Practice TEAS Science Test

Correct Answer: B

Rationale: The correct answer is B: ATP energy. Cellular respiration is the process by which cells convert glucose into ATP, the primary energy source for cellular activities. During cellular respiration, glucose is broken down in the presence of oxygen to produce ATP through a series of metabolic reactions. Oxygen (choice A) is required for cellular respiration but is not an end product. Carbon dioxide (choice C) is a byproduct of cellular respiration, not an end product. Water (choice D) is not directly produced as an end product of cellular respiration. Thus, choice B is the correct answer as ATP energy is the main end product generated from cellular respiration.

Correct Answer: B

Rationale: The correct answer is B: Medulla oblongata. This part of the brain is located in the brainstem and is responsible for controlling vital involuntary functions like breathing, heart rate, and blood pressure. It contains nuclei that regulate these activities and plays a crucial role in maintaining homeostasis. The cerebellum (A) is involved in coordinating movement and balance, the cerebrum (C) is responsible for higher brain functions like thinking and decision-making, and the thalamus (D) acts as a relay center for sensory information. However, they are not directly involved in controlling involuntary actions like breathing and heart rate.

Correct Answer: B

Rationale: The correct answer is B: Jejunum. The jejunum is the primary site of absorption in the small intestine due to its extensive surface area, presence of villi and microvilli that increase absorption capacity, and higher blood supply compared to other regions. It is where most nutrients such as carbohydrates, proteins, and fats are absorbed. The duodenum (A) is mainly responsible for initial digestion, the ileum (C) absorbs bile salts, vitamin B12, and some nutrients, and the cecum (D) is part of the large intestine and is not involved in nutrient absorption.

Correct Answer: C

Rationale: The correct answer is C: Humerus. The humerus is the long bone found in the upper arm. It connects the shoulder to the elbow joint. The femur (A) is the long bone found in the thigh, the tibia (B) is the larger of the two lower leg bones, and the radius (D) is one of the two lower arm bones. The humerus is the only bone among the choices that is specifically located in the upper arm, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Thyroxine. Thyroxine is produced by the thyroid gland and plays a crucial role in regulating the body's metabolism by controlling the rate at which cells use energy. Insulin is a hormone that regulates blood sugar levels, not metabolism. Melatonin is responsible for regulating sleep-wake cycles, not metabolism. Adrenaline, also known as epinephrine, is involved in the fight or flight response and does not directly regulate metabolism.