2. Cytology The study of cells. Living Environment Created by Randecker & Offenbacher On 9/04 & 9/05

3. All living things are composed of cells. Prokaryote – a cell without organelles Eukaryote – cell with defined organelles Unicellular - composed of one cell Multicellular - composed of more than one cell.

4. Prokaryote Eukaryote

6. Founding Fathers of Cytology Leeuwenhoek- (1600’s) made the first simple microscope. Magnifying glass. First to see bacteria, protozoa.

8. Hooke- 1655 made compound microscope with two lenses. First to see “cell” in slices of cork.

10. Brown- 1831 concluded that all plant cells contain a nucleus.

11. Schleiden 1838- German botanist who concluded that “all plants are made of cells”. Schwann 1839- German zoologist who concluded that “all animal s are made of cells”. Virchow 1855 concluded that “all cells arise from preexisting cells”.

12. THE CELL THEORY 1. All living things are made of cells. (basic structure). 2. All cells carry out life functions. (basic function) 3. All cells come from pre-existing cells.

13. EXCEPTIONS to the CELL THEORY 1.Where did the first cell come from? 2. VIRUSES? Can reproduce inside a host but outside it shows no sign of life. 3. Mitochondria and chloroplasts contain genetic material and can reproduce.

14. Levels of organization Cell- basic unit of life. Tissue- group of cells performing the same function. Lung tissue Organs- group of tissues performing the same function. Lung, heart Organ system- group of organs that perform the same function.ex. Respiratory system Organism- group of organ systems working together.

15. Parts of a Cell Ribosome- synthesis proteins Nucleus- controls cell activity Cell membrane- regulates what enters and leaves the cell Mitochondria- carries out cellular respiration to release energy. Endoplasmic reticulum- system of channels that transport materials.

16. Smooth ER- without ribosome Rough ER- with embedded ribosome. Lysosomes- digestive enzymes to break down substances. Nucleolus – synthesize ribosome. Cytoplasm- liquid portion of the cell Vacuoles – storage bins of the cell.

19. Differences between plant and animal cell Plant- Cell wall No centrioles 1 Large vacuole (Tonoplast) Chloroplast (chlorophyll) Animal- No cell wall Centrioles present Many small vacuoles No chloroplasts

20. Plant parts Cell wall- rigid, made of cellulose and gives support and structure. Chloroplasts- contain chlorophyll, photosynthetic organ Tonoplast- large vacuole that gives plant support.

21. Smallest cell in the body Granule Cell of the Cerebellum 4um Human sperm cell is 25um (with tail)

22. Smallest cell in the world Prasinophyte algae.8um

23. Largest cell in the body Anterior Horn Cell in the spine 135um Human egg is 120um

24. Largest cell in the world The egg from an ostrich 15cm

25. How many cells are in the Human Body Approximately 65 trillion cells make up the adult human body