Diffusion across a cell membrane

Grade 7 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Cell arrow diagram (model data, not to scale). No arrows are drawn yet.

2. 1.

   Which side of the membrane has the higher concentration of oxygen, Ari?

   • Inside the cell
   • Outside the cell
   • The membrane itself
   • The two sides are even
3. 2.

   Which side of the membrane has the higher concentration of carbon dioxide, Bo?

   • The two sides are even
   • Inside the cell
   • Outside the cell
   • Neither side has any
4. 3.

   Which way will oxygen move across the membrane, Jun?

   • It won't cross the membrane
   • Into the membrane, where it stays
   • Into the cell
   • Out of the cell
5. 4.

   Which way will carbon dioxide move across the membrane, Kira?

   • Into the nucleus
   • Out of the cell
   • Into the cell
   • It stays where it is

6. Use this

   Leaf cell arrow diagram (model data, not to scale). Boxes: air space in the leaf, with 2 oxygen dots; inside the leaf cell, with 9 oxygen dots. The cell membrane is between them, and both boxes are the same size. No arrows are drawn yet.

7. 5.

   In sunlight, a leaf cell makes oxygen. Which way will that oxygen move, Luz?

   • Out into the air space
   • Into the leaf cell
   • Nowhere: leaves keep their oxygen
   • Down into the roots
8. 6.

   Milo reads the word diffusion in a science book. What does it mean?

   • Particles turning into new ones
   • Particles being pumped by the cell
   • Particles spreading from more crowded to less crowded
   • Particles gathering where they are already crowded
9. 7.

   Noah reads that particles move down their concentration gradient. Which way is that?

   • Toward the membrane
   • From lower to higher concentration
   • From the top of the cell to the bottom
   • From higher to lower concentration
10. 8.

    A cell membrane works a bit like a door with rules. What is its job, Pia?

    • It controls what goes in and out
    • It makes the cell's food
    • It blocks oxygen from entering
    • It holds the cell's DNA
11. 9.

    Why do particles spread out across a membrane on their own, Tala?

    • Gravity drops them through
    • They keep moving at random
    • Empty space pulls them
    • The cell pushes them along
12. 10.

    Diffusion is a kind of passive transport. What does passive mean here, Zee?

    • It happens just in plants
    • The cell spends energy on it
    • It moves particles from fewer to more
    • It needs no energy from the cell