ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver is responsible for detoxifying chemicals and metabolizing drugs due to its enzymes that break down substances. It also helps in excreting waste products. The kidneys (A) filter blood and regulate fluid balance. The heart (C) pumps blood throughout the body. The pancreas (D) produces digestive enzymes and insulin. Thus, the liver is the primary organ involved in detoxification and drug metabolism.

Correct Answer: A

Rationale: The correct answer is A: Covalent bond. In a covalent bond, atoms share electrons to achieve a stable electron configuration. This sharing allows both atoms to fill their outer electron shells and form a strong bond. Ionic bonds (choice B) involve the transfer of electrons, not sharing. Metallic bonds (choice C) occur in metals where electrons are delocalized. Hydrogen bonds (choice D) are weak electrostatic attractions between hydrogen and electronegative atoms, not a result of electron sharing. Thus, the correct answer is A because it accurately describes the sharing of electrons between elements to form a covalent bond.

Correct Answer: B

Rationale: The correct answer is B: It runs 3' to 5'. The antisense strand of DNA runs in the opposite direction to the sense strand. This is essential for complementary base pairing during transcription. The 3' to 5' direction allows RNA polymerase to synthesize RNA in the 5' to 3' direction, following the template of the antisense strand. Therefore, choice B is correct. Choices A and C are incorrect because the directionality of the antisense strand is opposite to 5' to 3' and it is used in transcription, not replication. Choice D is incorrect as DNA is stored in the cell nucleus in a double helix structure, not in a specific direction.

Correct Answer: D

Rationale: The main function of the lungs is to exchange oxygen and carbon dioxide between the body and the environment. This process, known as respiration, is essential for cellular function. Step 1: Oxygen is inhaled into the lungs and diffuses into the bloodstream. Step 2: Carbon dioxide produced by cells is carried to the lungs via the bloodstream and exhaled. Choice A is incorrect as the primary function of the lungs is gas exchange, not nutrient transport. Choice B is incorrect as movement coordination is a function of the nervous system. Choice C is incorrect as waste filtration is primarily done by the kidneys and liver.

Correct Answer: A

Rationale: The correct answer is A: Penicillins. Penicillins target the cell wall of bacteria by inhibiting the synthesis of peptidoglycan, a crucial component of the bacterial cell wall. This disrupts the integrity of the cell wall, leading to bacterial cell lysis. Tetracyclines (B), Macrolides (C), and Fluoroquinolones (D) target different bacterial components like protein synthesis or DNA replication, making them incorrect choices for this question.