ATI TEAS 7 Science - Nurselytic

Correct Answer: C

Rationale: Melatonin is primarily known for its role in controlling sleep-wake cycles. It is produced by the pineal gland in response to darkness, helping signal the body that it is time to sleep. Melatonin levels typically rise in the evening and stay elevated throughout the night, promoting sleep.

Choices A, B, and D are incorrect as melatonin's primary function is not to regulate blood pressure, stimulate the digestive system, or maintain bone density. While melatonin may have some indirect effects on these functions, its main role lies in regulating the circadian rhythm and promoting a restful sleep cycle.

Correct Answer: B

Rationale: The correct answer is B: Adrenal glands. The adrenal glands are responsible for the body's fight-or-flight response. During stressful situations, the adrenal glands release hormones like adrenaline and noradrenaline, initiating the fight-or-flight response. These hormones prepare the body to either confront or flee from a perceived threat.\n
Choice A - Pancreas: The pancreas is primarily responsible for producing insulin and regulating blood sugar levels, not the fight-or-flight response.\n
Choice C - Thyroid gland: The thyroid gland is responsible for producing hormones that regulate metabolism, not directly involved in the fight-or-flight response.\n
Choice D - Pituitary gland: The pituitary gland regulates various endocrine functions by releasing hormones, but it is not the primary gland responsible for the fight-or-flight response.

Correct Answer: B

Rationale: Gravitational potential energy is directly proportional to the height or distance from the ground. As the object is raised higher, its gravitational potential energy increases. While the mass of the object influences gravitational potential energy, the distance from the ground has a more significant impact on it. The gravitational force does not directly affect the gravitational potential energy; it is the force that causes the potential energy to change with height. The shape of the object also does not determine gravitational potential energy, as it is primarily determined by the object's position in a gravitational field.

Correct Answer: D

Rationale: The main obstacle to achieving controlled nuclear fusion on Earth for energy production involves a combination of factors.
A) Lack of suitable materials to handle high temperatures and pressures is a significant challenge due to the extreme conditions required for fusion reactions.
B) Limited availability of fusion fuels like deuterium and tritium can pose a constraint on the scalability and sustainability of fusion energy.
C) Difficulty in containing the plasma where fusion occurs is another critical issue as plasma instabilities and heat losses can hinder the efficiency of fusion reactions.
Therefore, all of the options (A, B, and
C) contribute to the challenges in achieving controlled nuclear fusion for energy production on Earth.

Correct Answer: B

Rationale: A balanced chemical equation must have the same number of atoms of each element on both sides of the equation. In option B, 2H2 + O2 → 2H2O, the equation is balanced as there are 2 hydrogen atoms and 2 oxygen atoms on both the reactant and product sides after balancing, satisfying the law of conservation of mass. Option A is unbalanced as there are 2 oxygen atoms on the reactant side but only 1 oxygen atom on the product side. Option C is unbalanced with 3 hydrogen atoms on the reactant side and 2 hydrogen atoms on the product side. Option D is unbalanced with 1 oxygen atom on the reactant side and 2 oxygen atoms on the product side.