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?

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

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

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

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

   • Outside the cell
   • Inside the cell
   • The membrane holds the most
   • Neither: the sides are even
5. 4.

   Which way will oxygen move across the membrane, Jun?

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

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?

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

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

   • From higher to lower concentration
   • Toward the membrane
   • From lower to higher concentration
   • From the top of the cell to the bottom
9. 7.

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

   • It makes the cell's food
   • It blocks oxygen from entering
   • It holds the cell's DNA
   • It controls what goes in and out
10. 8.

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

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

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

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

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

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