ATI TEAS 7 Science

Correct Answer: C

Rationale: The correct answer is C: GABA. GABA is an inhibitory neurotransmitter that slows down neuron activity by binding to GABA receptors, leading to hyperpolarization of the neuron and reducing the likelihood of firing an action potential. This process helps to prevent overexcitation in the nervous system. A: Acetylcholine is primarily an excitatory neurotransmitter involved in muscle control and cognitive function. B: Dopamine plays a role in reward-motivated behavior and movement, but it is not primarily responsible for slowing down neuron activity. D: Serotonin is involved in regulating mood, appetite, and sleep, but it does not directly slow down neuron activity to prevent overexcitation.

Correct Answer: C

Rationale: Destructive interference occurs when two waves meet and their amplitudes are out of phase, leading to the waves cancelling each other out. This results in a reduction or complete elimination of the wave's intensity at that point. Refraction (A) is the bending of waves due to a change in medium. Diffraction (B) is the bending of waves around obstacles. Constructive interference (D) occurs when two waves align their amplitudes and reinforce each other.

Correct Answer: A

Rationale: The correct answer is A: Hypothalamus. The hypothalamus plays a vital role in regulating body temperature by responding to internal and external temperature changes. It coordinates the body's response to maintain a stable temperature through processes like sweating or shivering. B: Cerebellum is responsible for coordinating movement and balance, not body temperature regulation. C: Pituitary gland regulates hormone production but not directly involved in body temperature regulation. D: Thyroid gland controls metabolism and energy levels but not primarily responsible for regulating body temperature.

Correct Answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle is found exclusively in the heart, allowing it to contract rhythmically and involuntarily to pump blood throughout the body. Smooth muscle (A) is found in organs like the intestines and blood vessels, not in the heart. Skeletal muscle (C) is attached to bones and responsible for voluntary movements, while voluntary muscle (D) is a general term that refers to skeletal muscle controlled voluntarily. Therefore, the unique characteristics of cardiac muscle make it the correct answer for this question.

Correct Answer: C

Rationale: The correct answer is C: Phagocytes. Phagocytes are white blood cells responsible for the initial attack on pathogens by engulfing and digesting them. They include neutrophils, monocytes, and macrophages. Red blood cells (A) are not involved in the immune response. Platelets (B) are responsible for blood clotting, not attacking pathogens. Lymphocytes (D) play a role in specific immune responses but are not the primary cells responsible for the initial attack on pathogens.