Cells are the basic structural and functional units of life. They were first discovered by Robert Hooke in 1665 when observing cells in a piece of cork under a microscope. Cells come in two main types - prokaryotic and eukaryotic. Cells can be either unicellular or multicellular. In humans, there are over 200 types of cells and the total number of cells is around 100 trillion. Cells are the building blocks that make up tissues, organs, organ systems and entire organisms.

1. Cell
As a basic unit of life

2. Cell
Basic structural and functional unit of life
Bound by a cell membrane
Perform essential functions of life

3. Intro
Cell are found in all the organisms complex than viruses.
Virus lack cell like structure - noncellular
Discovered by ROBERT HOOKE (1665) - cells in piece of cork and published his
findings in Micrographia. Those were dead cells with honey-comb structure
ANTON VAN LEEUWENHOEK - observed live cells and named them animalcules
(little animals)

4. Cells
Prokaryotic Eukaryotic
Cytology - study of forms and structure of the cells as well as their
organelles with the help of microscope
Cell biology - study of structure, biochemistry, physiology, reproduction,
evolution and genetics of cell

5. ORGANISMS
UNICELLUALR MULTICELLULAR
ANIMALS
PLANTSCHLAMYDOMONAS
AMOEBA

6. HUMAN200 TYPES OF CELLS
100 TRILLION CELLS

7. Cell
Building block

8. “Any living cell carries with it the experience of a billion years of experimentation
by its ancestors. (1949) ”
- Max Ludwig Henning Delbrück

9. Cell are organised as tissues (group of cells having common origin and common function)
Animals - 4 types - epithelial, connective, muscular, nervous
Plants - simple - parenchyma, collenchyma, sclerenchyma
Organ - complex structure formed by association of two or more tissues specialised to perfom a
function
Organ system - organs coordinate to perform a specific function
Organism - integrated unit of organ systems

10. Thanks!