Back to Course

SS1: BIOLOGY - 1ST TERM

0% Complete
0/0 Steps
  1. Introduction to Biology | Week 1
    6 Topics
    |
    1 Quiz
  2. Recognizing Living Things | Week 2
    3 Topics
    |
    1 Quiz
  3. Organisation of Life | Week 3
    3 Topics
  4. Classification of Living Organisms | Week 4
    7 Topics
    |
    1 Quiz
  5. Kingdom Prokaryotae / Monera & Kingdom Protista | Week 5
    3 Topics
    |
    3 Quizzes
  6. Kingdom Fungi & Kingdom Plantae | Week 6
    9 Topics
    |
    2 Quizzes
  7. Kingdom Animalia I | Week 7
    6 Topics
    |
    1 Quiz
  8. Kingdom Animalia II | Week 8
    5 Topics
    |
    1 Quiz
  9. The Cell | Week 9
    3 Topics
    |
    1 Quiz
  10. The Cell Structure and Functions | Week 10
    4 Topics
    |
    1 Quiz
  11. The Cell and its Environment | Week 11
    4 Topics
    |
    1 Quiz
  12. Nutrition in Plants | Week 12
    4 Topics
    |
    1 Quiz



  • Do you like this content?

  • Follow us

Lesson 9, Topic 3
In Progress

Cell Theory

Lesson Progress
0% Complete

Contributions to the Cell Theory (History of cells):

(i) Robert Hooke (An English Botanist) 1665:

In a 1665 publication called Micrographia, Robert Hooke coined the term “cell” for the box-like structures he observed when viewing cork tissue through a lens.

(ii) Felix Dujardin (French Biologist) 1835:

  • He discovered that cells are made up of living substances which he named protoplasm.

(iii) Matthias Schleiden (German Botanist) 1838:

  • He revealed that the bodies of plants are made up of cells. He defined the cell as the basic unit of plant structure.

(iv) Theodore Schwann 1839 – (German Zoologist):

  • All animals’ bodies are composed of cells. He defined the cell as the basic unit of animal structure.
  • The discoveries of Schleiden and Schwann led to the formulation of cell theory.

(v) Rudulf Virchow (German Biologist) 1855:

  • He concluded in his research that all cells only arise from pre-existing cells. This led to bio-genesis.
  • The biologist also realized that cells are not only the structural but also functional unit of life of living organisms.

The Cell theory states that:

i. The cell is the fundamental unit of structure and function in living things.

ii. All organisms are made up of one or more cells.

iii. All cells arise from pre-existing cells through cellular division.

The expanded version of cell theory can also include;

  • Cells carry genetic material passed to daughter cells during cellular division.
  • All cells are essentially the same in chemical composition.
  • Energy flow (metabolism and biochemistry) occurs within cells.

Responses

Your email address will not be published.

back-to-top
error: