Practice TEAS Science Test

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.

Correct Answer: D

Rationale: The correct answer is D: Glucose. Glucose is a monosaccharide, not a biological macromolecule. Biological macromolecules are large molecules made up of smaller subunits. Glycoproteins are proteins with attached carbohydrates, DNA is a nucleic acid, and phospholipids are lipids. Glucose, being a simple sugar, is not considered a macromolecule.

Correct Answer: A

Rationale: The correct answer is A: Skin. An organ is a group of tissues that work together to perform specific functions in the body. Skin is the body's largest organ, made up of different layers that serve various functions like protection, sensation, and regulation of body temperature. Neuron (B) is a cell type, brainstem (C) is a part of the brain, and DNA (D) is a molecule, not an organ. Skin best fits the definition of an organ, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: Large intestine. The large intestine is responsible for absorbing water and forming feces as it reabsorbs water from the indigestible food particles that pass through it, leading to the formation of solid waste (feces). The stomach (A) primarily breaks down food with gastric juices. The small intestine (B) is where most nutrient absorption occurs, not water absorption for feces formation. The esophagus (D) is a muscular tube that carries food from the mouth to the stomach, with no role in water absorption or feces formation.

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.