TEAS 7 practice test free science

Correct Answer: D

Rationale: Nuclear fission is the correct answer. It is the process in which a large, unstable nucleus splits into two smaller nuclei, releasing neutrons and energy. Alpha decay, beta decay, and gamma decay involve the emission of alpha particles, beta particles, and gamma rays, respectively. These decay processes do not result in the splitting of a nucleus like nuclear fission does.

Correct Answer: A

Rationale: Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. This double bond is a key characteristic that distinguishes alkenes from other types of hydrocarbons. Option A correctly identifies this defining feature of alkenes, making it the correct answer. Choices B, C, and D are incorrect. Choice B is incorrect because alkenes are unsaturated hydrocarbons due to the presence of double bonds. Choice C is incorrect as alkenes do not contain only single bonds; they have at least one double bond. Choice D is incorrect because alkenes are not derivatives of ammonia; they are a distinct class of organic compounds with carbon-carbon double bonds.

Correct Answer: D

Rationale: Understanding atomic structure is essential for various technological advancements. Designing new materials with tailored properties necessitates knowledge of atomic structure to effectively manipulate their characteristics. Developing advanced electronics and nanotechnology involves working at the atomic level to create smaller, faster, and more efficient devices. Improving nuclear energy production and safety also heavily depends on understanding atomic structure to enhance reactor design and safety measures. Therefore, all the options provided (A, B, and C) are potential applications of understanding atomic structure in modern technology.

Correct Answer: B

Rationale: The correct answer is the Cardiac sphincter (lower esophageal sphincter). It is situated at the junction of the esophagus and the stomach, controlling the passage of food into the stomach. The cardiac sphincter opens and closes to regulate the flow of food and prevent reflux. The pyloric sphincter, on the other hand, is located between the stomach and the small intestine, not the esophagus and stomach. The ileocecal valve is positioned between the small and large intestines, while the Sphincter of Oddi is found in the duodenum, not between the esophagus and stomach.

Correct Answer: A

Rationale: Deamination is the correct answer. It is the process of removing an amino group from a molecule, like converting ammonia (NH3) into a less toxic form such as urea. Ammonia, a byproduct of protein digestion, must be converted into a less toxic form for excretion. Deamination is a crucial step that mainly occurs in the liver through the urea cycle. Transamination involves transferring an amino group from one molecule to another, not removing it as in deamination. Decarboxylation is the removal of a carboxyl group from a molecule, and hydrolysis is the breakdown of a compound by adding water.