Cell PEOPLE, Cell Size, and Cell Specialization Chap 7-1 & t

Microscope/Leeuwenhoek image: Animation from: ___________________________________ a Dutch microscope maker was the first to see LIVING ORGANISMS. Anton van Leeuwenhoek

Microscope image: Cork image: Hooke image: Robert Hooke used a microscope to examine a thin slice of cork and saw “little boxes” He called them “CELLS” because they looked like the small rooms that monks lived in called Cells

Robert Brown Discovered the nucleus around 1833 Known as the Brown Nucleus Also credited with naming cytoplasm

Plant image: Schleiden image: German botanist __________________________ concluded that ALL PLANTS are made of cells Matthias Schleiden

Schwann image: Animals image: German zoologist _________________________ concluded that ALL ANIMALS ARE MADE OF CELLS Theodor Schwann

Virchow: Mitosis: German medical doctor _____________________ saw dividing cells in the microscope and reasoned that cells come from other cells Rudolph Virchow

Janet Plowe Cell membrane is an actual physical structure, and not just an interface between two liquids.

CELL THEORY 1. All living things are ________________________. 2. Cells are the basic unit of ____________ & _____________ in an organism. (cell = basic unit of _____________) 3. Cells come from the reproduction of ____________ cells Cell image: MADE OF CELLS existing life STRUCTURE FUNCTION

American Biologist _____________________ provides evidence for the idea that certain organelles within cells were once free-living cells themselves. = _________________________ Lynn Margulis ENDOSYMBIOTIC THEORY

See a movie about ENDOSYMBIOTIC THEORY

Evidence for Endosymbiotic theory 1.Mitochondia and chloroplasts have circular_______ similar to bacteria. 2. Mitochondria and chloroplasts have ______________ whose size and structure resemble bacterial ribosomes. 3. Mitochondria and chloroplasts replicated using _________________ like bacteria. 4. _______________________ of mitochondria and chloroplasts have a composition similar to bacterial membranes. DNA Binary fission RIBOSOMES INNER MEMBRANES

All living things made of cells BUT… organisms can be very different. UNICELLULAR MULTICELLULAR Image from:

CELL SIZE Typical cells range from: 5 – 50 micrometers (microns) in diameter

How big is a micron ( µ ) ? 1 cm = 10,000 microns 1” = 25,000 microns

MULTICELLULAR ORGANISM don’t just contain MANY CELLS. Image from: They have different kinds of cells doing different jobs

Cells in a multi-cellular organism become SPECIALIZED by turning different genes on and off Image from: Cell Specialization =DIFFERENTIATION

SPECIALIZED ANIMAL CELLS Muscle cells Red blood cells Cheek cells

Specialized Plant cells Guard cells Xylem cells Pollen Guard cells: Xylem: Pollen:

Powerpoint adapted from Brookings High School South Dakota