracic space (D) is a vague term and does not specifically refer to the space between the lungs.

Correct Answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from the air we breathe passes into the blood vessels surrounding the alveoli, while carbon dioxide from the blood moves into the alveoli to be exhaled. The other choices are incorrect because: A: Trachea is the windpipe that carries air to and from the lungs, but gas exchange does not occur there. C: Bronchioles are small air passages that branch off the bronchi, leading air to the alveoli, but they are not the site of gas exchange. D: Diaphragm is a muscle that helps with breathing by expanding and contracting the chest cavity, but it is not directly involved in gas exchange.

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: D

Rationale: The correct answer is D: Recessive Inheritance. Mendelian inheritance follows the principles proposed by Gregor Mendel, where traits are determined by pairs of genes, with one being dominant and the other recessive. In recessive inheritance, an individual must inherit two copies of the recessive allele to exhibit the trait. This type of inheritance follows Mendel's laws of segregation and independent assortment. In contrast, incomplete dominance (A) shows blending of traits, polygenic alleles (B) involve multiple genes contributing to a single trait, and combination inheritance (C) is not a recognized term in Mendelian genetics.

Correct Answer: D

Rationale: The correct answer is D: Pia mater. Pia mater is the innermost meningeal layer that is a thin membrane containing nerves and blood vessels. It directly covers the brain and spinal cord, supplying nourishment to the underlying cells. Arachnoid mater (A) is the middle meningeal layer that does not contain nerves and blood vessels. Dura mater (B) is the tough outermost layer that does not supply nourishment. Periosteum (C) is a connective tissue covering bones, not the meninges.