ATI TEAS 7 Science

Correct Answer: B

Rationale: The primary function of red blood cells is to transport oxygen. They contain hemoglobin, which binds to oxygen in the lungs and delivers it to tissues throughout the body. This process is essential for cellular respiration and energy production. Choice A is incorrect because while red blood cells do transport nutrients, their main role is oxygen transport. Choice C is incorrect because fighting infection is primarily the role of white blood cells. Choice D is incorrect as red blood cells do not produce antibodies; that is the function of specialized white blood cells called B cells.

Correct Answer: A

Rationale: The correct answer is A: Convergent evolution. Dinosaurs evolving feathers before birds supports convergent evolution because it shows unrelated organisms (dinosaurs and birds) developing similar traits (feathers) independently to adapt to similar environmental pressures. This scenario is not an example of divergent evolution (B) where related organisms evolve different traits. It also does not demonstrate coevolution (C) where two species influence each other's evolution. The extinction of dinosaurs due to an asteroid impact (D) is not directly related to the evolution of feathers in dinosaurs before birds.

Correct Answer: C

Rationale: The correct answer is C: Emulsify fats. Bile helps emulsify fats by breaking them down into smaller droplets, increasing the surface area for enzymes to digest fats. This aids in the absorption of fats and fat-soluble vitamins in the small intestine. Choice A is incorrect because bile does not break down carbohydrates. Choice B is incorrect as bile does not break down proteins. Choice D is incorrect because bile does not neutralize stomach acid; rather, it helps with fat digestion in the small intestine.

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: A

Rationale: The correct answer is A: Neuron. Neurons are specialized cells that transmit electrical impulses in the nervous system. They consist of a cell body, dendrites to receive signals, an axon to transmit signals, and synaptic terminals to communicate with other neurons. The axon is the long fiber that carries the electrical impulses away from the cell body. Myelin is a fatty substance that insulates and speeds up signal transmission along the axon. Dendrites receive signals from other neurons and transmit them towards the cell body. Therefore, the neuron is the fundamental structure responsible for transmitting electrical impulses, making it the correct answer.