TEAS 7 Science Practice Test

Correct Answer: A

Rationale: The primary function of the pyloric sphincter is to regulate the movement of food material from the stomach to the duodenum. This is crucial for proper digestion as it controls the release of partially digested food into the small intestine for further processing. Choices B and D are incorrect because the pyloric sphincter does not neutralize stomach acid or begin the process of chemical digestion; those functions are carried out by other parts of the digestive system. Choice C is incorrect as preventing digested food materials and stomach acid from entering the esophagus is the primary role of the lower esophageal sphincter, not the pyloric sphincter.

Correct Answer: D

Rationale: The correct answer is D: Combustion reaction. In a combustion reaction, a compound reacts with oxygen gas to produce carbon dioxide and water. In this equation, 2C₆H₁₄ (hexane) reacts with 19O₂ to produce 12CO (carbon monoxide) and 14H₂O (water). This reaction is characteristic of combustion, where a fuel (hexane) reacts with oxygen to release energy in the form of heat and light. Summary: A: Substitution reaction involves replacing one element or group in a compound with another element or group. This is not demonstrated in the given equation. B: Acid-base reaction involves the transfer of protons between substances. There are no acids or bases involved in the given equation. C: Enzyme reaction involves the catalysis of a chemical reaction by an enzyme. Enzymes are not mentioned in the given equation.

Correct Answer: B

Rationale: The correct answer is B: medulla oblongata. This region of the brain is responsible for controlling and regulating autonomic functions like respiration, digestion, and heart rate. It is located in the brainstem and contains vital centers for these functions. The cerebellum (A) is primarily involved in coordination and balance. The temporal lobe (C) is responsible for auditory processing and memory. The cerebral cortex (D) is involved in higher cognitive functions like thinking and decision-making. Therefore, the medulla oblongata is the correct choice as it specifically controls autonomic functions.

Correct Answer: C

Rationale: The correct answer is C, the law of independent assortment. This law states that alleles for different traits segregate independently of each other during gamete formation. This is due to the random alignment of homologous chromosomes during meiosis. The law of segregation (A) describes how alleles of a gene separate during gamete formation. The law of dominance (B) explains that one allele can mask the expression of another in heterozygous individuals. The law of predictive traits (D) is not a recognized Mendelian law and is therefore incorrect. In summary, the law of independent assortment best describes how alleles from different genes segregate independently during gamete formation.

Correct Answer: C

Rationale: The correct answer is C: lipids. Lipids are non-soluble in water due to their hydrophobic nature. They are composed of hydrocarbons, such as fatty acids, which provide a concentrated source of energy storage in the body. Carbohydrates (choice A) are soluble and primarily serve as a quick energy source. Nucleic acids (choice B) are involved in genetic information storage and transfer. Proteins (choice D) are made up of amino acids and have various functions in the body, but they are not typically used for energy storage. Therefore, lipids are the only option that fits all the criteria given in the question.