Nursing Elites

1. What are the microscopic units responsible for muscle contraction called?

• A. Neurons
• B. Myofibrils
• C. Tendons
• D. Sarcomeres

Correct answer: D

Rationale: Sarcomeres are the fundamental contractile units of skeletal muscles and are responsible for muscle contraction. They consist of actin and myosin filaments that slide past each other during muscle contraction. Neurons are responsible for transmitting signals to and from muscles but are not directly involved in muscle contraction. Myofibrils are composed of sarcomeres and are the structures within muscle cells where muscle contractions take place. Tendons are connective tissues that attach muscles to bones and are not directly involved in muscle contraction.

2. What is the most basic unit of structure in living things?

• A. Cell
• B. Organelle
• C. Oxygen
• D. Pigment

Correct answer: A

Rationale: The cell is indeed the most basic unit of life, forming the foundation of all living organisms. Cells are the building blocks of all living things, containing organelles that perform specific functions. While oxygen is essential for life, it is not a structural unit. Similarly, pigment is a component found within cells but is not the fundamental unit of structure. Therefore, the correct answer is 'A: Cell.'

3. What is the name of the microscopic filtering unit within the kidney responsible for waste removal and blood volume regulation?

• A. Nephron
• B. Ureteric bud
• C. Renal pyramid
• D. Glomerulus

Correct answer: A

Rationale: The correct answer is A: Nephron. The nephron is the functional unit of the kidney responsible for waste removal and blood volume regulation. It is composed of several structures, including the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct. The other options mentioned in the question (ureteric bud, renal pyramid, and glomerulus) are not the correct names for the microscopic filtering unit within the kidney. The glomerulus is a part of the nephron, specifically responsible for ultrafiltration in the initial stage of urine formation.

4. Which of the following Mendelian laws describes how pairs of alleles within genes separate and recombine independently from other genes?

• A. law of segregation
• B. law of dominance
• C. law of independent assortment
• D. law of predictive traits

Correct answer: C

Rationale: The law of independent assortment describes how alleles of different genes segregate independently during gamete formation. This means that different gene pairs are passed on to offspring separately from one another, allowing for various combinations of traits. Gregor Mendel discovered this law, along with the law of segregation and the law of dominance, through his experiments with pea plants. The law of segregation (choice A) refers to how alleles of a gene separate during gamete formation, while the law of dominance (choice B) states that one allele can mask the presence of another in a heterozygous individual. The 'law of predictive traits' (choice D) is not a recognized Mendelian law and does not accurately describe the principles of genetic inheritance.

5. Which structure do cells rely on for movement?

• A. Flagellum
• B. Microtubule
• C. Pili
• D. Vesicle

Correct answer: A

Rationale: The correct answer is A: Flagellum. Cells rely on flagella for movement, which are whip-like structures that propel the cell forward through their whipping motion. Flagella provide motility to single-celled organisms and certain cells in multicellular organisms. Microtubules, on the other hand, provide structural support to the cell and play a role in intracellular transport. Pili are short, hair-like structures used for attachment to surfaces or other cells, not for movement. Vesicles are membrane-bound sacs involved in intracellular transport, aiding in the movement of substances within the cell, but not in the movement of the cell itself.

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