what types of cells myelinate neurons in the cns

ATI TEAS 7

ATI TEAS Science Practice Test

1. Which cells myelinate neurons in the CNS?

A. Schwann cells
B. Astrocytes
C. Microglia
D. Oligodendrocytes

Correct answer: D

Rationale: The correct answer is D, Oligodendrocytes. Oligodendrocytes are responsible for myelinating neurons in the central nervous system (CNS). Schwann cells, found in the peripheral nervous system, are responsible for myelinating neurons there. Astrocytes support and maintain the neuronal environment, while microglia function as immune cells in the CNS, participating in immune responses and cellular debris clearance. Therefore, choices A, B, and C are incorrect for myelination of CNS neurons.

2. Which version of the sentence does NOT contain any misspelled words?

A. The suspect remained detained while the police conducted their inquisition.
B. The suspect remained detained while the police conducted their inquisition.
C. The suspect remained detained while the police conducted their inquisition.
D. The suspect remained detained while the police conducted their inquisition.

Correct answer: D

Rationale: The correct version of the sentence is option D: 'The suspect remained detained while the police conducted their inquisition.' This option is correct as it does not contain any misspelled words. 'Inquisition' is spelled correctly in this option, while the other options have misspelled variations of the word. Option A, B, and C all contain misspelled versions of 'inquisition,' making them incorrect choices.

3. Which phenomenon describes the separation of light into its component colors when passing through a prism?

A. Refraction
B. Diffraction
C. Dispersion
D. Reflection

Correct answer: C

Rationale: Dispersion is the phenomenon that describes the separation of light into its component colors when passing through a prism. When white light enters a prism, it is refracted at different angles depending on its wavelength, causing the colors to spread out. Refraction is the bending of light as it passes from one medium to another, not the separation of colors. Diffraction is the bending of light around obstacles, not the separation of colors. Reflection is the bouncing back of light rays from a surface, not the separation of colors. In the context of a prism, dispersion plays a key role in the creation of a spectrum of colors by separating the different wavelengths present in white light.

4. What is the scientific name for the common housefly?

A. Musca domestica
B. Drosophila melanogaster
C. Apis mellifera
D. Anopheles gambiae

Correct answer: A

Rationale: Musca domestica is the scientific name for the common housefly. This species is known for being a common pest found in and around human habitations. Drosophila melanogaster (option B) is a species of fruit fly commonly used in genetic research. Apis mellifera (option C) is the scientific name for the western honeybee. Anopheles gambiae (option D) is a species of mosquito known for being a vector of malaria.

5. Which of the following is a constant?

A. The number of protons in an oxygen atom
B. The temperature at which iron ore will melt
C. The human population size
D. The time the sun rises each day

Correct answer: A

Rationale: The number of protons in an oxygen atom is a constant. This value is determined by the atomic number of the element and does not change regardless of the isotope of oxygen. The number of protons defines the element and remains consistent under normal conditions. Choices B, C, and D are not constants. The temperature at which iron ore will melt can vary depending on factors like pressure, the human population size is constantly changing, and the time the sun rises each day varies with the seasons and location.