Nursing Elites

1. Which of these body parts does not contain melanin?

• A. Hair
• B. Nails
• C. Skin
• D. Iris

Correct answer: D

Rationale: The iris is the colored part of the eye that determines the eye's color. Melanin is not present in the iris, unlike hair, nails, and skin. Melanin gives color to hair, nails, and skin, but not to the iris. Therefore, the correct answer is the iris (Choice D). Choices A, B, and C contain melanin and are incorrect.

2. What defines the systole phase in the cardiac cycle?

• A. Relaxation of the heart
• B. Contraction of the heart
• C. Diastole of the heart
• D. Pulse rate of the heart

Correct answer: B

Rationale: The correct answer is B: Contraction of the heart. Systole is the phase of the cardiac cycle during which the heart muscle contracts, pumping blood out of the chambers. It is essential for maintaining circulation and delivering oxygen and nutrients to the body's tissues. Diastole (choice C) is the relaxation phase of the heart when the chambers fill with blood. Pulse rate (choice D) is the number of heartbeats per minute, not specifically related to the systole phase. Choice A, 'Relaxation of the heart,' is incorrect because systole refers to the contraction phase of the cardiac cycle, not relaxation.

3. What is the primary function of platelets in the blood?

• A. To carry oxygen
• B. To clot blood
• C. To fight infection
• D. To transport nutrients

Correct answer: B

Rationale: The correct answer is B: 'To clot blood.' Platelets play a crucial role in the clotting process, forming a plug at the site of blood vessel injury to prevent excessive bleeding. While red blood cells carry oxygen, white blood cells fight infection, and nutrients are transported by plasma, platelets are specifically responsible for blood clotting. Choice A is incorrect because red blood cells are responsible for carrying oxygen. Choice C is incorrect because white blood cells are primarily involved in fighting infection. Choice D is incorrect as the transport of nutrients is mainly carried out by plasma, not platelets.

4. How are genetic markers utilized in paternity testing?

• A. They identify unique sequences in the father's DNA present in the child.
• B. They analyze the presence or absence of specific alleles for certain genes.
• C. They compare the child's blood type to the parents' blood types.
• D. They measure the child's physical resemblance to the father.

Correct answer: B

Rationale: Genetic markers are specific DNA sequences that can vary among individuals. In paternity testing, genetic markers are used to compare the DNA of the child with that of the alleged father. By analyzing the presence or absence of specific alleles (different forms of a gene) at these genetic markers, scientists can determine the likelihood of paternity. This method is more accurate and reliable than comparing blood types (choice C) or physical resemblance (choice D) as genetic markers provide a direct comparison of DNA sequences between individuals. Therefore, option B is the correct choice as it accurately describes the use of genetic markers in paternity testing.

5. What type of particle carries no charge and mediates the strong nuclear force between protons and neutrons?

• A. Electron
• B. Photon
• C. Gluon
• D. Neutrino

Correct answer: C

Rationale: The correct answer is C: Gluon. Gluons are the particles responsible for mediating the strong nuclear force between protons and neutrons. They are the carriers of this force. Choice A, Electron, is incorrect as electrons are negatively charged. Choice B, Photon, is incorrect as photons are chargeless particles of light. Choice D, Neutrino, is incorrect as neutrinos are neutral particles with minimal mass and weak interactions with matter, not involved in mediating the strong nuclear force between protons and neutrons.

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