Nursing Elites

1. What provides the cell with the ability to move and propel?

• A. Microfilaments
• B. Microtubules
• C. Flagella
• D. Cilia

Correct answer: B

Rationale: Microtubules are the cellular structures responsible for cell movement and propulsion. Microtubules are part of the cytoskeleton and play a crucial role in various cellular processes, including cell motility and intracellular transport. While microfilaments also contribute to cell movement by enabling muscle contraction and cell shape changes, they are not primarily responsible for propelling the cell. Flagella and cilia are cellular appendages involved in cell movement, but they are composed of microtubules, making them the structures that move due to the actions of microtubules.

2. Which of the following is not true about enzymes?

• A. They catalyze reactions
• B. They lower the activation energy needed
• C. They have an active site
• D. They are typically proteins

Correct answer: B

Rationale: Enzymes lower the activation energy needed for a reaction to occur, not raise it. By lowering the activation energy, enzymes facilitate reactions, making them occur more easily and rapidly. Choice A is correct as enzymes indeed catalyze reactions. Choice C is correct as enzymes have specific active sites where substrates bind. Choice D is correct as enzymes are commonly proteins, although some RNA molecules also exhibit catalytic properties.

3. The difference between diploid and haploid is as follows:

• A. Diploid organisms are multicellular
• B. Diploid cells are somatic
• C. Diploid cells have two sets of homologous chromosomes
• D. More than one of the above is true

Correct answer: D

Rationale: Option B correctly states that diploid cells are somatic cells that make up the body tissues and organs in an organism, while haploid cells are gametes involved in sexual reproduction. Option C accurately differentiates diploid and haploid cells based on their chromosome sets – diploid cells have two sets of homologous chromosomes (one from each parent), whereas haploid cells have one set of unpaired chromosomes. Therefore, the correct choice is D, as both statements in options B and C are accurate descriptions of the differences between diploid and haploid cells. Option A is incorrect because diploid and haploid refer to the number of sets of chromosomes in a cell, not whether the organism is multicellular or not.

4. What is necessary for active transport through a membrane to take place?

• A. Glucose
• B. Oxygen
• C. Sodium
• D. ATP

Correct answer: D

Rationale: Active transport through a membrane requires energy in the form of ATP (adenosine triphosphate). ATP provides the necessary energy for the transport proteins to move molecules against the concentration gradient, from an area of lower concentration to higher concentration. This process is essential for maintaining cellular functions and regulating the internal environment of a cell. Glucose, oxygen, and sodium are important molecules involved in various cellular processes, but they are not the primary energy source required for active transport across membranes. Therefore, the correct answer is ATP.

5. What kind of bond connects sugar and phosphate in DNA?

• A. hydrogen
• B. ionic
• C. covalent
• D. overt

Correct answer: C

Rationale: Sugar and phosphate are indeed connected by covalent bonds in DNA. Covalent bonds involve the sharing of electrons between atoms, which is essential for forming the backbone of the DNA molecule. Hydrogen bonds (Choice A) are important in holding the nitrogenous bases together in the DNA double helix but do not connect sugar and phosphate. Ionic bonds (Choice B) involve the transfer of electrons between atoms and are not the primary bond connecting sugar and phosphate in DNA. 'Overt' (Choice D) is not a type of chemical bond and is an incorrect distractor.

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