ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: Thyroxine. Thyroxine is a hormone produced by the thyroid gland that plays a key role in regulating metabolism. It controls the body's metabolic rate, impacting energy levels and weight. Adrenaline (A) is produced by the adrenal glands and is involved in the fight-or-flight response. Cortisol (C) is produced by the adrenal glands and is known as the stress hormone. Insulin (D) is produced by the pancreas and regulates blood sugar levels, not metabolism. Thyroxine directly influences metabolism, making it the correct choice.

Correct Answer: A

Rationale: The primary function of the digestive system is to break down food into nutrients for absorption by the body. This process involves mechanical and chemical digestion to convert food into molecules that can be absorbed by the intestines. Option A is correct as it describes this essential function. Option B is incorrect because the absorption of oxygen primarily occurs in the respiratory system. Option C is incorrect as the production of energy is mainly attributed to the metabolic processes within cells. Option D is incorrect as the regulation of body temperature is primarily controlled by the thermoregulatory system, not the digestive system.

Correct Answer: B

Rationale: The correct answer is B. A decomposition reaction involves a single compound breaking down into two or more simpler substances. In choice B, CaCO3 decomposes into CaO and CO2. This reaction follows the general form AB → A + B, making it a clear example of a decomposition reaction. Choices A, C, and D involve synthesis or combination reactions, where simpler substances combine to form a more complex compound, making them incorrect for this question.

Correct Answer: C

Rationale: The correct answer is C: Testosterone. Testosterone is crucial for stimulating sperm production in males as it is the primary male sex hormone responsible for regulating the development of male reproductive tissues. It plays a key role in the production of sperm cells in the testes. Estrogen (A) and Progesterone (B) are female sex hormones and do not have a direct role in sperm production. Insulin (D) is a hormone that regulates blood sugar levels and is not involved in the process of sperm production.

Correct Answer: C

Rationale: The correct answer is C: Carries specific amino acids to the ribosomes. tRNA is responsible for carrying specific amino acids to the ribosomes during protein synthesis. It recognizes the codons on mRNA and pairs them with the corresponding amino acids. This process ensures that the correct amino acids are added to the growing polypeptide chain. Choice A is incorrect because tRNA does not transcribe DNA into mRNA; that is the role of RNA polymerase. Choice B is incorrect because decoding the genetic code on mRNA is done by tRNA along with the ribosomes. Choice D is incorrect because tRNA does not modify the structure of proteins; that is typically done by enzymes or post-translational modifications.