9th grade Cell theory and how it was discovered worksheet

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: Schleiden says plants are made of cells (1838). B: Hooke names cells in cork (1665). C: Virchow publishes an essay saying that cells come from cells (1855). D: Schwann says animals are made of cells (1839).

2. 1.

   Ari puts four cell-theory events on a timeline, earliest first. Which order is right?

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

3. 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).

4. 2.

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

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

5. 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).

6. 3.

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

   • C, D, B, A
   • C, A, D, B
   • D, C, A, B
   • C, D, A, B
7. 4.

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

   • Finished cell theory without any help
   • Showed that cells come from other cells
   • Named the box-like cork structures cells
   • Saw single-celled organisms in lake water
8. 5.

   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
   • Plant tissue that he described as made up of cells
   • Single-celled organisms he called animalcules
   • A finished cell theory he wrote himself
9. 6.

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

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

10. 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.

11. 7.

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

    • Part 3: new cells arise from existing cells
    • Part 1: one or more cells make up living things
    • Part 2: the cell is the basic living unit
    • Part 3: new cells form from nonliving matter
12. 8.

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

    • From damp air with no cells in it
    • From the bread itself turning into new cells
    • From the scientist who named cells
    • From mold cells that already existed
13. 9.

    Ren reads that cell theory is a scientific theory. What does theory mean in science?

    • A single observation made once
    • A guess that has not yet been tested
    • A tested and confirmed explanation
    • A rule that cannot change
14. 10.

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

    • A measurement
    • A theory
    • A hypothesis
    • A fact