Nursing Elites

1. Why are bacteria and blue-green algae often classified together?

• A. Both are gymnosperms.
• B. Both are prokaryotes.
• C. Both are autotrophs.
• D. Both are pathogens.

Correct answer: B

Rationale: Bacteria and blue-green algae (cyanobacteria) are often classified together because they are both prokaryotes. Prokaryotes are unicellular organisms that lack a membrane-bound nucleus and other membrane-bound organelles. This characteristic distinguishes them from eukaryotic organisms, which have these membrane-bound structures. Choice A is incorrect because gymnosperms are seed-producing plants with naked seeds, not bacteria or blue-green algae. Choice C is incorrect because being an autotroph (able to produce its own food) is not a reason for classifying them together. Choice D is incorrect because not all bacteria and blue-green algae are pathogens; many of them are beneficial or neutral to other organisms.

2. Which organelle provides storage space for the cell?

• A. Mitochondrion
• B. Vacuole
• C. Cell membrane
• D. Ribosome

Correct answer: B

Rationale: The correct answer is B: Vacuole. The vacuole is the organelle responsible for providing storage space in the cell. It stores water, nutrients, waste products, and other essential materials required by the cell. Vacuoles are crucial for maintaining cell structure and regulating cellular processes. Mitochondrion (choice A) is known as the powerhouse of the cell, responsible for producing energy. The cell membrane (choice C) is a protective barrier around the cell, regulating what enters and exits the cell. Ribosomes (choice D) are involved in protein synthesis, not storage.

3. How are molecules of water bonded to each other?

• A. Ionic
• B. Covalent
• C. Hydrogen
• D. Molecular

Correct answer: C

Rationale: Water molecules are bonded to each other by 'hydrogen' bonds. These bonds are not as strong as covalent bonds, which hold the atoms within each water molecule together (Choice B). Ionic bonds (Choice A) involve the transfer of electrons between atoms, which is not the case in water molecules. The term 'molecular' (Choice D) is too general and doesn't specifically describe the type of bond between water molecules.

4. What is the initial step in the metabolism of food to cellular energy?

• A. Citric Acid Cycle
• B. Glycolysis
• C. Electron Transport Chain
• D. Photosynthesis

Correct answer: B

Rationale: The correct answer is B: Glycolysis. Glycolysis is the initial step in the metabolism of food to cellular energy. During glycolysis, glucose is broken down into pyruvate, generating ATP and NADH. Choices A, C, and D are incorrect because the Citric Acid Cycle and Electron Transport Chain occur later in cellular respiration, while Photosynthesis is the process by which plants convert light energy into chemical energy.

5. What is the role of tRNA during protein synthesis?

• A. Carries amino acids to the ribosome
• B. Links nucleotides together
• C. Copies DNA sequences
• D. Replicates genetic material

Correct answer: A

Rationale: During protein synthesis, tRNA plays the crucial role of carrying amino acids to the ribosome. This process ensures that the correct amino acids are brought to the ribosome according to the mRNA sequence. Choice B, linking nucleotides together, refers to the role of RNA polymerase in transcription, not tRNA. Choice C, copying DNA sequences, is the function of DNA polymerase during DNA replication, while choice D, replicating genetic material, is an overarching function of DNA replication, not specific to tRNA's role in protein synthesis.

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