Nursing Elites

1. In nuclear physics, the term 'barn' is a unit commonly used to quantify:

• A. Energy
• B. Radioactivity
• C. Nuclear cross-section
• D. Half-life

Correct answer: C

Rationale: In nuclear physics, the term 'barn' is a unit used to quantify nuclear cross-section. Nuclear cross-section is a measure of the probability of a nuclear reaction occurring when an atomic nucleus interacts with a particle or another nucleus. The barn is a unit of area equal to 10^-28 square meters; it is commonly used to describe the cross-sectional area of atomic nuclei for nuclear reactions. Choice A, 'Energy,' is incorrect because a barn is not a unit for measuring energy; it is a unit of area. Choice B, 'Radioactivity,' is incorrect as radioactivity is typically measured in units like becquerels. Choice D, 'Half-life,' is also incorrect as half-life is a measure of the time it takes for half of a substance to decay, not related to the concept of a barn as a unit of nuclear cross-section.

2. With which genotype would the recessive phenotype appear if the dominant allele is marked with 'A' and the recessive allele is marked with 'a'?

• A. AA
• B. aa
• C. Aa
• D. aA

Correct answer: B

Rationale: The recessive phenotype appears when an individual has two copies of the recessive allele. In this case, the recessive allele is marked with 'a.' Therefore, the genotype 'aa' would display the recessive phenotype as both alleles are recessive. Choice A (AA) has two dominant alleles, choice C (Aa) has one dominant and one recessive allele, and choice D (aA) represents the same genotype as Aa due to the principle of allele dominance.

3. Which of the following is the smallest unit of matter?

• A. Molecule
• B. Atom
• C. Compound
• D. Element

Correct answer: B

Rationale: An atom is the fundamental building block of matter, while molecules are formed by the combination of atoms.

4. What are chromosomes made of?

• A. DNA and RNA
• B. DNA and protein
• C. Protein and RNA
• D. DNA and lipids

Correct answer: B

Rationale: Chromosomes are made up of DNA and associated proteins. These proteins help package and organize the DNA within the cell, playing a crucial role in gene regulation and cell division. While RNA is involved in various cellular processes, it is not a primary component of chromosomes. Lipids are not a fundamental component of chromosomes, which primarily consist of DNA and proteins.

5. Which organ's primary role is the production of bile and other metabolic functions such as blood sugar regulation and detoxification?

• A. Gallbladder
• B. Pancreas
• C. Liver
• D. Stomach

Correct answer: C

Rationale: The correct answer is the liver. The liver is responsible for producing bile, regulating blood sugar levels, and detoxifying the blood. Bile produced by the liver is stored in the gallbladder. The pancreas primarily functions in digestion by producing enzymes and insulin, while the stomach is mainly involved in breaking down food through the secretion of gastric juices.

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