ATI TEAS 7 science review

Correct Answer: C

Rationale: Oligodendrocytes are a type of glial cell that provides structural support and insulation for neurons in the central nervous system by forming myelin sheaths around axons. Schwann cells (option A) perform a similar function but in the peripheral nervous system. Astrocytes (option B) are involved in providing nutrients to neurons, maintaining the chemical environment, and repairing damage. Microglia (option D) are primarily responsible for immune defense in the central nervous system, not for providing structural support and insulation for neurons.

Correct Answer: C

Rationale: A) Binomial nomenclature is a system used to give each organism a two-part scientific name (genus and species) but does not help in identifying or classifying organisms based on shared characteristics. B) Cladistics is a method of classification based on evolutionary relationships and shared characteristics, but it is not a tool used for identifying organisms. C) A dichotomous key is a tool that helps scientists identify and classify organisms based on their shared characteristics by presenting a series of choices leading the user to the correct identification. D) Domain-based classification is a system of grouping organisms into three domains (Bacteria, Archaea, Eukarya) based on molecular and genetic similarities, but it is not a tool used for identifying organisms based on shared characteristics.

Correct Answer: A

Rationale: In the given reaction, the complete ionic equation is: 2H+(aq) + 2Cl-(aq) + Ba2+(aq) + 2OH-(aq) → 2H2O(l) + Ba2+(aq) + 2Cl-(aq). Spectator ions (Ba2+ and Cl-) do not participate in the net ionic equation, which simplifies to: 2H+(aq) + 2OH-(aq) → 2H2O(l). This equation represents the significant species involved in the reaction, showcasing the formation of water from the combination of hydrogen ions and hydroxide ions, resulting in the production of water molecules.

Correct Answer: C

Rationale: Amylase is the enzyme responsible for breaking down carbohydrates in the small intestine. It specifically targets starches and sugars, breaking them down into smaller molecules like maltose and glucose that can be absorbed by the body. Pepsin is an enzyme that breaks down proteins in the stomach, not the small intestine. Lipase is responsible for breaking down fats, not carbohydrates. Trypsin is an enzyme that breaks down proteins in the small intestine, not carbohydrates.

Correct Answer: B

Rationale: Fusion is the process by which lighter nuclei combine to form heavier nuclei, releasing a large amount of energy in the process. This process is the source of energy in stars, including our Sun. Fission, the process of splitting heavier nuclei into lighter nuclei, is not correct. Radioactivity involves the emission of particles or radiation from the nucleus of an unstable atom, which is different from fusion. A chain reaction is a self-sustaining reaction where the products of one reaction cause further reactions, which is unrelated to fusion.