3.1 Discovery of cells (Extension) 3.2 Microscope (Extension) 3.3 Basic structure of a cell 3.4 The similarities and differences between plant and animal cells 3.5 The cell as a basic unit of life Mind Map 3 The cell as the basic unit of life

3.1 Discovery of cells

Bark 1665 Robert Hooke Microscope 3.1 Discovery of cells Take a piece of cork

1665 Robert Hooke Microscope Take a piece of cork 3.1 Discovery of cells Bark

Microscope 1665 Robert Hooke Cork cells 3.1 Discovery of cells

In early 1800s, Schleiden, Schwann & Virchov suggested 3.1 Discovery of cells

The cell is the basic unit of structure and function in all living things Three rules of cell theory : Every cell originates from another preexisting cell 3.1 Discovery of cells All living things consist of cells

3.2 Microscope

light microscope dissection microscope electron microscope 3.2 Microscope

Eyepiece Magnification light microscope Objective 3.2 Microscope

Body tube Holds eyepiece & objectives light microscope 3.2 Microscope

can be rotated to bring the objective into line light microscope Revolving nosepiece 3.2 Microscope

Coarse adjustment light microscope to raise or lower the body tube for focusing 3.2 Microscope

supports the slide & allows the light to reach the specimen Stage light microscope 3.2 Microscope

holds the slide in position on the stage Clip light microscope 3.2 Microscope

reflects light from a light source Mirror light microscope 3.2 Microscope

regulates the amount of light passing through the condenser light microscope Iris diaphragm 3.2 Microscope

Arm Base light microscope 3.2 Microscope

arm coarse adjustment base eyepiece Summarylight microscope body tube revolving nosepiece objective stage iris diaphragm mirror 3.2 Microscope

A. Low Power Observation Experiment 3.1 Using a light microscope 3.2 Microscope

low power eyepiece Low power observation low power eyepiece into the top of the body tube 1. Insert the 3.2 Microscope

2. Adjust the mirror to reflect light through the hole in the stage mirror Low power observation 3.2 Microscope

3. Adjust the condenser & diaphragm to change the amount of light condenser & iris diaphragm Low power observation 3.2 Microscope

4. Select a low power objective Low power observation 3.2 Microscope

5. Place the slide onto the stage Low power observation 3.2 Microscope

6. While watching from the side, use the coarse adjustment to lower the objective until it is just above the slide Low power observation 3.2 Microscope

7. While looking through the eyepiece, carefully turn the coarse adjustment in the other direction until the object is in focus Low power observation 3.2 Microscope

B. High Power Observation 3.2 Microscope

1. Observe the specimen with low power first High power observation 3.2 Microscope 2. Move the slide so that the part to be observed is at the centre of view

3. Rotate the revolving nosepiece until 40X objective clicks into position High power observation 3.2 Microscope

4. Adjust the fine adjustment only until the object is in focus High power observation 3.2 Microscope

5. Adjust mirror, condenser & diaphragm to increase the light intensity High power observation 3.2 Microscope

biggerinverted What are the properties of microscopic images? 3.2 Microscope

= Magnification = Eyepiece magnification x objective magnification bigger 3.2 Microscope

Magnification = Eyepiece magnification Objective magnification 5 X 10 X 15 X 40 X 10 X 40 X 200 X 100 X 600 X Eyepiece magnification x objective magnification Magnification 3.2 Microscope

biggerinverted What are the properties of microscopic images? 3.2 Microscope

d Specimen p Image How ? inverted 3.2 Microscope

inverted d Specimen p Image d d d d d 3.2 Microscope

inverted d Specimen p Image d 180 o 3.2 Microscope

3.3 Basic structure of a cell

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

3.3 Basic structure of a cell is made up of Cellulose Cell wall

Feature HardProtect & support Large spaces between the cellulose fibers Allow large particles to penetrate the cell wall Cell wall Function 3.3 Basic structure of a cell

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

Protein & lipid consists of the movement of materials in or out of the cell Control 3.3 Basic structure of a cell Cell membrane

3.3 Basic structure of a cell Cell membrane is selectively permeable the movement of materials in or out of the cell Control

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

an aqueous solution of many substances e.g. protein consists of clear, jelly-like provides a medium for chemical reactions to take place 3.3 Basic structure of a cell Cytoplasm contains a lot of organelles & granules

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

3.3 Basic structure of a cell Chloroplast contains chlorophyll absorbs sunlight for photosynthesis

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

control activities of cell contains chromosomes made up of DNA 3.3 Basic structure of a cell Nucleus bounded by a nuclear membrane

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

Respiration takes place release energy 3.3 Basic structure of a cell Mitochondrion

Nucleus Chloroplast Mitochondrion Vacuole Cell wall Cell membrane Cytoplasm 3.3 Basic structure of a cell Plant cell

provides support when it is fully filled with water large, at the centre contains a solution of sugars, proteins and minerals 3.3 Basic structure of a cell Vacuole

contains crystals of insoluble waste starch granules 3.3 Basic structure of a cell Non-living granules

Difference ? Plant Cell Animal Cell no cell wall no chloroplast 3.3 Basic structure of a cell small vacuole

Cell membrane Nucleus 1.bounded by a nuclear membrane 2.contains chromosomes Plant Cells Cell wall (in plant cells only) Summary Animal Cells 3.3 Basic structure of a cell Cytoplasm 2. non-living granules e.g. starch (in plant cells only) 3. chloroplast (in plant cells only) 1.mitochondria e.g. glycogen (in animal cells only)

3.4 The similarities and differences between plant and animal cells

Shape Cell wall Chloroplasts Vacuole Nucleus Food reserves regularirregular peripheralcentre presentabsent large small or absent presentabsent starchglycogen 3.4 The similarities and differences between plant and animal cells

 a cell membrane surrounding the cytoplasm  a nucleus  mitochondria Both plant cells & animal cells contain 3.4 The similarities and differences between plant and animal cells

forceps fleshy scale leaf of onion bulb 1.Peel off a small piece of epidermis from the inside of a scale leaf of an onion. Experiment 3.2 Preparing temporary slides of the plant and animal tissues A. Onion epidermal cells 3.4 The similarities and differences between plant and animal cells

2.Cut it to a suitable size, about 5mm 2. Experiment 3.2 Preparing temporary slides of the plant and animal tissues A. Onion epidermal cells 3.4 The similarities and differences between plant and animal cells

3.Spread the tissue flat on a clean slide and add one drop of iodine solution on top of it. iodine solution epidermis Experiment 3.2 Preparing temporary slides of the plant and animal tissues A. Onion epidermal cells 3.4 The similarities and differences between plant and animal cells

4.Gently cover it with a cover slip and make sure no air bubbles are trapped in it. Then examine the slide under the low power of a microscope. cover slip Experiment 3.2 Preparing temporary slides of the plant and animal tissues A. Onion epidermal cells 3.4 The similarities and differences between plant and animal cells

ox eye slide 1.Gently touch the surface of an ox cornea with a clean slide. Experiment 3.2 Preparing temporary slides of the plant and animal tissues B. Ox corneal cells 3.4 The similarities and differences between plant and animal cells

methylene blue stain 2.Add a drop of methylene blue stain on the slide. Experiment 3.2 Preparing temporary slides of the plant and animal tissues B. Ox corneal cells 3.4 The similarities and differences between plant and animal cells

Experiment 3.2 Preparing temporary slides of the plant and animal tissues cover slip 3.Gently cover it with a cover slip. Then examine the slide under the low power of a microscope. B. Ox corneal cells 3.4 The similarities and differences between plant and animal cells

1.Put a drop of water on a clean slide. Experiment 3.2 Preparing temporary slides of the plant and animal tissues water slide C. Hydrilla leaf 3.4 The similarities and differences between plant and animal cells

Hydrilla 2.Put a piece of Hydrilla leaf into it. Gently cover it with a cover slip. Look at it under the low power of a microscope. Experiment 3.2 Preparing temporary slides of the plant and animal tissues C. Hydrilla leaf 3.4 The similarities and differences between plant and animal cells

1.Take a big flower with ripe stamens. Touch the anther with sellotape. Experiment 3.2 Preparing temporary slides of the plant and animal tissues D. Pollen grains anther pollen grains 3.4 The similarities and differences between plant and animal cells

slide 2.Stick the pollen grains onto a slide. Look at it under a microscope. Experiment 3.2 Preparing temporary slides of the plant and animal tissues D. Pollen grains sellotape 3.4 The similarities and differences between plant and animal cells

1.Put a transparent ruler on the stage of a microscope. Move the ruler into the centre of the field of view. Measure the diameter of the field of view. For example, in the diagram, the diameter is 3.5mm. Experiment 3.4 Measuring and comparing the size of plant and animal cells Method of measuring the size of the cells 3.4 The similarities and differences between plant and animal cells

2.Still using the microscope, observe a slide containing plant cells to be measured. Count the number of cells (end to end ) it takes to span the diameter of the field of view. In the diagram, 14 cells span the field of view. Therefore the average cell size is 3.5 ÷ 14 = 0.25mm. Experiment 3.4 Measuring and comparing the size of plant and animal cells Method of measuring the size of the cells 3.4 The similarities and differences between plant and animal cells

3.5 The cell as a basic unit of life

Nerve cell Epithelial cell Muscle cell3.5 The cell as a basic unit of life with different shapes

System level Organ level Tissue level Cells Three levels of organisation of cell 3.5 The cell as a basic unit of life

Epithelial cell Epithelial tissue Muscle cell Muscle tissue A tissue is a group of similar cells working together as a unit Tissue level Cells 3.5 The cell as a basic unit of life

Animal TissuePlant Tissue  muscular tissue  connective tissue  epithelial tissue  nervous tissue  mesophyll tissue  vascular tissue  epithelial tissue 3.5 The cell as a basic unit of life Tissue level Cells

Organ level Tissue level Cells 3.5 The cell as a basic unit of life

Muscular tissue Blood tissue Epithelial tissue Connective tissue Stomach 3.5 The cell as a basic unit of life Organ level Tissue level Cells An organ is composed of several different tissues group together to make a functional unit

organs in mammalsorgans in plants  heart  stomach  eyes  kidneys  lungs  leaves  stems  roots  flowers  fruits 3.5 The cell as a basic unit of life Organ level Tissue level Cells Examples of

System level Organ level Tissue level Cells Several organs and tissues working together to form a system. These organs and tissues are co-ordinated in the organisms. 3.5 The cell as a basic unit of life

Digestive system mouth oesophagus + stomach + small intestine + large intestine The cell as a basic unit of life

Mind Map consist of working together to form working together to form working together to form can be observed with contain contains function are used in which are Cells microscope control cells’ activities respiration non-living granules food or waste materials chloroplasts ( in plant cells only ) photosynthesis support the cells control of materials in and out of the cell support and prevent entry of excess water mitochondria Animal cellsPlant cells nucleus chromosomes cytoplasmvacuole cell sap cell membranecell wall tissues organs system