Nursing Elites

1. What are the key differences between cytokinesis in plant and animal cells?

• A. Animal cells utilize an actomyosin ring for cleavage furrow formation, while plant cells lack this mechanism.
• B. Plant cells rely on the assembly of a cell plate in the center of the dividing cell, ultimately separating the cytoplasm.
• C. Cytokinesis in both plant and animal cells is driven by the expansion of the endoplasmic reticulum.
• D. Both types of cells achieve cytokinesis through similar membrane pinching and constriction mechanisms.

Correct answer: B

Rationale: Rationale: A) Animal cells utilize an actomyosin ring for cleavage furrow formation, while plant cells lack this mechanism. - This statement is true. Animal cells use an actomyosin ring to form a cleavage furrow during cytokinesis, while plant cells do not have this mechanism. Instead, plant cells form a cell plate. B) Plant cells rely on the assembly of a cell plate in the center of the dividing cell, ultimately separating the cytoplasm. - This statement is correct. Plant cells form a cell plate in the middle of the dividing cell during cytokinesis. The cell plate eventually develops into a new cell wall that separates the two daughter cells. C) Cytokinesis in both plant and animal cells is driven by the expansion of the endoplasmic reticulum. - This

2. Which phenomenon explains the formation of rainbows in the sky?

• A. Diffraction
• B. Interference
• C. Refraction and dispersion of sunlight by water droplets.
• D. Reflection from clouds

Correct answer: C

Rationale: Refraction and dispersion of sunlight by water droplets in the atmosphere separate white light into its constituent colors, creating the rainbow phenomenon.

3. What is the structure that attaches to each chromosome during mitosis?

• A. Centromere
• B. Telomere
• C. Spindle apparatus
• D. Nucleolus

Correct answer: A

Rationale: Rationale: The centromere is the structure that attaches to each chromosome during mitosis. It is a region of the chromosome where the two sister chromatids are held together and where the spindle fibers attach during cell division. The centromere plays a crucial role in ensuring that each daughter cell receives the correct number of chromosomes during cell division. Telomeres are structures found at the ends of chromosomes that protect them from deterioration and fusion with neighboring chromosomes. The spindle apparatus is a structure made of microtubules that helps separate chromosomes during cell division. The nucleolus is a region within the nucleus where ribosomal RNA synthesis occurs and is not directly involved in chromosome attachment during mitosis.

4. Which of the following structures plays a crucial role in controlling the cell cycle and preventing uncontrolled cell growth?

• A. The centrioles
• B. The nucleolus
• C. The Golgi apparatus
• D. The endoplasmic reticulum

Correct answer: A

Rationale: Rationale: - Centrioles are cylindrical structures found in animal cells that play a crucial role in organizing the spindle fibers during cell division (mitosis). They are involved in the separation of chromosomes during cell division, ensuring that each daughter cell receives the correct number of chromosomes. - Centrioles are also involved in the formation of cilia and flagella, which are important for cell motility and sensory functions. - The other structures listed in the options (nucleolus, Golgi apparatus, and endoplasmic reticulum) do not directly play a role in controlling the cell cycle and preventing uncontrolled cell growth.

5. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: c

Rationale: The primary function of the myelin sheath that surrounds some axons in the nervous system is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer, which helps nerve impulses travel faster along the axon by allowing them to 'jump' from one node of Ranvier to the next, a process known as saltatory conduction. This increases the efficiency and speed of signal transmission, enabling rapid communication within the nervous system. Therefore, option C is the correct answer as it accurately describes the role of the myelin sheath in enhancing the speed of nerve impulse transmission.

6. A person is pushing a box across the floor. Which of the following forces is NOT doing work?

• A. The person's pushing force
• B. The normal force from the floor
• C. The gravitational force on the box
• D. The frictional force between the box and the floor

Correct answer: A

Rationale: Work is defined as the force applied in the direction of motion multiplied by the distance moved. Since the normal force acts perpendicular to the motion, it does not contribute to work.

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