ATI TEAS 7 Science

Correct Answer: D

Rationale: Certainly! The correct answer is D because saltatory conduction is faster than normal nerve conduction (A), occurs from one node of Ranvier to the next (B), and only occurs in myelinated neurons (C). This process involves the rapid transmission of action potentials in myelinated axons, where the impulse "jumps" from one node of Ranvier to the next, skipping the myelinated regions in between. This allows for faster conduction speeds compared to continuous conduction in unmyelinated neurons. Therefore, all of the statements in options A, B, and C are accurate descriptions of saltatory conduction, making option D the correct choice.

Correct Answer: B

Rationale: The correct answer is B: Skeletal. Skeletal muscles are responsible for voluntary movements because they are attached to bones and are under conscious control. They enable us to move our body parts intentionally. Smooth muscles (A) are involuntary and found in internal organs. Cardiac muscles (C) are also involuntary and specific to the heart. Option D simply defines a term and is not a type of muscle.

Correct Answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. This is the protective fluid that surrounds the brain and spinal cord. It acts as a cushion, providing mechanical protection, and helps to maintain a stable environment for the central nervous system. Blood (A) does not directly surround the brain and spinal cord. Myelin sheath (C) is a protective covering of nerve fibers, not the fluid surrounding the brain and spinal cord. Insulin (D) is a hormone involved in regulating blood sugar levels and is not the fluid that protects the brain and spinal cord.

Correct Answer: A

Rationale: The correct answer is A: Iron (Fe). This is because an element with atomic number 26 corresponds to Iron on the periodic table. The mass number of 56 indicates the total number of protons and neutrons in the nucleus of the atom, which is consistent with the atomic mass of Iron. Choice B, Cobalt, has an atomic number of 27, not 26. Choice C, Nickel, has an atomic number of 28, not 26. Choice D, Manganese, has an atomic number of 25, not 26. Therefore, based on the given atomic number and mass number, Iron is the most likely element.

Correct Answer: A

Rationale: The correct answer is A because polygenic inheritance refers to a trait that is influenced by multiple genes working together to produce a single phenotype. In contrast, pleiotropy occurs when a single gene has multiple effects on different traits. This distinction is crucial as it highlights the difference in the genetic basis of these phenomena. The other choices are incorrect because they either misinterpret the definitions of polygenic inheritance and pleiotropy (B and C) or provide vague statements without accurately distinguishing between the two concepts (D). The key to selecting the correct answer lies in understanding the fundamental genetic mechanisms underlying polygenic inheritance and pleiotropy.