Nursing Elites

1. What does half-life refer to?

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: Half-life refers to the time it takes for half of the radioactive atoms in a sample to decay. This means that after one half-life, half of the initial quantity of the radioactive substance will have decayed. Choice A is incorrect because radioactive intensity doesn't completely disappear during half-life. Choice B is incorrect as half-life doesn't refer to the number of neutrons doubling. Choice C is incorrect as half-life doesn't relate to the number of protons changing.

2. Which of these is NOT a function of the large intestine?

• A. Absorbing water and electrolytes
• B. Producing vitamins
• C. Breaking down fiber
• D. Eliminating waste products

Correct answer: B

Rationale: A) Absorbing water and electrolytes: The large intestine plays a crucial role in absorbing water and electrolytes from the indigestible food matter that passes through it. This helps in maintaining the body's fluid balance and preventing dehydration. B) Producing vitamins: While the large intestine contains bacteria that can produce some vitamins like vitamin K and certain B vitamins, the primary site for vitamin production is the small intestine and other organs like the liver. Therefore, producing vitamins is not a primary function of the large intestine. C) Breaking down fiber: The large intestine is responsible for breaking down fiber that was not digested in the small intestine. The bacteria in the large intestine ferment fiber, producing short-chain fatty acids that can be used as an energy source by the body. D) Eliminating waste products: One of the main functions of the large intestine is to eliminate waste products, including indigestible food matter, dead cells, and bacteria, from the body in the form of feces. Therefore, the correct answer is B, as producing vitamins is not a primary function of the large intestine.

3. In a study where fish are fed different amounts of food daily for four weeks in separate tanks, with fish weight measured weekly, what is the dependent variable?

• A. Weight of the fish
• B. Type of food used
• C. Number of fish tanks
• D. Frequency of feedings

Correct answer: A

Rationale: The weight of the fish is the dependent variable in this study because it is the outcome being measured in response to the varying feeding amounts. The weight of the fish changes based on the feeding regimen, making it the dependent variable. The type of food used (choice B), number of fish tanks (choice C), and frequency of feedings (choice D) are not the dependent variables in this study. These factors may be independent variables that are manipulated or controlled in the experiment to observe their impact on the dependent variable, which is the weight of the fish.

4. Testosterone is a crucial hormone in the male reproductive system. What is its primary function?

• A. Egg production
• B. Sperm production and development
• C. Regulation of the menstrual cycle
• D. Milk production

Correct answer: B

Rationale: Testosterone is a hormone primarily produced in the testes of males and is responsible for the development of male reproductive tissues, including the testes and prostate. Its primary function is the production and maturation of sperm cells, as well as the development of secondary sexual characteristics in males. Choice A, 'Egg production,' is incorrect as testosterone is not involved in the production of eggs. Choice C, 'Regulation of the menstrual cycle,' is incorrect because testosterone is not responsible for regulating the menstrual cycle, which is primarily governed by female hormones. Choice D, 'Milk production,' is incorrect as testosterone does not play a role in milk production, which is associated with other hormones like prolactin in females.

5. What is the SI unit of measurement for momentum?

• A. Newton (N)
• B. Kilogram-meter per second (kg·m/s)
• C. Joule (J)
• D. Newton-second (N·s)

Correct answer: B

Rationale: The correct SI unit of measurement for momentum is kilogram-meter per second (kg·m/s). Momentum is a vector quantity that is calculated by multiplying an object's mass (in kilograms) by its velocity (in meters per second), resulting in the unit kg·m/s. This unit represents the quantity of motion an object possesses, taking into account both the mass and velocity of the object. Choice A, Newton (N), is the unit of force, not momentum. Choice C, Joule (J), is the unit of energy, not momentum. Choice D, Newton-second (N·s), is the unit of impulse, not momentum.

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