ATI TEAS 7 Science

Correct Answer: D

Rationale: The correct answer is D: Pancreas. The pancreas produces insulin and glucagon, which are hormones involved in regulating blood sugar levels. Insulin helps lower blood sugar levels, while glucagon helps raise them. The salivary glands (A) produce saliva for digestion, the liver (B) plays a role in metabolism and detoxification, and the gallbladder (C) stores and releases bile to aid in digestion. Therefore, the pancreas is the correct organ responsible for producing insulin and glucagon.

Correct Answer: C

Rationale: The correct answer is C: Light energy from the sun. This is because photosynthesis, the process by which plants and other organisms convert light energy into chemical energy, is the primary source of energy in most ecosystems. Sunlight is essential for plants to produce food, which then sustains the entire food chain. Choice A (Chemical energy stored in bonds) is incorrect because this energy is a product of photosynthesis and not the primary source entering ecosystems. Choice B (Thermal energy from the Earth's core) is incorrect as it is not a significant source of energy for most ecosystems. Choice D (Kinetic energy from wind and water) is also incorrect as it is not the primary source of energy entering ecosystems, although it can play a role in some ecosystems.

Correct Answer: A

Rationale: The correct answer is A: Stapes. The stapes is the smallest bone in the human body, located in the middle ear. It plays a crucial role in transmitting sound vibrations to the inner ear. The other choices are incorrect because the patella is a knee bone, phalanges are finger bones, and ribs are chest bones, none of which are the smallest bone in the body. The stapes' small size and specific location make it uniquely suited for its function in hearing.

Correct Answer: D

Rationale: Apocrine and eccrine are types of sweat glands in the human body. Apocrine glands are found in areas like the armpits and groin, while eccrine glands are distributed throughout the skin. These glands play a crucial role in regulating body temperature through sweat production. Therefore, the correct answer is D: Sweat glands. A: Blood vessel - Incorrect. Apocrine and eccrine are not blood vessels. B: Cell types - Incorrect. Apocrine and eccrine are not cell types. C: Hormones - Incorrect. Apocrine and eccrine are not hormones.

Correct Answer: C

Rationale: The correct answer is C: Control sleep-wake cycles. Melatonin is primarily responsible for regulating our sleep-wake cycles, also known as the circadian rhythm. This hormone is released by the pineal gland in response to darkness, signaling to the body that it is time to sleep. Melatonin helps to synchronize our internal body clock with the natural day-night cycle. Choice A (Regulate blood pressure) is incorrect because melatonin does not play a direct role in regulating blood pressure. Choice B (Stimulate the digestive system) is incorrect as melatonin is not involved in stimulating the digestive system. Choice D (Maintain bone density) is also incorrect as melatonin's primary function is not related to bone density regulation.