ATI TEAS Science

Correct Answer: C

Rationale: The correct answer is C (3). In a typical sensory pathway, there are three neurons involved: the primary sensory neuron, secondary sensory neuron, and tertiary sensory neuron. The primary sensory neuron transmits signals from the sensory receptor to the spinal cord or brainstem. The secondary sensory neuron carries the signal from the spinal cord or brainstem to the thalamus in the brain. Lastly, the tertiary sensory neuron carries the signal from the thalamus to the sensory cortex for processing. Therefore, a sensory pathway typically comprises three neurons to relay sensory information from the periphery to the brain. Choice A (1) is incorrect because sensory pathways involve multiple neurons for signal transmission. Choice B (2) is incorrect as it does not account for the tertiary sensory neuron involved in the pathway. Choice D (4) is incorrect because the typical sensory pathway consists of three neurons, not four.

Correct Answer: A

Rationale: The correct answer is A because all types of muscle tissue share the properties of being contractile (ability to contract), excitable (responsive to stimuli), elastic (ability to return to original shape), and extensible (ability to stretch). Choice B is incorrect because voluntary is not a shared property of all muscle tissues. Choice C is incorrect because voluntary is not a shared property of all muscle tissues. Choice D is incorrect because voluntary is not a shared property of all muscle tissues.

Correct Answer: D

Rationale: The correct answer is D because organisms maintain homeostasis by using free energy and matter to counteract entropy. This is achieved through various biochemical processes that regulate internal conditions within a narrow range to ensure stability. By utilizing energy and matter efficiently, organisms can balance their internal environment despite external fluctuations. Choice A is incorrect because increasing body temperature, blood pH, and fluid balance do not necessarily maintain homeostasis but rather reflect changes in the internal environment. Choice B is incorrect as absorbing energy to increase entropy would disrupt homeostasis rather than maintain it. Choice C is incorrect because maintaining the order of the external environment is not directly related to the internal balance required for homeostasis.

Correct Answer: D

Rationale: The correct answer is D because the autonomic nervous system (ANS) indeed contains both parasympathetic and sympathetic nerves. The ANS regulates involuntary functions such as heart rate, digestion, and respiratory rate. A: While A is partially correct, it does not encompass the full scope of the ANS functions. B: B is incorrect as the ANS primarily consists of efferent neurons that carry motor signals from the central nervous system to target organs. C: C is incorrect as the ANS consists of efferent neurons that carry signals away from the central nervous system to target organs, not sensory neurons.

Correct Answer: A

Rationale: To represent 8,600,000,000,000 in scientific notation with two significant figures, we need to move the decimal point to have one non-zero digit before it. Step 1: Write the number in scientific notation: 8.6 x 10^12 Step 2: Check the significant figures: 8.6 has two significant figures. Step 3: Ensure the exponent matches the number of zeros in the original number. Rationale: Choice A is correct as it follows the rules for converting a number to scientific notation with two significant figures. Choices B, C, and D are incorrect because they do not correctly represent the original number in scientific notation with two significant figures. Choice B has the incorrect sign for the exponent, choice C has the incorrect exponent value, and choice D has an unnecessary zero after the decimal point.