Nursing Elites

1. What is the small repeating unit in the contractile apparatus of skeletal muscle?

• A. Myofibril
• B. Actin
• C. Sarcomere
• D. Myosin

Correct answer: C

Rationale: The correct answer is 'Sarcomere.' The sarcomere is the smallest repeating unit within myofibrils and is responsible for muscle contraction in skeletal muscle. It consists of overlapping actin and myosin filaments arranged in a highly organized structure that allows for the sliding of filaments during muscle contraction. 'Myofibril' (choice A) is incorrect because it is a larger structure composed of sarcomeres. 'Actin' (choice B) and 'Myosin' (choice D) are incorrect as they are individual proteins that are components of the sarcomere, not the smallest repeating unit itself.

2. What is a monohybrid cross, and what is the ratio of dominant to recessive gene manifestation?

• A. A cross involving two traits, 9:3:3:1
• B. A cross involving one trait, 3:1
• C. A cross involving two traits, 1:2:1
• D. A cross involving one trait, 1:1

Correct answer: B

Rationale: A monohybrid cross is a genetic cross involving one trait. The ratio of dominant to recessive gene manifestation in the offspring is typically 3:1 when both parents are heterozygous. This ratio is the genotypic ratio, not just the phenotype ratio, where the dominant allele is present in 3 out of 4 offspring, and the recessive allele is present in 1 out of 4 offspring. Choice A is incorrect because it describes a dihybrid cross ratio. Choice C is incorrect as it represents the genotypic ratio for a monohybrid cross involving incomplete dominance. Choice D is incorrect as it does not reflect the typical ratio for a monohybrid cross.

3. The term 'symbiotic relationship' describes an interaction between two organisms where:

• A. One organism benefits and the other is unaffected
• B. Both organisms are harmed by the interaction
• C. One organism benefits and the other is negatively impacted
• D. Both organisms benefit from the interaction

Correct answer: D

Rationale: In a symbiotic relationship, both organisms involved benefit from the interaction. This mutually beneficial relationship can take different forms, such as mutualism where both organisms benefit, commensalism where one organism benefits and the other is unaffected, or parasitism where one organism benefits at the expense of the other. In this case, the term 'symbiotic relationship' specifically refers to a scenario where both organisms derive some form of benefit from their interaction. Choices A, B, and C are incorrect because they do not accurately describe a symbiotic relationship. In symbiosis, both organisms benefit, making option D the correct choice.

4. What happens to the wavelength of a wave when its frequency increases while the speed remains constant?

• A. Wavelength increases
• B. Wavelength decreases
• C. Wavelength remains the same
• D. Wavelength becomes zero

Correct answer: B

Rationale: When the speed of a wave is constant and the frequency increases, the wavelength must decrease to keep the speed constant. The speed of a wave is determined by the product of frequency and wavelength (speed = frequency x wavelength). If the frequency increases while the speed remains constant, the wavelength has to decrease proportionally to maintain the speed unchanged. Therefore, as the frequency increases, the wavelength decreases to ensure that the speed of the wave remains constant. Choice A is incorrect because as frequency increases, wavelength decreases. Choice C is incorrect as the wavelength cannot remain the same when frequency increases while speed is constant. Choice D is incorrect as the wavelength cannot become zero under these conditions.

5. Which organ in the body is responsible for filtering toxins from the blood?

• A. Kidneys
• B. Liver
• C. Heart
• D. Lungs

Correct answer: B

Rationale: The liver is the organ responsible for filtering toxins from the blood. It plays a crucial role in detoxification by processing and eliminating harmful substances from the body. The kidneys primarily filter waste and excess substances from the blood to form urine, while the heart pumps blood throughout the body and the lungs facilitate gas exchange by oxygenating blood. Therefore, the correct answer is the liver as it is specifically involved in detoxifying the blood.

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