ati teas 7 science

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.

Correct Answer: B

Rationale: The correct answer is B: Atom. An atom is the smallest unit of matter that retains the properties of an element. Atoms are made up of protons, neutrons, and electrons. A molecule (A) consists of two or more atoms bonded together. A compound (C) is a substance composed of two or more different elements chemically bonded. An element (D) is a pure substance made up of only one type of atom. Therefore, the smallest unit of matter is the atom.

Correct Answer: C

Rationale: Destructive interference occurs when two waves meet and their amplitudes are out of phase, leading to the waves cancelling each other out. This results in a reduction or complete elimination of the wave's intensity at that point. Refraction (A) is the bending of waves due to a change in medium. Diffraction (B) is the bending of waves around obstacles. Constructive interference (D) occurs when two waves align their amplitudes and reinforce each other.

Correct Answer: C

Rationale: Gold (C) is the correct answer because it is highly malleable and does not tarnish. Gold is a popular choice for jewelry due to its durability and resistance to corrosion. Iron (A) is not commonly used in jewelry due to its susceptibility to rust. Copper (B) is malleable but prone to tarnishing. Silver (D) is malleable but can tarnish over time, making it less ideal for long-lasting jewelry pieces.

Correct Answer: B

Rationale: The adrenal glands are responsible for secreting adrenaline and cortisol in response to stress, triggering the fight-or-flight response. Adrenaline increases heart rate and blood flow, while cortisol releases energy stores. The pancreas regulates blood sugar, the thyroid gland controls metabolism, and the pituitary gland regulates hormone production but are not directly involved in the fight-or-flight response.