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. A lampshade consists of a cylindrical base (diameter 20cm, height 10cm) and a hemispherical top (same diameter as the base). What is its total surface area?

• A. 785 sq cm
• B. 1130 sq cm
• C. 1570 sq cm
• D. 2055 sq cm

Correct answer: D

Rationale: Calculate the surface area of the cylinder (base + lateral surface) and the hemisphere (half of a sphere's surface area). Add both areas to find the total surface area.

3. Which element is present in household bleach and has disinfectant properties?

• A. Sodium
• B. Chlorine
• C. Fluorine
• D. Iodine

Correct answer: B

Rationale: Chlorine's oxidizing ability makes it effective in killing bacteria and other microorganisms.

4. The epiglottis is a small flap of cartilage located near the base of the tongue. What is its role during swallowing?

• A. Initiates the swallowing reflex
• B. Grinds food into smaller pieces
• C. Covers the trachea to prevent food aspiration
• D. Stores saliva for lubrication

Correct answer: C

Rationale: The epiglottis is a crucial anatomical structure that covers the trachea during swallowing to prevent food aspiration. When we swallow, the epiglottis folds over the trachea, directing food and liquids down the esophagus instead of entering the airway. This action helps to ensure that the food and liquids go to the stomach for digestion and not into the lungs, which can lead to aspiration pneumonia, a serious condition. Therefore, option C, 'Covers the trachea to prevent food aspiration,' is the correct role of the epiglottis during swallowing.

5. In an SN2 reaction, the rate of the reaction is affected by

• A. Only the concentration of the nucleophile
• B. Only the concentration of the electrophile
• C. Neither the concentration of the nucleophile nor the electrophile
• D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. This is because in an SN2 reaction, the nucleophile directly attacks the electrophilic center, leading to the formation of the product. A higher concentration of nucleophile increases the chances of successful collisions with the electrophile, thereby increasing the reaction rate. Similarly, a higher concentration of the electrophile provides more reaction sites for the nucleophile to attack, also increasing the rate of the reaction. Therefore, both the nucleophile and electrophile concentrations play crucial roles in determining the rate of an SN2 reaction.

6. A person who carries a pathogen but does not exhibit any symptoms is considered:

• A. Asymptomatic carrier
• B. Opportunistic pathogen
• C. Nosocomial infection
• D. Vector-borne disease

Correct answer: A

Rationale: Rationale: An asymptomatic carrier is a person who carries a pathogen (such as a virus or bacterium) but does not show any symptoms of the infection themselves. Despite not exhibiting symptoms, asymptomatic carriers can still spread the pathogen to others, potentially causing illness in those who come into contact with them. This term specifically refers to individuals who are infected but do not develop symptoms, distinguishing them from symptomatic carriers who do show signs of the infection. Option A is the most appropriate choice in this context as it accurately describes a person who carries a pathogen without displaying symptoms. B) Opportunistic pathogen: This term refers to pathogens that typically do not cause disease in healthy individuals but can become pathogenic in individuals with weakened immune systems. C) Nosocomial infection: This term refers to infections that are acquired in a hospital or healthcare facility. D) Vector-borne disease: This term refers to diseases

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