ati teas 7 science

Correct Answer: C

Rationale: Renin is the correct answer. Renin is an enzyme released by the kidneys in response to low blood pressure. It plays a key role in regulating blood pressure by initiating a series of reactions that ultimately lead to the constriction of blood vessels and retention of water and sodium. This helps to raise blood pressure back to normal levels. Insulin (choice A) is involved in regulating blood sugar levels, not blood pressure. Testosterone (choice B) and Estrogen (choice D) are sex hormones that do not have a direct impact on kidney function and blood pressure regulation.

Correct Answer: A

Rationale: The correct answer is A: Calcitonin. Calcitonin is produced by the thyroid gland and functions to lower blood calcium levels by promoting calcium deposition in bones and inhibiting calcium reabsorption in the kidneys. This hormone opposes the action of parathyroid hormone (PTH), which increases blood calcium levels by promoting calcium release from bones and increasing calcium reabsorption in the kidneys. Thyroxine is a thyroid hormone that regulates metabolism and growth, not calcium levels. Insulin is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels. Thus, A is the correct answer as it directly regulates calcium levels in the blood through its actions on bones and kidneys.

Correct Answer: B

Rationale: The correct answer is B: Bacteria. Dysentery is primarily caused by pathogenic bacteria such as Shigella or Escherichia coli. Bacteria are single-celled microorganisms that can infect the intestines and cause symptoms like bloody diarrhea and abdominal pain. Helminths are parasitic worms that typically cause different types of infections. Protozoa are single-celled organisms that can also cause intestinal infections, but they are not the primary cause of dysentery. Fungi do not typically cause dysentery; they are more commonly associated with skin infections or respiratory issues. In summary, the correct answer is B because dysentery is most commonly caused by bacterial infections in the intestines.

Correct Answer: D

Rationale: The correct answer is D: Researching previous studies for background. Before generating a hypothesis, it is crucial to review existing research to build a foundation of knowledge. This step helps identify gaps in current understanding, refine research questions, and ensure the hypothesis is based on existing evidence. Collecting and organizing data (A) occurs after the hypothesis is formulated. Communicating results (B) is the final step after conducting experiments (C). Therefore, the correct order is researching previous studies (D), generating a hypothesis, conducting an experiment, collecting and organizing data, and finally communicating the results.

Correct Answer: C

Rationale: The correct answer is C: Emulsify fats. Bile helps emulsify fats by breaking them down into smaller droplets, increasing the surface area for enzymes to digest fats. This aids in the absorption of fats and fat-soluble vitamins in the small intestine. Choice A is incorrect because bile does not break down carbohydrates. Choice B is incorrect as bile does not break down proteins. Choice D is incorrect because bile does not neutralize stomach acid; rather, it helps with fat digestion in the small intestine.