Living Environment Regents Diffusion

molecules small enough to pass through the pores of cell membranes can passively leave the digestive system and enter the blood through what process?

• diffusion

• active transport

• photosynthesis

• cellular respiration

The diagram shows an experimental setup using an artificial plant cell. Molecules A and B are commonly found in plant cells. When tested, it was discovered that molecule A quickly passed through the artificial plant cell membrane. Molecule B did not pass through. The locations of molecules A and B at the beginning of the experiment are shown. Which statement best describes what was observed when the setup was examined 20 minutes later?

• Molecule A remained inside the artificial cell and molecule B remained outside.

• Only molecule A was found both inside and outside the artificial cell.

• Only molecule B was found both inside and outside the artificial cell.

• Both molecules A and B were found inside and outside the artificial cell.

Tags

NGSS.MS-LS1-2

Cell membranes are said to be selectively permeable. Which statement best explains what selectively permeable means?

• The cell membrane prevents any harmful substance from entering the cell.

• The cell membrane lets certain substances enter the cell and keeps certain substances out of the cell.

• The cell membrane allows only large molecules to diffuse into the cell.

• The cell membrane has pores that let only water and glucose into the cell and carbon dioxide out.

The diagram below represents a laboratory experiment involving sucrose and water molecules in a cellophane bag which functions in the same way as dialysis tubing.

Which statement correctly explains the rise of liquid in the tube at the end of the experiment?

• The concentration of sucrose molecules increased as water molecules entered the bag. This concentration

  increase pushed the liquid up the tube.

• Water entered the bag due to the lower concentration of water inside. The extra water pushed the liquid

  up the tube as the bag filled.

• Sucrose indicator entered the bag and reacted with the sucrose molecules. The reaction made the bag

  increase in size and pushed the liquid up the tube.

• Sucrose molecules moved out of the bag and up the tube while water moved out, causing the rise of

  liquid in the tube

Tags

NGSS.MS-LS1-2

The processes of diffusion and active transport

are both used to

• move molecules against a concentration

  gradient, using ATP molecules

• bring molecules into cells when they are

  more concentrated outside of the cell

• move molecules into or out of cells of the

  body

• break down molecules to release energy

Tags

NGSS.HS-LS2-3

Which dissolved substance do aquatic animals

remove from their external environment for use

in cellular respiration?

• carbon dioxide

• oxygen molecules

• ATP molecules

• nitrogen gas

Tags

NGSS.MS-LS2-1

Which procedure is represented in the diagram?

• making an artificial cell

• adding distilled water to the top of a cover glass on a slide

• adding salt solution to a specimen under the cover glass

• making a thin sample to prepare a slide of red onion cells

State one way the two molecules could differ that would explain the difference in their ability to pass through

the artificial plant cell membrane.

Answer explanation

— Molecule A is smaller than molecule B.

— Molecule B has an electrical charge.

— They could be different sizes.

— size of the molecule

— One is a sugar/monosaccharide and the other is a starch/polysaccharide.

Identify the process responsible for the effect that the salt water had on the plants _______________

Tags

NGSS.MS-LS1-2

Explain why glucose molecules can cross a cell membrane and starch molecules can not.

Tags

NGSS.MS-LS1-2