1.
The cell wall prevents a plant cell from bursting when placed in distilled water.
Correct Answer
A. True
Explanation
The cell wall is a rigid structure surrounding the cell membrane in plant cells. It provides support and protection to the cell. When a plant cell is placed in distilled water, the water concentration outside the cell is higher than inside the cell, causing water to enter the cell by osmosis. The cell wall prevents the cell from bursting by exerting an outward pressure on the cell membrane, maintaining the shape and integrity of the cell. Therefore, the statement is true.
2.
If a cell is placed in salt water, water will:
Correct Answer
A. Leave the cell and the cytoplasm and cell membrane shrink.
Explanation
When a cell is placed in salt water, the water concentration inside the cell is higher than outside. As a result, water molecules move out of the cell through osmosis, causing the cell to shrink. This process is known as plasmolysis. The salt water creates a hypertonic environment, where the concentration of solutes is higher outside the cell compared to inside. This causes water to leave the cell, resulting in the shrinking of the cytoplasm and cell membrane. Therefore, the correct answer is that water will leave the cell and the cytoplasm and cell membrane will shrink.
3.
What is true about osmosis?
Correct Answer
C. Both A and B
Explanation
Osmosis is the process by which water molecules move from an area of higher concentration to an area of lower concentration through a semi-permeable membrane. This movement occurs passively, meaning it does not require any energy input. Therefore, the correct answer is both A and B, as osmosis involves the diffusion of water through a semi-permeable membrane and is a passive process.
4.
When the amount of water in a cell is higher than the amount of solute in a cell it is _______.
Correct Answer
hypotonic
Explanation
When the amount of water in a cell is higher than the amount of solute in a cell, the solution is hypotonic. In a hypotonic solution, the concentration of solute is lower inside the cell compared to the surrounding environment. This causes water to move into the cell through osmosis, leading to cell swelling or potential lysis if the excess water is not regulated.
5.
What is active transport?
Correct Answer
C. Movement of molecules across a semi-permeable membrane against a concentration gradient that requires energy
Explanation
Active transport is the movement of molecules across a semi-permeable membrane against a concentration gradient with the help of a protein. Unlike passive transport, active transport requires energy to pump molecules from an area of lower concentration to an area of higher concentration. This process is essential for maintaining proper cellular function and is often used to transport ions and other molecules that are needed in higher concentrations inside the cell.
6.
How is isotonic defined?
Correct Answer
C. When the amount of water and solute in a cell are at equilibrium.
Explanation
Isotonic is defined as a state in which the amount of water and solute in a cell are at equilibrium. In an isotonic solution, the concentration of solutes outside the cell is the same as the concentration inside the cell, resulting in no net movement of water across the cell membrane. This means that the cell neither gains nor loses water, maintaining its normal shape and function.
7.
What is movement in diffusion based on?
Correct Answer
C. Movement is based on kinetic energy (speed), charge, and mass of molecules.
Explanation
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. This movement is driven by the kinetic energy, charge, and mass of the molecules. The molecules are in constant motion due to their kinetic energy, and this random motion causes them to spread out and mix with other molecules. The charge and mass of the molecules also play a role in determining the rate and direction of diffusion. Therefore, movement in diffusion is based on the kinetic energy, charge, and mass of the molecules involved.
8.
Describe a cell that is in an isotonic environment.
Correct Answer
B. A cell that has an equilibrium of water to solute.
Explanation
A cell that is in an isotonic environment is one where the amount of water and solute in the cell are at equilibrium. In other words, there is an equal concentration of water and solute inside the cell. This means that there is no net movement of water into or out of the cell, as the concentration is balanced.
9.
In a solution, salt is considered the solute.
Correct Answer
A. True
Explanation
In a solution, the solute is the substance that is dissolved in the solvent. Since salt is the substance that is being dissolved in the solution, it is considered the solute.
10.
There are _____ types of osmotic conditions.
Correct Answer
3, three
Explanation
The question asks for the number of types of osmotic conditions. The answer is 3 or three. This means that there are three different types of osmotic conditions.