Nokea
What is the function of water in photosynthesis?
- A. Combines with carbon dioxide
- B. Absorbs light energy
- C. Supplies electrons in the light reactions
- D. Transports hydrogen ions in the dark reactions
Correct Answer: C
Rationale: In photosynthesis, water plays a crucial role in supplying electrons during the light reactions of the process. When light energy is absorbed by chlorophyll, water molecules are split through photolysis, releasing electrons. These electrons are then used in the photosynthetic electron transport chain to generate ATP and NADPH, essential for the synthesis of sugars during the light-dependent reactions.
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Tonicity refers to the movement of:
- A. Water
- B. Solute
- C. Cells
- D. None of the above
Correct Answer: A
Rationale: Tonicity is a term used to describe the relative concentration of solutes inside and outside of a cell. When a solution is hypertonic, it has a higher concentration of solutes outside the cell, causing water to move out of the cell. When a solution is hypotonic, it has a lower concentration of solutes outside the cell, causing water to move into the cell. Therefore, tonicity primarily affects the movement of water across a cell membrane.
Which characteristic is typically found in prokaryotic cells?
- A. Have a nucleus
- B. Have a capsule
- C. Have membrane-bound organelles
- D. Cannot move on their own
Correct Answer: B
Rationale: Prokaryotic cells are characterized by the absence of a nucleus and membrane-bound organelles. One common feature of prokaryotic cells is the presence of a capsule, which is a protective layer outside the cell wall. This capsule helps protect the cell and can also assist in adherence to surfaces. Therefore, the correct characteristic typically found in prokaryotic cells is that they have a capsule.
What term describes the process of producing the RNA strand from a DNA template?
- A. Metabolism.
- B. Transcription.
- C. Synthesis.
- D. Replication.
Correct Answer: B
Rationale: The correct answer is B: Transcription. Transcription is the process where RNA is synthesized from a DNA template by RNA polymerase. During transcription, the DNA double helix unwinds, and one strand is used as a template to create a complementary RNA molecule. This process occurs in the cell nucleus and is essential for gene expression.
Choice A, Metabolism, refers to the chemical reactions that occur in living organisms to maintain life and is not directly related to RNA synthesis. Choice C, Synthesis, is a general term that does not specifically describe the process of RNA production from a DNA template. Choice D, Replication, is the process of copying DNA to create an identical DNA molecule, not RNA synthesis. Therefore, the correct term for producing an RNA strand from a DNA template is Transcription.
Which cell component is responsible for protection, communication, and regulating the passage of substances into and out of the cell?
- A. Nucleus
- B. Cell membrane
- C. Endoplasmic reticulum
- D. Cytoplasm
Correct Answer: B
Rationale: The cell membrane is responsible for protecting the cell, facilitating communication with other cells, and regulating the passage of substances into and out of the cell. It acts as a barrier that controls the movement of molecules, ions, and other substances, maintaining the cell's internal environment and enabling cellular interactions with the external environment. The nucleus contains genetic material and is not primarily involved in protection, communication, or regulating the passage of substances. The endoplasmic reticulum is involved in protein synthesis and lipid metabolism. The cytoplasm is a gel-like substance that fills the cell and is not directly responsible for protection, communication, or regulating substance passage.
What part of a light microscope is used to hold the slide in place?
- A. Stage clips
- B. Rack stop.
- C. Base.
- D. Arm.
Correct Answer: A
Rationale: