Nursing Elites

1. Blood type is a trait determined by multiple alleles, with IA and IB being co-dominant: IA codes for A blood and IB codes for B blood, while i codes for O blood and is recessive to both. If an A heterozygote individual and an O individual have a child, what is the probability that the child will have A blood?

• A. 25%
• B. 50%
• C. 75%
• D. 100%

Correct answer: B

Rationale: If an A heterozygote (IAi) and an O individual (ii) have a child, there is a 50% chance the child will inherit the IA allele and have A blood. The A heterozygote can pass on either the IA or i allele, while the O individual can only pass on the i allele. Therefore, the possible genotypes for the child are IAi (A blood) or ii (O blood), resulting in a 50% chance of the child having A blood. Choice A (25%) is incorrect as it does not take into account the possibility of inheriting the IA allele. Choice C (75%) and Choice D (100%) are incorrect as they overestimate the probability of the child having A blood.

2. What is an isotope? For any given element, it is an atom with which of the following?

• A. a different atomic number
• B. a different number of protons
• C. a different number of electrons
• D. a different mass number

Correct answer: D

Rationale: An isotope of an element is an atom with a different number of neutrons, resulting in a different mass number. Isotopes of the same element have the same number of protons (which determines the element's identity) but differ in the number of neutrons, leading to variations in mass numbers. Choice A is incorrect because isotopes of the same element have the same atomic number. Choice B is incorrect because isotopes of the same element have the same number of protons. Choice C is incorrect because isotopes of the same element have the same number of electrons.

3. Which of the following statements regarding the working of the heart is not correct?

• A. The atria contract, and the valves open to allow blood into the ventricles.
• B. The heartbeat begins when the heart muscles relax, and blood flows into the atria.
• C. The valves close to stop blood from flowing backward.
• D. The ventricles contract, forcing blood to leave the heart.

Correct answer: B

Rationale: The correct answer is B because the heartbeat actually begins when the heart muscles relax, allowing the chambers to fill with blood. The contraction phase follows, which propels blood out of the heart. The other statements are accurate in describing the normal sequence of events in the heart's functioning: the atria contract to push blood into the ventricles, the valves close to prevent backflow of blood, and the ventricles contract to pump blood out of the heart.

4. What is the term for the time it takes for a wave to complete one full cycle?

• A. Frequency
• B. Amplitude
• C. Period
• D. Wavelength

Correct answer: C

Rationale: The period of a wave is the time it takes for one complete cycle to occur. It is the duration between two successive points in the wave that are in the same phase. Frequency, on the other hand, refers to the number of cycles of a wave that occur in a given time period. Amplitude represents the maximum displacement of a wave from its equilibrium position. Wavelength is the distance between two consecutive points on a wave that are in phase. Therefore, the correct answer is 'Period' as it specifically refers to the time taken for a wave to complete one full cycle, distinguishing it from the other choices which represent different properties of a wave.

5. What is the shape of the DNA molecule?

• A. Linear
• B. Circular
• C. Double helix
• D. Straight chain

Correct answer: C

Rationale: The correct answer is C: Double helix. The shape of the DNA molecule is a double helix, a structure first described by James Watson and Francis Crick in 1953. This shape consists of two strands twisted around each other in a spiral. The double helix structure allows DNA to be compactly stored within the cell nucleus and provides stability to the molecule. Options (A) Linear, (B) Circular, and (D) Straight chain are incorrect as they do not accurately represent the shape of the DNA molecule. DNA is not linear but rather forms a twisted double helix; it is not circular like a ring but has a spiral structure, and it is not a straight chain but a twisted ladder-like structure.

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