which muscle is voluntary striated and found in bones

ATI TEAS 7

ATI TEAS Science Questions

1. Which muscle is voluntary, striated, and found attached to bones?

A. Smooth muscle
B. Skeletal muscle
C. Cardiac muscle
D. Epithelial muscle

Correct answer: B

Rationale: The correct answer is B, Skeletal muscle. Skeletal muscle is both voluntary and striated, as well as attached to bones, allowing for movement. Smooth muscle, on the other hand, is involuntary and typically found in the walls of internal organs, controlling functions like digestion. Cardiac muscle is also striated, but it is involuntary and specifically found in the heart, responsible for cardiac contractions to pump blood. 'Epithelial muscle' is an incorrect term; epithelial tissue is a type of tissue that forms the linings of various body surfaces and structures, not a muscle type.

2. How do spindle fiber dynamics and microtubule attachment regulate cell cycle checkpoints?

A. Misaligned chromosomes fail to attach to microtubules, triggering a delay in anaphase onset.
B. The presence of unattached kinetochores on the centromeres sends a signal to pause cell cycle progression.
C. Microtubule instability and rapid depolymerization lead to the activation of checkpoint proteins.
D. All of the above.

Correct answer: D

Rationale: A) Misaligned chromosomes fail to attach to microtubules, triggering a delay in anaphase onset: Proper attachment of chromosomes to spindle fibers is essential for accurate segregation of genetic material during cell division. Misaligned chromosomes that fail to attach to microtubules can lead to delays in anaphase onset, allowing the cell to correct errors before proceeding with division. B) The presence of unattached kinetochores on the centromeres sends a signal to pause cell cycle progression: Kinetochores at the centromeres help attach chromosomes to spindle fibers. When kinetochores are unattached or improperly attached to microtubules, they signal the cell to pause cell cycle progression, ensuring proper chromosome alignment before division. C) Microtubule instability and rapid depolymerization lead to the activation of checkpoint proteins: While microtubule dynamics are crucial for cell division, microtubule instability and rapid depolymerization can disrupt chromosome attachment. However, this mechanism is not directly related to the activation of cell cycle checkpoint proteins, making this statement incorrect. Therefore, choices A and B accurately describe how spindle fiber dynamics and microtubule attachment regulate cell cycle checkpoints, making option D the correct answer.

3. 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.

4. How does electron configuration relate to the periodic table?

A. Elements within the same period have identical electron configurations.
B. Elements within the same group share similar electron configurations in their outermost shell.
C. Electron configuration determines an element's position on the periodic table.
D. An element's group on the periodic table is determined by the number of electron shells it possesses.

Correct answer: B

Rationale: Elements within the same group share similar electron configurations in their outermost shell. The periodic table is organized based on the number of electrons in the outermost energy level, known as valence electrons, which significantly influence an element's chemical properties. Elements within the same group have the same number of valence electrons, leading to comparable chemical behaviors. Choices A and D are incorrect because elements within the same period, not group, have identical electron configurations, and an element's group is primarily determined by the number of valence electrons and not the number of electron shells. Choice C is incorrect because while electron configuration is crucial for understanding an element's properties, it is not the sole factor determining its position on the periodic table.