Cells need to bring in molecules to carry out cellular processes. Often, this requires moving the molecules across the cell membrane against the concentration gradient. How do these molecules get into the cell?
passive transport by diffusion
active transport using ATP
passive transport by osmosis
osmosis
2. Multiple Choice
1.5 minutes
1 pt
A person with swollen gums rinses his mouth with warm salt water, and the swelling decreases. Which of the following has occurred?
The swollen gums have absorbed the saltwater solution.
The saltwater solution lowers the temperature of the water in the gums.
The salt in the solution has moved against the concentration gradient.
The water in the gums has moved out due to the high concentration of salt in the solution.
3. Multiple Choice
30 seconds
1 pt
The cell membrane of the red blood cell will allow water, oxygen, and carbon dioxide to pass through. Because other substances are blocked from entering, this membrane is called
perforated
semi-permeable
non-conducive
permeable
4. Multiple Choice
30 seconds
1 pt
Look at the diagram of a cross-section of a cell membrane below. The cell membrane controls movement of materials into and out of the cell. The following particles are moving from high concentration to low concentration and are using a carrier protein. How would you describe this type of movement across the membrane?
simple osmosis
active transport
simple diffusion
facilitated diffusion
5. Multiple Choice
30 seconds
1 pt
Look at the cross section of a cell membrane of a eukaryotic cell. H+ ions are being pumped from a low concentration to a high concentration. How do you describe this type of transport across the cell membrane?
active transport
passive transport
facilitated diffusion
co-transport
6. Multiple Choice
20 seconds
1 pt
In pure water, a red blood cell from an animal will swell and burst, but a leaf cell from a plant will not. Which structure in the leaf cell is responsible for this difference?
cell membrane
cell wall
mitochondrion
nucleus
7. Multiple Choice
1.5 minutes
1 pt
The diagram below represents a cell and some molecules in its environment. Which molecule would require the use of energy in order to be brought into the cell?
1
2
3
4
8. Multiple Choice
30 seconds
1 pt
Which activity can occur without the use of energy?
contraction of muscle tissue
protein synthesis in a cell
active transport of minerals
movement of water across a membrane
9. Multiple Choice
30 seconds
1 pt
The diffusion of water across a selectively permeable membrane is called
active transport
facilitated diffusion
osmosis
phagocytosis
10. Multiple Choice
30 seconds
1 pt
During diffusion molecules tend to move
up the concentration gradient
from an area of lower concentration to an area of higher concentration
in a direction that doesn’t depend on concentration