Diffusion and Osmosis Midterm Test
The process of bringing in particles to the cell is called:
Endocytosis
Molecules will move until ________________ is reached.
Equilibrium
The process of taking particles out of the cell is called:
Exocytosis
One student compares the cell membrane to a solid brick wall encasing the cell. A second student compares the cell membrane to a fence with several gates encasing the cell. Which student's analogy is a better representation of the cell membrane?
Fence with gates; the cell membrane allows particles to diffuse or travel through designated areas.
What describes hypotonic solutions?
Has a higher concentration of water and a lower concentration of solutes than another solution
If a red blood cell is placed in a solution that has a concentration gradient higher than the red blood cell, this type of solution is called.
Hypertonic
An experiment is designed to study osmosis. For the experiment, three same-size eggs are placed in three different beakers each containing 250 mL of water with varying salinity. All three breakers are undisturbed for 24 hours. The mass of each egg before and after completion of the experiment is recorded to compare the movement of water into the eggs. Which hypothesis is the experiment designed to test?
If eggs are immersed in water with varying salinities, the concentrations of solute will determine the rate of osmosis across the eggs' membranes.
Which way will water molecules move if a red blood cell is placed in distilled water?
Into the red blood cell
A solution in which the concentration of solutes is the same inside and outside of a cell is a ____________________ solution.
Isotonic
Because the human body is 60% water, an important process which helps humans and all living things maintain a "normal" internal cellular environment even when external surroundings are constantly changing is: ___________________
Osmosis
If water molecules move across a cell membrane, what cellular process is being represented?
Osmosis
To investigate the effect of salt water on a cell, a researcher places one cell sample in freshwater and a second cell sample in salt water. What change in the cells occurred during the six hours the cells remained undisturbed?
Osmosis occurred in the salt water cell sample because the water from inside the cell moved out of the cell to a lower concentration, causing the cell to shrink.
Which statement is true about passive transport?
Particles move from an area of high concentration to low concentration.
Why does water (H2O) cross the cell membrane without help, but sugar (C6H12O6) requires special structures to cross the membrane?
Sugar molecules are too large to enter by diffusion.
The diagram illustrates a cell membrane regulating passage of essential nutrients. Which property of the membrane is most closely associated with its ability to promote this process?
The cell membrane is selectively permeable, ensuring regulated passage of nutrients.
A cell is placed in a salt solution that has the same concentration as the inside of the cell. What will happen to the cell?
The cell will remain the same size.
The diagram shows oxygen moving into an animal cell. Which statement best describes the cell after this process has occurred?
The concentration of oxygen inside and outside the cell will be nearly equal.
If an egg soaked in vinegar for two days then salt water for two days, what factor explains why the egg's size changed during the experiment?
The egg was selectively permeable, and liquids diffused in and out of the egg.
Which diagram accurately shows the process of simple diffusion?
The molecules are moving upward high to low concentration
A student performs an activity in which a soluble colored substance is dropped in a beaker filled with water, as shown in the figure. Which statement explains why the water in the beaker is a uniform color after a period of time?
The molecules of the colored substance move randomly through the water, with the majority moving from an area of high concentration to an area of low concentration.
The diagram shows a cell surrounded by nutrients. Which statement most accurately describes the movement of nutrients by diffusion?
The nutrients will move INTO the cell across the cell membrane
A student places a drop of food coloring in a beaker of water and draws how the water and food coloring particles are arranged, as shown. After one hour, the student again draws how the particles of water and food coloring are arranged. Which model does the student most likely draw?
The particles of water and food coloring are evenly distributed.
Which statement describes how wastes are eliminated from cells?
Waste particles are eliminated by the process of diffusion as they move from areas of high to low concentration.
What demonstration best illustrates simple diffusion?
adding a drop of food coloring into a glass of water
A large starch molecule attempts to enter a cell. Which structure would control the entrance of the molecule into the cell?
cell membrane
The movement of molecules from a place where there is greater/higher concentration to an area where there is ___________
definition of diffusion
The diagram shows oxygen moving into an animal cell. Which term best describes this process?
diffusion
What is the role of simple diffusion in a cell?
maintains equal concentrations of substances inside and outside the cell
The cell membrane allows some molecules such as oxygen and water to enter the cell but prevents other substances from entering the cell. What term best describes the cell membrane?
selectively permeable
Which substance is critical in maintaining the osmotic pressure in a plant cell?
water
