Cell theory and how it was discovered

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Four event cards, not in order. A: Remak shows that cells come from cells by dividing (1852). B: Leeuwenhoek sees single-celled organisms in lake water (1674). C: Schwann says animals are made of cells (1839). D: Hooke names cells in cork (1665).

2. 1.

   Bo sorts four more events from earliest to latest. Which order is right?

   • D, C, B, A
   • D, B, C, A
   • B, D, C, A
   • D, B, A, C

3. Use this

   Four event cards, not in order. A: Virchow publishes an essay saying that cells come from cells (1855). B: Pasteur disproves spontaneous generation with a flask experiment (1862). C: Leeuwenhoek sees single-celled organisms in lake water (1674). D: Schleiden says plants are made of cells (1838).

4. 2.

   Esme lines up another set of events, earliest first. Which order is right?

   • C, A, D, B
   • C, D, A, B
   • D, C, A, B
   • C, D, B, A
5. 3.

   Jun reads that Robert Hooke looked at thin slices of cork in the 1665 book Micrographia. What did Hooke do?

   • Showed that cells come from other cells
   • Named the box-like cork structures cells
   • Saw single-celled organisms in lake water
   • Finished cell theory without any help
6. 4.

   A Dutch shopkeeper, Antony van Leeuwenhoek, made single-lens microscopes. Kira reads that Leeuwenhoek looked at lake water in 1674. What did Leeuwenhoek see?

   • Box-like cork walls he named cells
   • A finished cell theory he wrote himself
   • Plant tissue that he described as made up of cells
   • Single-celled organisms he called animalcules
7. 5.

   Luz reads about the botanist Matthias Schleiden, who studied plant tissue under a microscope. What did Schleiden describe in 1838?

   • Single-celled organisms in lake water
   • New cells arise from older cells
   • A complete theory with no help from anyone
   • Plants are made of cells
8. 6.

   Milo lists some ideas about cells. Which idea is part of cell theory?

   • One scientist alone worked out the theory
   • Just plants are made of cells
   • Living things are made of one or more cells
   • New cells form from soil and water, with no cells needed

9. Use this

   Cell theory card. Part 1: one or more cells make up all living things. Part 2: the cell is the basic living unit. Part 3: new cells arise from existing cells.

10. 7.

    Noah reads the cell theory card. Which part tells where new cells come from?

    • Part 2: the cell is the basic living unit
    • Part 3: new cells arise from existing cells
    • Part 3: new cells form from nonliving matter
    • Part 1: one or more cells make up living things
11. 8.

    Pia sees mold spread across stale bread. By cell theory, where did the new mold cells come from?

    • From the bread itself turning into new cells
    • From mold cells that already existed
    • From damp air with no cells in it
    • From the scientist who named cells
12. 9.

    Tala reads that a suggested explanation for an observation, one that can be tested, has a name. What is it?

    • A hypothesis
    • A fact
    • A measurement
    • A theory
13. 10.

    Zee reads that every microscope has a resolving power. What is resolving power?

    • Keeping a living specimen alive on the glass slide
    • Showing two close structures as separate
    • Making the image look bigger
    • Lighting the slide from below