The Characteristics of Life Without them…you’re nothing but dirt. Well okay…maybe not even that. Perhaps you’re really just a bunch of cheap chemicals …..Who knows...

The Characteristics of Life §There are basically 6 things that Scientist define as required for life. l 1) Living things are organized. All living things are made of cells –The basic unit of structure and function in an organism May be Unicellular - Single celled organism. May be Multicellular - Organism composed of many cells.

The Characteristics of Life l 2) Living things must acquire and use energy. Ya got’ta eat, or at least soak in the sun. l 3) Living things respond to stimuli. Plants bend toward light. Worms recoil from touch. Dogs bark when startled. You feel unbridled horror at the sight of a science test.

The Characteristics of Life l 4) Living things reproduce. What good is it if you can’t make more?…. l 5) Living things grow and develop and adapt. Nothing starts out and adult. Nothing is what it has always been. –Darwin l 6) Maintain internal conditions separated from an outside environment. Homeostasis. Kind of loops back to the first point.

And now! For something completely different

The Cell Theory §The Modern Cell Theory consists of three statements based on a large body of scientific research. l All living things are composed of cells. l All cells come from pre-existing cells. l The cell is the fundamental unit of structure and function in living things.

The Cell Theory §The Modern Cell Theory is derived from the work done by Hooke, Leeuwenhoek, Schleiden, Schwan, Virchow and a few others l Who are these people?

If you really want to know these people…. §I’ve written 5 new DAR’s for these scientist. l Hooke, Leeuwenhoek, Schleiden, Schwan, Virchow §Go ahead….make my day. §But anyway………………….

The Cell Theory l What then new found technology catapulted these scientist into the stratosphere of leading edge science? –CD

The Microscope!

The Microscope §A microscope makes small objects look larger §A compound microscope has more than one lens

The Microscope!

The Microscope! §Important Parts. l Objective lens - gathers light from the specimen l Eyepiece (ocular lens)- transmits and magnifies the image from the objective lens to your eye l Coarse-focus knob - used to bring the object into the focal plane of the objective lens l Fine-focus knob - used to make fine adjustments to focus the image

The Microscope! §Determining Total Magnification: §Locate the numbers on the eyepiece and the low power objective §Eyepiece magnification x Objective magnification =Total Magnification §For high power objective. §Eyepiece magnification x Objective magnification =Total Magnification

The Microscope!

The Microscope §A bit of history l Robert Hooke in 1663 using a microscope he built himself was one of the first people to observe cells. He called them cells because they reminded him of tiny rooms. l Anton van Leeuwenhoek who at about the same time built his own microscope and was the first to observe “animalcules” meaning “little animals.” in pond water.

The Microscope 1590 First compound microscope 1660 Hooke’s compound microscope 1683 Leeuwenhoek’s microscope 266x 1886 Modern compound light microscope 1000x 1933 Transmission Electron microscope 500,000x 1965 Scanning Electron microscope 150,000x in 3D 1981 Scanning Tunneling microscope 1,000,000x