Learning Objectives Dear Students, The learning objectives below ...
Objectives
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ObjectivesObjectives
-Define each of the following:-Define each of the following:
Prokaryotes , eukaryotes ,cell
-Draw and label -Draw and label Prokaryotes and and eukaryotes
-Mention the function of the main organelles -Mention the function of the main organelles
in the cellin 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 Nucleus Organelles in the cytoplasm
Ribosomes Lysosomes Vacuoles Chloroplasts
Endoplasmic reticulum Golgi apparatus Mitochondria
Eukaryotic CellsEukaryotic Cells(yew KAYR ee yah tihk) (yew KAYR ee yah tihk)
cells cells withwith membrane- membrane-bound structuresbound structures
EX: EX: animalsanimals, , plantsplants, , fungifungi and and protistsprotists
Cells divided into two categories :
1. Porkaryotic cells : do not have nucleus.
2. Eukaryotic cells : have nucleus.
Prokaryotic cellProkaryotic cell Eukaryotic cellEukaryotic cell
Smaller and simplerSmaller and simpler Larger and more complexLarger and more complex
Has cell membrane cytoplasm Has cell membrane cytoplasm but no nucleusbut no nucleus
Has cell membrane cytoplasm Has cell membrane cytoplasm and nucleusand nucleus
Does not have organellesDoes not have organelles Has organellesHas organelles
In bacteriaIn bacteria All plants, animals, fungi, and All plants, animals, fungi, and many microorganismsmany 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.
protectsprotects the cell the cell
gives gives shapeshape
is made of is made of cellulosecellulose
A cell wall is found in A cell wall is found in plantsplants, , algaealgae, , fungifungi, , & most & most bacteriabacteria..
CELL WALLCELL WALL
CYtoskeleton
Cell Wall