Chapter 3 Section 2 The Cell In Its Environment

Question 1

All cells are surrounded by a _______. These are said to be ________. The exchange of materials between a cell and its environment takes place at the cell membrane.

Answer 1

Cell membrane

Selectively permeable

Question 2

What does selectively permeable mean?

Answer 2

the pores in the cell membrane allow only certain particles to pass in and out of the cell

Question 3

Define Diffusion

Answer 3

the process in which small particles move across a selectively permeable membrane from an area of high concentration to an area of low concentration using no energy

Question 4

is energy needed for diffusion

Answer 4

no

Question 5

in what direction do molecules move during diffusion

Answer 5

high to low

Question 6

suppose a permeable membrane separates sugar solutions with concentrations of 5g/L and 7 g/L. Which way will the sugar diffuse across the membrane?

Answer 6

the sugar will move from an area of high concentration (7) to an area of low concentration (5)

Question 7

_____ is the diffusion of water molecules through a selectively permeable membrane

Answer 7

osmosis

Question 8

cells cannot function properly without an adequate supply of ____. this is why osmosis is important

Answer 8

water

Question 9

if a plant is wilted, then I water it, what is the result of the plant and why is this happening?

Answer 9

the water is pulled from the roots to the cell. the water fills the vacuole and the plant become firm again. this is the process of osmosis.

Question 10

moving small particles can be done in 2 ways. What are those ways? Do they require energy?

Answer 10

Active and Passive Transport. Energy is required for active. Energy is not required for passive.

Question 11

Give 2 examples of passive transport. Give examples of substances being moved.

Answer 11

passive transport is diffusion and osmosis

examples of what is being moved: oxygen, water

Question 12

Describe active transport. Give examples of substances being moved.

Answer 12

active transport is the process in which particles move across a selectively permeable membrane from an area of low concentration to an area of high concentration using energy.

Question 13

Moving large particles can be done in 2 ways - what are they? (both active)

Answer 13

Endocytosis and exocytosis

Question 14

Explain the process of endocytosis and exocytosis. Give examples of what is being moved.

Answer 14

See worksheet? Protein and single cell organisms are what is being moved.