Nokea
Which of the following is not a product of the Krebs cycle?
- A. carbon dioxide
- B. oxygen
- C. adenosine triphosphate (ATP)
- D. energy carriers
Correct Answer: B
Rationale: The correct answer is B, 'oxygen.' The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that produce energy-rich molecules like ATP, carbon dioxide, and energy carriers such as NADH and FADH2. Oxygen is not a direct product of the Krebs cycle but is essential for the electron transport chain, which follows the Krebs cycle and is where oxygen is used as the final electron acceptor.
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Which set is correctly listed from largest to smallest group?
- A. Genus, order, species, phylum.
- B. Phylum, order, genus, species.
- C. Order, phylum, species, genus.
- D. Species, order, phylum, genus.
Correct Answer: B
Rationale:
What must any solution injected into tissues be to prevent cells from shrinking or swelling?
- A. Distilled.
- B. Hypertonic.
- C. Hypotonic.
- D. Isotonic.
Correct Answer: D
Rationale: The correct answer is D: Isotonic. An isotonic solution has the same concentration of solutes as the cells in the tissues, preventing them from shrinking or swelling. If a solution is hypertonic (choice B), it has a higher solute concentration and would cause cells to shrink due to water leaving the cells. A hypotonic solution (choice C) has a lower solute concentration and would cause cells to swell as water enters the cells. Distilled water (choice A) lacks solutes and would cause cells to swell. Overall, an isotonic solution maintains cell volume and prevents any osmotic imbalances.
Select the cell parts that are present in plant cells but not animal cells (there may be more than one answer):
- A. Cell membrane
- B. Cell wall
- C. Ribosome
- D. Chloroplast
Correct Answer: D
Rationale: Chloroplasts are unique to plant cells and are responsible for photosynthesis, a process that converts light energy into chemical energy. Animal cells do not contain chloroplasts as they do not perform photosynthesis. Therefore, the correct answer is D - Chloroplast. The cell membrane is found in both plant and animal cells, serving as a protective barrier, while the cell wall is a rigid structure present in plant cells that provides support and protection. Ribosomes are cellular structures responsible for protein synthesis and are present in both plant and animal cells.
Which vitamin is recognized for its healing antioxidant properties?
- A. Vitamin D
- B. Vitamin K
- C. Vitamin A
- D. Vitamin E
Correct Answer: C
Rationale: Vitamin A is well-known for its antioxidant properties, essential for healing, maintaining healthy skin and tissues, and supporting the immune system. It plays a vital role in repairing damaged tissues, making it crucial for overall health and facilitating healing processes.
Why does cytokinesis occur?
- A. To duplicate DNA
- B. To convert energy within organelles
- C. To eliminate bacteria
- D. To divide daughter cells
Correct Answer: D
Rationale: Cytokinesis is the process of cell division following mitosis, where the cytoplasm of a cell is split into two daughter cells. The main purpose of cytokinesis is to physically separate the newly formed nuclei and organelles into individual cells, ensuring that each daughter cell receives a complete set of cellular components to function independently. Therefore, the correct answer is D, as the primary outcome of cytokinesis is the division of daughter cells.