Nokea
What is the term for movement of water across a cellular membrane?
- A. Osmosis.
- B. Facilitated diffusion.
- C. Diffusion.
- D. Active transport.
Correct Answer: A
Rationale: Correct Answer: A - Osmosis
Rationale:
1. Osmosis is the movement of water across a selectively permeable membrane from an area of low solute concentration to high solute concentration.
2. Water moves passively to equalize solute concentrations on both sides of the membrane.
3. Facilitated diffusion (B) involves the use of transport proteins, not specific to water movement.
4. Diffusion (C) is the movement of solutes, not specific to water.
5. Active transport (D) requires energy to move molecules against their concentration gradient, different from osmosis.
You may also like to solve these questions
Which combination of cell cycle phase and descriptor is correct?
- A. S phase - the cell synthesizes DNA and doubles its cytoplasm
- B. G� phase - the amount of chromosomes is doubled
- C. GÄ‚‚ phase - the phase prior to the start of mitosis in which the cell continues to grow in size and make proteins
- D. Interphase - the cell increases in mass and number of organelles to prepare for cell division
Correct Answer: C
Rationale: The correct answer is C. The GÄ‚‚ phase is the phase before mitosis within interphase where the cell grows in size and synthesizes proteins needed for cell division. Option A incorrectly describes the S phase, which is primarily for DNA synthesis. Option B is incorrect as the doubling of chromosomes does not occur in GÄ‚� phase. Option D is inaccurate because interphase encompasses GÄ‚�, S, and GÄ‚‚ phases, during which the cell prepares for division by increasing its mass and organelles, rather than specifically focusing on mitosis preparation.
How are lipids different from other organic molecules?
- A. They are indivisible.
- B. They are not water-soluble.
- C. They contain zinc.
- D. They form long proteins.
Correct Answer: B
Rationale: Lipids are different from other organic molecules because they are not water-soluble, unlike carbohydrates and proteins. This property is due to their hydrophobic nature, which makes them insoluble in water but soluble in nonpolar solvents. Lipids play essential roles in energy storage, insulation, and cell membrane structure, making them distinct from other organic molecules. The statement 'They are indivisible' (Choice A) is not accurate as lipids can be broken down into fatty acids and glycerol. Choice C, 'They contain zinc,' is incorrect as lipids do not necessarily contain zinc. Choice D, 'They form long proteins,' is inaccurate as lipids do not form proteins; proteins are formed from amino acids.
Which term means alternate forms of a gene for the same trait?
- A. Phenotypes.
- B. Genotypes
- C. Alleles.
- D. Gametes.
Correct Answer: C
Rationale:
Which term means the movement of water across a semi-permeable membrane from a low solute concentration to a high solute concentration?
- A. Active Transport.
- B. Passive Transport.
- C. Osmosis.
- D. Diffusion.
Correct Answer: C
Rationale: The correct answer is C: Osmosis. Osmosis is the movement of water molecules across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. This process occurs passively, without the need for energy input.
Rationale:
1. Osmosis specifically refers to the movement of water molecules.
2. It occurs across a semi-permeable membrane.
3. The direction of movement is from low solute concentration to high solute concentration.
4. Osmosis is a passive transport process, as it does not require energy.
Summary:
A: Active Transport involves the movement of molecules against the concentration gradient, requiring energy input.
B: Passive Transport includes processes like diffusion and osmosis but does not involve active energy expenditure.
D: Diffusion is the movement of molecules from high concentration to low concentration, not specific to water movement across a membrane.
Why doesn't an antibiotic work for treating the flu symptoms in a patient?
- A. The antibiotic is for a different type of infection.
- B. The antibiotic is not effective against the flu virus.
- C. The antibiotic is not administered in a sufficient dosage to combat the flu.
- D. None of the above
Correct Answer: B
Rationale: Antibiotics are effective against bacterial infections, not viral infections like the flu. Influenza is caused by a virus, and antibiotics do not work against viruses. Using antibiotics inappropriately, such as for viral infections, can lead to antibiotic resistance and other adverse effects. Therefore, it is important to use antibiotics only when prescribed by a healthcare professional for bacterial infections.