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.

3. 1.

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

   • The two sides are even
   • Outside the cell
   • Inside the cell
   • The membrane itself
4. 2.

   Which way will oxygen move across the membrane, Jun?

   Use the picture in question 1.

   • It won't cross the membrane
   • Out of the cell
   • Into the cell
   • Into the membrane, where it stays
5. 3.

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

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

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. 4.

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

   • Into the leaf cell
   • Out into the air space
   • Nowhere: leaves keep their oxygen
   • Down into the roots
8. 5.

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

   • Particles being pumped by the cell
   • Particles spreading from more crowded to less crowded
   • Particles turning into new ones
   • Particles gathering where they are already crowded
9. 6.

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

   • From higher to lower concentration
   • From the top of the cell to the bottom
   • From lower to higher concentration
   • Toward the membrane
10. 7.

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

    • It holds the cell's DNA
    • It blocks oxygen from entering
    • It makes the cell's food
    • It controls what goes in and out
11. 8.

    Does a cell spend energy to move oxygen in by diffusion, Ren?

    • Yes: the membrane pulls it in
    • No: oxygen stays outside
    • No: diffusion needs no energy from the cell
    • Yes: the cell pumps it in
12. 9.

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

    • Gravity drops them through
    • Empty space pulls them
    • The cell pushes them along
    • They keep moving at random
13. 10.

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

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