BIOL 5 - LESSON 3-a: CELLS

Cell

Cell

• It is the basic structural and functional unit of living organisms. 

• It makes up living things and carries out activities that keep them alive. 

Robert Hooke (1665)

Discovered cell

Anton Van Leeuwenhoek (1674)

Observed living cell

Robert Brown (1831)

Discovered nucleus

Felix Dujardin (1835)

Discovered fluid content of cell

Matthias Schleiden (1838)

Proposed all plants are made up of cells

J.E. Purkinje (1839)

Named fluid content of cell as protoplasm

Theodor Schwann (1839)

Proposed all animals are made up of cells

Carl Heinrich Braun (1845)

Proposed cell is the basic unit of life

Rudolf Virchow (1855)

Proposed all cells arise from pre-existing cells

Modern Cell Theory

A collection of ideas and conclusions from many different scientists over time that describes cells and how cell separate.

one or more

Modern Cell Theory no. 1

All known living things comprise ??? cells.

pre-existing

Modern Cell Theory no. 2
All living cells arise from ??? cells by division.

basic unit

Modern Cell Theory no. 3
The cell is the ??? of structure and function in all living organisms.

DNA

Modern Cell Theory no. 4
??? is passed between cells during cell division.

similar species

Modern Cell Theory no. 5
Cells of all organisms within a ??? are mostly the same

Energy

Modern Cell Theory no. 6
??? flow occurs within the cell.

Unicellular Organisms

• An organism that is made up of only one cell.

• Bacterium, Amoeba, Yeast 

Multicellular Organisms

• An organism comprising more than one cell.

• Plants, Animals, Insects

microscopic; macroscopic

Size of Cells
Most cells are very small (???), and some may be very large (???).

micrometer (1 μm = 1/1000 millimeter)

Size of Cells
The unit used to measure the size of a cell is?

Mycoplasma (0.1 μm)

Size of Cells
what is the smallest cell and its size?

Ostrich egg (18 cm)

Size of Cells
what is the largest cell and its size?

Sperm Cell (smallest - 5 μm)

Size of Cells
what is the smallest cells in human and its size?

Ovum cell (largest - 120 μm)

Size of Cells
what is the largest cells in human and its size?

Nerve cell (longest - 1 m)

Size of Cells
what is the longest cells in human and its size?

RBCs; circular biconcaves

Shape of cells
Human ??? are ??? for easy passage through human capillaries.

Nerve cells; branched

Shape of cells
??? are ??? to conduct impulses from one point to another.

WBCs; change

Shape of cells
Human ??? can ??? their shape to engulf the microorganisms that enter the body. 

compound light microscope (2000x) and electron microscope (50,0000x)

Microscopy
The detailed structure of a cell has been studied under two types of microscopes. what are these microscopes?

ultrastructure

Microscopy
The structure of a cell as seen under an electron microscope is called an?

Structure of the Cell

All activities inside the cell and interactions of the cell with its environment are possible due to these structures and how they are organized.