ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B because it demonstrates a single displacement reaction where zinc (Zn) displaces hydrogen (H) in hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). This is evident from the activity series where Zn is more reactive than H. A, C, and D are not examples of single displacement reactions. A represents a synthesis reaction where hydrogen and oxygen combine to form water. C represents a decomposition reaction where calcium carbonate breaks down into calcium oxide and carbon dioxide. D represents a combustion reaction where methane reacts with oxygen to form carbon dioxide and water.

Correct Answer: C

Rationale: The correct answer is C, the Combined oral contraceptive pill. This method uses hormones like estrogen and progestin to prevent ovulation. Firstly, estrogen suppresses follicle-stimulating hormone (FSH) production, inhibiting follicular development. Secondly, progestin thickens cervical mucus, preventing sperm penetration. Lastly, progestin also inhibits luteinizing hormone (LH) surge, preventing ovulation. Spermicide (A) works by killing sperm but does not prevent ovulation. Barrier methods (B) like condoms and diaphragms physically block sperm from reaching the egg but do not affect ovulation. Intrauterine devices (IUDs) (D) work by preventing sperm from fertilizing the egg or by altering the uterine lining, but they do not directly prevent ovulation.

Correct Answer: B

Rationale: The correct answer is B because "survival of the fittest" refers to the idea that organisms with the best adaptations to their environment are more likely to survive and reproduce, passing on their advantageous traits to the next generation. This concept, coined by Charles Darwin, emphasizes the importance of natural selection in driving evolution. Choice A is incorrect as complexity does not always equate to fitness. Choice C is incorrect as natural selection favors certain traits over others. Choice D is incorrect as survival and reproduction are not solely determined by strength and aggression.

Correct Answer: C

Rationale: Rationale: Cytosol is the liquid component of the cytoplasm and is not membrane-bound. Mitochondrion is a membrane-bound organelle responsible for energy production. Therefore, the difference between cytosol and mitochondrion is that the mitochondrion is a membrane-bound organelle, while cytosol is not. Summary: A: Incorrect. Cytosol is not a membrane-bound organelle, and the mitochondrion is also not membrane-bound. B: Incorrect. Cytosol is part of the cytoplasm, and the mitochondrion is also located within the cytoplasm. C: Correct. The mitochondrion is a membrane-bound organelle, while cytosol is not. D: Incorrect. Both the mitochondrion and cytosol are components of the cytoplasm, but the mitochondrion is membrane-bound, unlike cytosol.

Correct Answer: C

Rationale: The correct answer is C: Exceptional stability of the nucleus. Magic numbers are specific numbers of protons or neutrons that result in a more stable nucleus due to the arrangement of nucleons in energy levels. This stability is a result of closed shells, leading to lower energy states and less tendency for decay. Choices A and B are incorrect as magic numbers actually contribute to increased stability, leading to decreased nuclear instability and lower radioactive decay rates. Choice D is incorrect because magic numbers do not lead to increased instability or enhanced decay rates, but rather to exceptional stability.