Practice TEAS Science Test

Correct Answer: B

Rationale: The correct answer is B: Depolarization of the SA node. The P-wave in an ECG represents atrial depolarization, which is initiated by the SA node. This electrical signal spreads through the atria causing them to contract. Choice A is incorrect because the P-wave corresponds to atrial depolarization, not repolarization. Choice C is incorrect as the QRS complex represents ventricular depolarization. Choice D is incorrect as the T-wave represents ventricular repolarization. Therefore, the SA node depolarization is accurately represented by the P-wave in an ECG.

Correct Answer: B

Rationale: The correct answer is B: Medulla oblongata. This part of the brain is located in the brainstem and is responsible for regulating essential involuntary functions such as breathing, heart rate, and blood pressure. It contains vital centers that control these functions, making it the correct choice. Rationale: 1. Cerebrum (A): The cerebrum is responsible for higher brain functions such as thinking, memory, and voluntary movements. It does not directly control involuntary functions like breathing and heart rate. 2. Cerebellum (C): The cerebellum is involved in coordination, balance, and muscle movement but does not regulate involuntary functions like breathing and heart rate. 3. Thalamus (D): The thalamus acts as a relay center for sensory information but is not primarily involved in controlling involuntary functions like breathing and heart rate. In summary, the Medulla oblongata is the correct answer because it specifically houses the centers that control vital involuntary functions, distinguishing

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: 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: B

Rationale: The correct answer is B: To filter waste from the blood. The lymphatic system includes lymph nodes and vessels that help filter out waste, toxins, and pathogens from the blood. Lymphocytes in the lymph nodes also play a key role in immune responses. The other choices (A, C, D) are incorrect because the lymphatic system is not responsible for transporting oxygen (A), producing red blood cells (C), or regulating body temperature (D).