TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: Meiosis Prophase I. Crossing over occurs during Prophase I of meiosis, specifically during the substage called pachytene. This is when homologous chromosomes pair up and exchange genetic material. This process creates genetic diversity among offspring. Choice A, Mitosis Prophase, is incorrect because crossing over does not occur during mitosis, as homologous chromosomes do not pair up in mitosis. Choice C, Meiosis Prophase II, is incorrect because crossing over only occurs during Prophase I, not Prophase II. Choice D, Interphase, is incorrect because crossing over does not occur during interphase, as it is a phase where the cell prepares for division and DNA replication occurs.

Correct Answer: B

Rationale: The correct answer is B: To secrete digestive enzymes. The pancreas secretes enzymes such as amylase, lipase, and protease that aid in breaking down carbohydrates, fats, and proteins in the small intestine. This process is crucial for proper digestion and absorption of nutrients. Choice A is incorrect because the pancreas does not secrete bile, which is produced by the liver. Choice C is incorrect because the absorption of nutrients primarily occurs in the small intestine, not the pancreas. Choice D is incorrect as waste transportation is mainly handled by the intestines and kidneys, not the pancreas.

Correct Answer: B

Rationale: The correct answer is B: Parathyroid hormone. PTH is produced by the parathyroid glands and plays a crucial role in regulating calcium levels in the blood. It increases calcium levels by stimulating the release of calcium from bones, enhancing calcium absorption in the intestines, and reducing calcium excretion in the kidneys. Insulin (A) regulates blood sugar levels, not calcium. Thyroid hormone (C) controls metabolism, not calcium levels. Glucagon (D) increases blood sugar levels, not calcium.

Correct Answer: A

Rationale: The independent variable is what the researcher manipulates to observe its effect on the dependent variable. In this study, the botanist is testing if temperature affects root growth. Therefore, the independent variable is temperature (choice A). The botanist will change the temperature levels to see how it influences root growth. Choices B, C, and D are not the independent variable as the botanist is not directly manipulating seedlings, light, or root length to study the effect on root growth.

Correct Answer: B

Rationale: The correct answer is B: Somatic. The somatic nervous system controls voluntary movements by sending signals from the brain to skeletal muscles. It is under conscious control. Autonomic (A), sympathetic (C), and parasympathetic (D) systems control involuntary functions like heart rate and digestion. These systems operate without conscious effort, making them unsuitable for controlling voluntary movements.