ati teas 7 science

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: A

Rationale: The correct answer is A: Iron (Fe). This is because an element with atomic number 26 corresponds to Iron on the periodic table. The mass number of 56 indicates the total number of protons and neutrons in the nucleus of the atom, which is consistent with the atomic mass of Iron. Choice B, Cobalt, has an atomic number of 27, not 26. Choice C, Nickel, has an atomic number of 28, not 26. Choice D, Manganese, has an atomic number of 25, not 26. Therefore, based on the given atomic number and mass number, Iron is the most likely element.

Correct Answer: B

Rationale: Step 1: Active immunity involves the body's immune response, meaning the body produces its own antibodies after exposure to a pathogen. Step 2: Passive immunity provides immediate protection through antibodies from an external source, such as maternal antibodies or antibody injections. Step 3: The key difference lies in the origin of the antibodies - body's own immune response (active) vs. external antibodies (passive). Step 4: Choice B correctly identifies this distinction, making it the correct answer. Summary: Choices A, C, and D are incorrect as they do not accurately differentiate between active and passive immunity and provide misleading information about the duration, protection spectrum, and vaccination requirements.

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: B

Rationale: The correct answer is B: To secrete digestive enzymes. The pancreas secretes enzymes such as amylase, lipase, and proteases that help break down carbohydrates, fats, and proteins in the small intestine. This aids in the digestion and absorption of nutrients. Storing bile (A) is the role of the gallbladder, digesting proteins (C) is primarily done by the stomach and small intestine, and absorbing nutrients (D) mainly occurs in the small intestine.