The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called
facilitated diffusion
endocytosis.
active transport
osmosis
diffusion
The Correct Answer is C
A. facilitated diffusion: Facilitated diffusion is the movement of substances across a cell membrane via specific carrier proteins or channels, but it occurs along the concentration gradient (from high to low) and does not require cellular energy. It relies on the natural kinetic energy of molecules rather than ATP.
B. endocytosis: Endocytosis involves the engulfing of large particles or liquids by the cell membrane to bring them into the cell. Although it requires energy, it is a bulk transport mechanism rather than the specific movement of molecules against a concentration gradient using a carrier protein.
C. active transport: Active transport is the movement of molecules against their concentration gradient (from lower to higher concentration) using specific transport proteins and energy expenditure, typically in the form of ATP. Examples include the sodium-potassium pump and calcium pumps in cell membranes, which maintain essential ionic gradients for cell function.
D. osmosis: Osmosis is the passive movement of water molecules across a semipermeable membrane from an area of low solute concentration to high solute concentration. It does not require energy or a carrier protein and is specific to water movement.
E. diffusion: Diffusion is the passive movement of molecules from an area of higher concentration to lower concentration down their concentration gradient. It does not require energy or proteins and is driven by molecular motion, unlike active transport which moves substances against the gradient.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
A. Lead: Lead is a heavy metal that has historical use in paints and plumbing but has limited antimicrobial properties. While toxic to humans and microbes at high concentrations, it is not commonly used as an effective antimicrobial agent in commercial products today due to safety concerns and poor efficacy compared with modern agents.
B. Carbohydrate: Carbohydrates serve primarily as nutrients and energy sources for organisms. They do not possess intrinsic antimicrobial properties and therefore are ineffective in killing microorganisms in commercial products.
C. Bacteriostatic: Bacteriostatic chemicals inhibit the growth and reproduction of microorganisms but do not directly kill them. These agents rely on the host immune system to eliminate the inhibited microbes. While useful, bacteriostatic agents are generally less immediately effective than bactericidal compounds when rapid microbial killing is desired.
D. Bactericidal: Bactericidal chemicals actively kill microorganisms by disrupting essential cellular structures or metabolic processes, such as the cell wall, cell membrane, or protein synthesis. Commercial products containing bactericidal agents, such as bleach, alcohol, and phenolic compounds, are more effective at eliminating microbial populations quickly and reducing the risk of infection.
Correct Answer is A
Explanation
A. Budding: Yeasts, which are unicellular fungi, primarily reproduce asexually through budding. In this process, a small protuberance forms on the parent cell, grows, and eventually detaches to become a new independent cell. Budding allows rapid population growth and is a hallmark characteristic of organisms like Saccharomyces cerevisiae.
B. Binary fission: Binary fission is the primary method of reproduction for most prokaryotic organisms, such as bacteria, in which a single cell divides into two genetically identical daughter cells. While yeasts can undergo mitotic divisions, budding is their main asexual reproductive mechanism.
C. Conjugation: Conjugation is a form of genetic recombination seen in some bacteria and protozoa, involving the transfer of genetic material between two cells. Yeasts generally do not use conjugation as their primary reproductive strategy, although sexual reproduction via mating types can occur under certain conditions.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.