Unit 3 Cell Transport

Elizabeth is investigating how molecules are transported into and out of a cell. Elizabeth builds a model of a cell using a U-shaped tube. A barrier, which is permeable to water, but not sugar, is placed on the bottom of the tube to model the cell membrane. Elizabeth adds two different solutions to each side of the tube. The solute in each solution is sugar and the solvent is water. The initial levels of solution in Side A and Side B are equal. The concentration of sugar in Side A is lower than the concentration of sugar in Side B.

What is Elizabeth likely to observe?

• Water molecules will move from Side B to Side A. The solution level on Side A will rise and the solution level on Side B will fall.

• Water molecules will move from Side A to Side B. The solution level on Side A will fall and the solution level on Side B will rise.

• Sugar molecules will move from Side A to Side B. The solution level on Side A will fall and the solution level on Side B will rise.

• Sugar molecules will move from Side B to Side A. The solution level on Side B will rise and the solution level on Side A will fall.

Answer explanation

Solutes will not move past the semi-permeable membrane. The water moves from an area of lower concentration to an area of higher concentration to obtain equilibrium. This will cause the level to rise on side B.

Tags

NGSS.HS-LS2-3

Osmosis, Diffusion and Facilitated Diffusion are all examples of _ _ _ _ _ _ _ transport.

Protein Pump, Exocytosis and Endocytosis are all examples of _ _ _ _ _ _ _ transport.

Wes places red blood cells in a petri dish with pure water and observes them under a microscope. Based on the image, what is the most likely explanation for Wes’s observations?

• The red blood cells were placed in a hypotonic solution. Water moved from the outside of the cells to the inside of the cells until the cells burst.

• The red blood cells were placed in a hypertonic solution. Water moved from the inside of the cells to the outside of the cells to maintain homeostasis.

• The red blood cells were placed into an isotonic solution. Water moved into and out of the cells to maintain homeostasis.

• The red blood cells were placed into an isotonic solution. Water moved into the cells until the cells burst.
  

Tags

NGSS.HS-LS1-3

The movement of matter across a cell membrane against a concentration difference (LOW TO HIGH) is called __________transport, and it requires __________.

• Active, No ATP (no energy)

• Passive, No ATP (no energy)

• Active, ATP (energy)

• Passive, ATP (energy)

The movement of matter across a cell membrane with a concentration difference (HIGH TO LOW) is called ___________ transport, and requires ____________

• Active, No ATP (no energy)

• Passive, No ATP (no energy)

• Active, ATP (energy)

• Passive, ATP (energy)

The model illustrates a process by which a substance is taken up by a cell.

Which statements describe the process?

Endocytosis, Pinocytosis, Osmosis, Exocytosis

Answer explanation

The correct choice is Endocytosis, which describes the process of a substance being taken up by a cell. Pinocytosis is a type of endocytosis for liquids, while osmosis refers to water movement, and exocytosis is the release of substances.

An investigation was set up to test different types of solutions on red blood cells. Which beaker shows a hypotonic environment?

• 1

• 2

• 3

• None

Tags

NGSS.HS-LS1-3

An investigation was set up to test different types of solutions on red blood cells. Which beaker shows the cells in a hypotonic state?

• 1

• 2

• 3

• None

Tags

NGSS.HS-LS1-3

An investigation was set up to test different types of solutions on red blood cells. Which beaker shows the cells in a hypertonic state?

• 1

• 2

• 3

• None

Tags

NGSS.HS-LS1-3