Cells: Structure and Function

Chapter 6

The People

• Jansen made the first microscope.• Anton van Leewenhoek discovered

microorganisms.• Hooke discovered cells.• Virchow and Schleiden developed the cell

theory.

First cells were Prokaryotes

Prokaryotes• No nucleus or orgnelles.• Nucleoid region is where DNA is located.• Ribosomes change genetic info. into proteins.• Flagella for movement• Cell wall, support and protection.• Plasma membrane control entry/exit.• Capsule protection, may cause disease.• Pili allow attachment to host.

Prokaryotic cells needed to do all life functions.

• Digest• Reproduce• Move• Remove wastes

• Single cells must do it all.

Eukaryotic cells

Eukaryotes

• Cells with oganelles doing specific tasks.• Appear long after first prokaryotes• Endosymbiotic theory.

– Mitochondria….chromosomes

Single cell

Cooperation

• Cells living together and gaining some survival advantage.

• Colonial Volvox

Volvox Colony

Volvox

• Many cells living as a single organismSize = protection

• Offspring protected within.• No specialized cells.

Reproduction

Creating multicellular organisms

Division of Labor

More Specialization

• Specialized cells for different tasks.• Do not do everything.• More Efficient• Cells specialize into Tissues, layers of cells.

Tissues

Levels of structure

• Tissues work together as organs

Organ

Levels of Structure

• Organs work together as Organ Systems• Each part more specialized. • More dependent on other cells.

Organ System

Levels of Structure

• Different Organ Systems work together in an Organism.

Organism

Levels of Structure

• Many members of a Species make a Population

Population

Levels of Structure

• Many different Species together make a Community

Community