Nursing Elites

1. In what way does 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: Rationale: A) Misaligned chromosomes fail to attach to microtubules, triggering a delay in anaphase onset: During cell division, proper attachment of chromosomes to spindle fibers is crucial for accurate segregation of genetic material. If chromosomes are not correctly attached to microtubules, it can lead to misalignment, which triggers a delay in anaphase onset. This delay allows the cell to correct any errors before proceeding with cell division. B) The presence of unattached kinetochores on the centromeres sends a signal to pause cell cycle progression: Kinetochores are protein structures located at the centromere of chromosomes and are responsible for attaching chromosomes to spindle fibers. When kinetochores are unattached or improperly attached to microtubules, it sends a signal to the cell to pause cell cycle progression. This pause allows the cell to ensure that all chromosomes are properly aligned before proceeding with cell division.

2. An Egyptian model pyramid has a square base side length of 10cm and a height of 8cm. What is its volume?

• A. 20 cu cm
• B. 40 cu cm
• C. 80 cu cm
• D. 160 cu cm

Correct answer: D

Rationale: Use the formula for volume of a pyramid: (1/3) * base area * height. Calculate the base area (10cm * 10cm = 100 sq cm) and substitute: (1/3) * 100 sq cm * 8cm = 80 cu cm.

3. Which property of a substance refers to its ability to be hammered or pressed into thin sheets without breaking?

• A. Malleability
• B. Ductility
• C. Viscosity
• D. Conductivity

Correct answer: a

Rationale: Malleability is the property that describes a substance's ability to be hammered or pressed into thin sheets without breaking.

4. Which of the following is a strong acid?

• A. Acetic acid (CH₃COOH)
• B. Hydrochloric acid (HCl)
• C. Citric acid
• D. Carbonic acid (Hâ‚‚CO₃)

Correct answer: b

Rationale: Hydrochloric acid is a strong acid, meaning it completely ionizes in water to produce hydrogen ions. The other choices are weak acids.

5. Polymers are

• A. Large molecules formed by repeating units called monomers
• B. Simple organic molecules with low boiling points
• C. Highly reactive compounds used in industrial processes
• D. Insoluble solids with no definite structure

Correct answer: A

Rationale: The correct answer is A: 'Large molecules formed by repeating units called monomers.' Polymers are macromolecules made up of repeating units called monomers, which are linked together through chemical bonds. This repetition results in long chains or networks of molecules, giving polymers their unique properties. Options B, C, and D are incorrect because polymers are not simple organic molecules with low boiling points, highly reactive compounds used in industrial processes, or insoluble solids with no definite structure. Understanding the basic definition of polymers helps us appreciate their wide range of applications in materials science, engineering, and everyday products.

6. A car is traveling on a curved road. What force keeps the car moving along the curved path?

• A. Gravitational force
• B. Normal force from the road
• C. Air resistance
• D. Friction between the tires and the road

Correct answer: D

Rationale: In this case, static friction acts between the tires and the road, providing the centripetal force required to keep the car moving in a circle even though it's traveling in a straight line relative to the ground.

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