Cell Structure


Cell Theory


Two types of cells




A digression:  What is this DNA stuff all about?

            Genes are made of DNA

            A chromosome is a strand of DNA many genes long


We inherit a complete set of DNA instructions from each parent

            Having two copies of each gene helps protect us from "copying errors"

                        A change in the instructions produces a mutation


Why are cells so small?

            There are two physical limits on cell size

1.      relationship between surface area and volume

2.      nucleus can only exert regulatory control over a limited area


Cell functions and cell organelles

            Control of activities

            Transport of materials in and out of cell

            Access to energy


Origin of eukaryotic cells

            Endosymbiont theory (Lynn Margolis)