1.
Allows cell to maintain a favorable internal environment
Correct Answer
B. Selectively permeable
Explanation
The correct answer is selectively permeable. The term "selectively permeable" refers to the property of a membrane that allows certain substances to pass through while preventing others from doing so. In the context of a cell, a selectively permeable membrane allows the cell to control the movement of molecules and ions in and out of the cell. This helps maintain a favorable internal environment by regulating the entry and exit of substances such as nutrients, waste products, and ions.
2.
Movement of molecules from an area of high concentration to an area of low concentration.
Correct Answer
B. Diffusion
Explanation
Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration. It occurs due to the random motion of molecules. In this process, molecules spread out and become evenly distributed in a given space. Diffusion is a fundamental process in various biological and physical systems, such as the exchange of gases in the lungs and the movement of nutrients and waste products across cell membranes. It does not require any external energy input and continues until equilibrium is reached.
3.
Without the aid of a transport molecule (no energy)
Correct Answer
B. Passive diffusion
Explanation
Passive diffusion is the process by which molecules move across a phospholipid bilayer without the need for energy or the assistance of transport molecules. In this type of diffusion, molecules move from an area of higher concentration to an area of lower concentration, following the concentration gradient. The phospholipid bilayer acts as a barrier, allowing small, non-polar molecules to pass through easily, while larger or charged molecules may have more difficulty. Therefore, the given answer of "passive diffusion" is the correct explanation for the scenario described.
4.
Becomes a barrier to hydrophillic substances
Correct Answer
A. pHospHolipid Bilayer
Explanation
The phospholipid bilayer is a key component of cell membranes and acts as a barrier to hydrophilic substances. It consists of a double layer of phospholipids with hydrophilic heads facing outward and hydrophobic tails facing inward. This arrangement prevents the passage of hydrophilic substances through the membrane, while allowing the diffusion of small hydrophobic molecules. Therefore, the phospholipid bilayer selectively permits the movement of certain substances, making it selectively permeable.
5.
Involves passive diffusion(no energy) and facilitated diffusion(uses transport proteins)
Correct Answer
B. Passive Transport
Explanation
Passive transport refers to the movement of molecules across a cell membrane without the use of energy. It can occur through passive diffusion, where molecules move from an area of higher concentration to an area of lower concentration, and facilitated diffusion, where transport proteins assist in the movement of molecules across the membrane. In this case, the correct answer suggests that the process of passive transport involves both passive diffusion and facilitated diffusion, which accurately describes the movement of molecules across the cell membrane without the need for energy.
6.
Concentration of a solute is higher on one side of membrane and lower on the other side
Correct Answer
C. Transmembrane Gradient
Explanation
A transmembrane gradient refers to a difference in concentration of a solute across a membrane, where the concentration is higher on one side of the membrane and lower on the other side. This gradient is usually maintained through the use of transport proteins that allow the solute to move across the membrane, and it can also create osmotic pressure, which is the force exerted by the movement of water across the membrane to equalize the solute concentration. Therefore, the correct answer is transmembrane gradient.
7.
Channel Proteins, involves co-transporters
Correct Answer
A. Transport Proteins
Explanation
Transport proteins are involved in the process of moving molecules or ions across a membrane. They can facilitate the transport of substances by various mechanisms, including co-transporters. Co-transporters are a type of transport protein that work in conjunction with another molecule or ion to transport it across the membrane. Therefore, the given answer "Transport Proteins" is a valid explanation for the involvement of co-transporters in channel proteins.
8.
Binds 2 or more ions or molecules and transports them in the same direction
Correct Answer
A. Co-transporters
Explanation
Co-transporters are proteins that bind to multiple ions or molecules and transport them in the same direction. They work by utilizing the energy derived from another molecule or ion moving down its concentration gradient. This process is known as active transport. Therefore, co-transporters are a type of transport protein that actively moves substances across a cell membrane.
9.
Hydrostatic pressure required to stop the net flow of H20 across a membrane due to osmosis or diffusion of H2O across a membrane
Correct Answer
B. Osmotic pressure
Explanation
Osmotic pressure is the correct answer because it refers to the hydrostatic pressure required to stop the net flow of water across a membrane due to osmosis or diffusion. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semipermeable membrane. The osmotic pressure is the force that prevents the water molecules from moving across the membrane when the pressure is equal on both sides. Therefore, osmotic pressure is the appropriate term to describe the hydrostatic pressure required to stop the net flow of water in this context.
10.
These require energy and move against the concentration gradient.
Correct Answer
B. Active Transport
Explanation
Active transport is the correct answer because it is the process by which cells move molecules or ions across a cell membrane against the concentration gradient. Unlike passive transport, which does not require energy and moves molecules down the concentration gradient, active transport requires energy in the form of ATP to transport molecules or ions from an area of lower concentration to an area of higher concentration. This process is essential for maintaining the balance of substances within the cell and is often used to transport important molecules or ions that are needed in higher concentrations inside the cell.
11.
This has 2 layers of lipids, its amphipathic, and contains proteins and carbs attached to lipids and proteins.
Correct Answer
A. pHospHolipid bilayer
Explanation
The correct answer is the phospholipid bilayer. The phospholipid bilayer is composed of two layers of lipids, making it a bilayer. It is amphipathic because it has both hydrophilic and hydrophobic regions. Additionally, the phospholipid bilayer contains proteins and carbohydrates that are attached to both lipids and proteins.
12.
Mosaic of lipids, carbs, and proteins
Correct Answer
B. Membrane
Explanation
The correct answer is "Membrane". The given options describe different components and processes related to cellular membranes. The term "Mosaic" suggests that the membrane is made up of various components such as lipids, carbs, and proteins, which aligns with the Fluid Mosaic Model. Membranes play a crucial role in passive diffusion, which is the movement of molecules across the membrane without the need for energy expenditure. Therefore, the most appropriate answer is "Membrane".
13.
Accepted model of plasma membrane. It's the semifluid phospholipid bilayer and proteins.
Correct Answer
A. Fluid Mosaic Model
Explanation
The correct answer is the Fluid Mosaic Model. This model describes the structure of the plasma membrane as a semifluid phospholipid bilayer with embedded proteins. The phospholipid bilayer is fluid, allowing for the movement of molecules within the membrane. The proteins are scattered throughout the membrane, giving it a mosaic-like appearance. This model is widely accepted and supported by experimental evidence.