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?

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

   Which side of the membrane has the higher concentration of oxygen now, Esme?

   • The membrane holds the most
   • Outside the cell
   • Inside the cell
   • Neither: the sides are even
4. 3.

   Which way will oxygen move across the membrane, Jun?

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

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

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

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

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

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

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

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

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

    • Yes: the membrane pulls it in
    • No: diffusion needs no energy from the cell
    • No: oxygen stays outside
    • Yes: the cell pumps it in
11. 9.

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

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

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

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