Presentation on theme: "Objectives -Define each of the following: Prokaryotes, eukaryotes,cell -Draw and label and -Draw and label Prokaryotes and eukaryotes -Mention the function."— Presentation transcript:
Objectives -Define each of the following: Prokaryotes, eukaryotes,cell -Draw and label and -Draw and label Prokaryotes and eukaryotes -Mention the function of the main organelles in the cell in the cell -Compare between -Compare between Prokaryotes and eukaryotes cell
1. Leeuwenhoek : - used a single powerful lens. - was the first person to see tiny living organisms in a drop of water. - Made detailed drawings of each kind of organisms. 2. Robert Hooke :- examined thin slices of cork. - found that it contains thousands of chambers called them cells. 3. Schleiden :- All plants are made of cells. 4. Schwann :- All animals are made of cells. 5. Virchow :- cells are produced from existing cells. Discovery of the cell
Cell theory states : 1.All living things are composed of cells. 2.Cells are the basic units of structure and function in living things. 3.New cells are formed by the division of pre-existing cells. 4.Cell contain genetic material which is passed on from parent to daughter cells Cells differ in their shape and size, but all cells share common structures. All cells have Cell membrane, Cytoplasm and Nucleus. Cell membrane : thin flexible barrier around the cell. Nucleus : Contains genetic materials and controls cell activity in most cells. Cytoplasm : material inside the cell membrane but not including the nucleus. Cell theory Basic cell structures
Cell structures Cell Wall Cell membrane NucleusOrganelles in the cytoplasm RibosomesLysosomesVacuolesChloroplasts Endoplasmic reticulumGolgi apparatusMitochondria
Eukaryotic Cells (yew KAYR ee yah tihk) cells with membrane- bound structures EX: animals, plants, fungi and protists
Cells divided into two categories : 1.Porkaryotic cells : do not have nucleus. 2.Eukaryotic cells : have nucleus. Prokaryotic cell Eukaryotic cell Smaller and simpler Larger and more complex Has cell membrane cytoplasm but no nucleus Has cell membrane cytoplasm and nucleus Does not have organelles Has organelles In bacteria All plants, animals, fungi, and many microorganisms Prokaryotes and eukaryotes
Nucleus -Nucleus was discovered by Robert Brown. -Nearly all eukaryotic cells contain nucleus. Function of the nucleus : 1.Control most of cell processes. 2.Contains The hereditary information ( DNA ) Components of the nucleus : - Chromatine : granular material spread out through the nucleus contain DNA and protein. When the cell divide chromatine condenses to form chromosomes 1.Nucleolus :small dense region where the assembly of ribosomes begin. 2.Nuclear envelope : double-membrane layer surround the nucleus. Contains many pores that allow materials to move in and out of the cell.
Cell Wall 1.Cell walls are found in plants, algae, fungi, and prokaryotes. 2.Cell wall lies outside of the cell membrane. 3.Cell wall allow substances to pass through it. 4.Cell wall made of : carbohydrate or protein fibers. Ex. Plant cell wall contains tough cellulose fibers. 1.Main function of the cell wall : provide support and protection to the cell.