Homeostasis and the Cell

Elizabeth is conducting an investigation to study 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.

• 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.

• 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.

• 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 A will rise and the solution level on Side B will fall.

Tags

NGSS.HS-LS2-3

NGSS.HS-LS2-4

Classify diffusion as active or passive transport.

• active transport

• passive transport

Classify endocytosis as active or passive transport.

• active transport

• passive transport

Classify exocytosis as active or passive transport.

• active transport

• passive transport

Classify facilitated diffusion as active or passive transport.

• active transport

• passive transport

Classify osmosis as active or passive transport.

• active transport

• passive transport

Wes places red blood cells in a petri dish with pure water and observes them under a microscope. He drew a model to illustrate his observations. What is the most likely explanation for Wes’s observations?

• 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.

• 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 in a hypotonic solution. Water moved from the outside of the cells to the inside of the cells until the cells burst.

Tags

NGSS.HS-LS1-3

The pancreas produces enzymes that aid in digestion. By what process are these digestive enzymes excreted from pancreas cells?

• osmosis

• exocytosis

• endocytosis

• diffusion

The movement of matter across a cell membrane against a concentration difference is called ______________.

• passive transport

• osmosis

• active transport

• facilitated diffusion

The movement of matter across a cell membrane against a concentration difference is called active transport, and it requires _________.

• energy

• osmotic pressure

• aquaporins

• homeostasis