ATI TEAS Science

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: The correct answer is A: A plasma membrane. Both prokaryotes and eukaryotes have a plasma membrane as their outer boundary. The plasma membrane is essential for maintaining cell integrity, controlling the passage of molecules in and out of the cell, and facilitating communication with the external environment. Prokaryotes lack a nucleus enclosed by a membrane (choice B), which is a defining feature of eukaryotic cells. Eukaryotes have organelles (choice C) that are membrane-bound structures, unlike prokaryotes that lack membrane-bound organelles. A nucleoid (choice D) is a region in prokaryotic cells where the genetic material is located, but it is not enclosed by a membrane like the nucleus in eukaryotic cells.

Correct Answer: B

Rationale: The correct answer is B: Secondary structure. Secondary structure is defined by the local folds and coils in the protein's polypeptide backbone, such as alpha helices and beta sheets. This level of structure does not involve interactions between different regions of the protein (tertiary) or multiple protein subunits (quaternary). Primary structure (A) refers to the linear sequence of amino acids. Tertiary structure (C) involves the 3D arrangement of secondary structures and other elements in a single polypeptide chain. Quaternary structure (D) pertains to the arrangement of multiple polypeptide subunits in a protein complex.

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: B

Rationale: The correct answer is B: The pelvic cavity. The pelvic cavity is located in the lower part of the trunk and houses the urinary bladder, urethra, and ureters. The thoracic cavity (A) contains the heart and lungs, the abdominal cavity (C) contains the stomach, liver, and intestines, and the spinal cavity (D) houses the spinal cord. Therefore, B is the correct answer as it specifically contains the organs mentioned in the question.