ATI TEAS 7 Science

Correct Answer: C

Rationale: The correct answer is C: To regulate body functions through hormones. The endocrine system consists of glands that produce hormones to regulate various bodily functions like metabolism, growth, and reproduction. This system helps maintain homeostasis by communicating through chemical messengers. Choices A, B, and D are incorrect as fighting infection is primarily the role of the immune system, oxygen transportation is done by the respiratory system, and food breakdown is the function of the digestive system.

Correct Answer: C

Rationale: The correct answer is C: Small intestine. The small intestine is the primary site for nutrient absorption in the digestive system due to its large surface area, specialized structures called villi, and microvilli that maximize absorption efficiency. Digestive enzymes and bile are also released in the small intestine to break down nutrients for absorption. The other choices are incorrect because the esophagus is responsible for swallowing, the large intestine mainly absorbs water and electrolytes, and the stomach primarily functions in digestion by secreting gastric juices.

Correct Answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are responsible for maintaining electrolyte balance through processes like reabsorption and excretion. They also filter waste from the blood to form urine. The liver primarily processes nutrients and detoxifies substances. The heart is responsible for pumping blood, not filtering waste. The lungs are involved in gas exchange, not electrolyte balance or waste filtration. Therefore, the kidneys are the correct choice for this function.

Correct Answer: A

Rationale: The main function of lysosomes is to break down and recycle cellular waste through the process of autophagy. Lysosomes contain enzymes that break down various molecules, organelles, and pathogens. This process helps maintain cellular homeostasis and provides the cell with raw materials for new cell components. Storing carbohydrates (B) is incorrect as lysosomes do not function in this capacity. Synthesizing lipids (C) is incorrect as this is typically the role of the endoplasmic reticulum and Golgi apparatus. Transcribing DNA into mRNA (D) is incorrect as this process occurs in the nucleus by RNA polymerase.

Correct Answer: D

Rationale: The correct answer is D: tRNA. Transfer RNA (tRNA) carries amino acids to ribosomes during protein synthesis. tRNA has an anticodon that pairs with the mRNA codon, ensuring the correct amino acid is added to the growing polypeptide chain. A: DNA carries genetic information but does not directly participate in protein synthesis. B: mRNA carries the genetic information from DNA to the ribosomes but does not carry amino acids. C: rRNA is a structural component of ribosomes and helps in protein synthesis but does not carry amino acids to the ribosomes.