TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: Pancreas. The pancreas is responsible for producing insulin because it contains clusters of cells called islets of Langerhans, specifically beta cells, which secrete insulin. The liver (A) plays a role in regulating blood sugar levels but does not produce insulin. The gallbladder (C) stores bile and aids in digestion, not insulin production. The spleen (D) is important for immune function but does not produce insulin. Therefore, the pancreas is the correct choice for producing insulin.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver is responsible for filtering toxins from the blood through a process called detoxification. It metabolizes and eliminates toxins, drugs, and alcohol from the bloodstream. The kidneys (A) filter waste from the blood but do not primarily handle toxins. The heart (C) pumps blood and does not have a filtration function. The lungs (D) exchange gases and do not filter toxins from the blood. Therefore, the liver is the correct answer for filtering toxins from the blood.

Correct Answer: A

Rationale: The correct answer is A: Helicase. Helicase is responsible for unwinding the double-stranded DNA during replication by breaking the hydrogen bonds between the base pairs. This allows the DNA strands to separate and serve as templates for the synthesis of new DNA strands by DNA polymerase. Ligase is responsible for joining the DNA fragments together, nuclease is involved in DNA repair by cutting out damaged DNA, and polymerase is responsible for synthesizing new DNA strands based on the template strands. Therefore, only helicase directly unwinds the double-stranded DNA during replication.

Correct Answer: C

Rationale: The correct answer is C: Inner mitochondrial membrane. The electron transport chain occurs in the inner mitochondrial membrane because it is where the proteins and complexes involved in oxidative phosphorylation are located. This is where electrons are passed along the chain, leading to the production of ATP. The cytosol (choice A) is where glycolysis occurs, not the electron transport chain. The Golgi apparatus (choice B) is involved in protein processing and sorting, not energy production. The nucleus (choice D) houses the cell's genetic material and is not directly involved in the electron transport chain.

Correct Answer: B

Rationale: The correct answer is B: Cerebellum. The cerebellum is responsible for coordinating muscle movements by receiving information from the sensory systems, spinal cord, and other parts of the brain to regulate motor movements. It plays a crucial role in maintaining balance, posture, and smooth coordination of voluntary movements. The other choices are incorrect because: A: The cerebrum is primarily involved in higher brain functions such as thinking, decision-making, and emotions. C: The thalamus acts as a relay station for sensory information but does not directly control muscle coordination. D: The medulla oblongata is responsible for regulating vital functions such as breathing, heart rate, and blood pressure, but not specifically muscle coordination.