Download Chapter 10 – The cell is the basic unit of life. Using a Microscope

Chapter 10 – The cell is the basic unit of life.
Using a Microscope
- Worksheet (diagram and functions of a microscope)
- Lab (p. 394-395)
What you are viewing under a microscope (P.393)
- Magnified image (larger)
- Inverted image (upside down)
- Reversed image (backwards)
What are living things made of?
Early idea: all living things are made of air, fire and water
Now: all living things are made of cells (cell theory)
Cell: the basic, functional unit of life
Characteristics of Living Things/Cells (P. 391 Table 10.1)
All living things...
1.Grow
2.Move
3.Respond to stimuli
4.Reproduce
Growth
•A result of the cells in your body increasing in number
•New cells will grow to replace old cells that die.
Movement
•A change in position, shape or location (locomotion)
Respond to Stimuli
•Stimulus: anything that causes an organism to react.
•Maybe external or internal
Reproduction
•Producing more of the same kind (offspring)
Examples
Parts of a Compound Light Microscope
Part
Function
Eyepiece
Barrel (Tube)
Arm
Coarse Adjustment Knob
Fine Adjustment Knob
Objective Lenses
Used for viewing and contains a lens that magnifies
Holds the eyepiece and objective lenses at proper distance from each other
Supports the eyepiece and used for carrying
Brings an object into focus at low or medium power
Brings an object into focus at high power
Magnify the image (3 or 4 lenses)
Revolving Nosepiece
Stage (May have clips)
Holds the three objective lenses
Supports the slide
Iris Diaphragm
Light Source/Lamp
Base
Controls the amount of light reaching the specimen
Supplies the light needed to view the slide
Supports the entire microscope
The Cell Theory states:
•The cell is the basic unit of life.
•All living things are made of one or more cells.
•All cells come from other living cells.
Seven Cell Organelles...
Cell membrane:
•Found in both plant and animal cells
•Surrounds and protects the contents of the cell
•Controls the movement of materials in and out of the cell
Cell wall:
•Found only in plant cells
•Tough, rigid structure that give plant cells their box-like shape
•Made mostly of cellulose
Chloroplast:
•Green structures that contain chlorophyll
•Capture the sun’s energy for photosynthesis
•Found only in plant cells
Cytoplasm:
•Found in both plant and animal cells
•Jell-like fluid that in which the organelles float
•Helps to move materials like food to different parts of the cell
Nucleus:
•Found in both plant and animal cells
•Large round structure often visible
•Contains the chromosomes
•The “control centre” of the cell
Vacuole:
•Balloon-like spaces in the cytoplasm
•Stores materials that cannot be used right away
•Found in both plant and animal cells (smaller and more numerous in animal cells)
Mitochondrion: (plural: Mitochondria)
•Oval, bean-like structures
•Produces energy by breaking down food particles
•Found in both plant and animal cells
Plant vs. Animal Cells
Vacuole
Cytoplasm
PLANT CELL
Organelle
Cell Wall
Cell Membrane
Chloroplast
Cytoplasm
Nucleus
Vacuole
Mitochondria
ANIMAL CELL
Plant Cell
√
√ Brick Shape
√
√
√
√ large and less
√
Animal Cell
√ Round Shape
√
√
√ small and more
√
What are three main differences between plant and animal cells?
1. Plant cells have chloroplasts
2. Plant cells have cell walls which give them a rectangular, regular shape
3. Plant cells have fewer and larger vacuoles
Dividing Cells
•Necessary for growth and reproduction
•Will replace cells that are dead or in need of repair
•How does this happen?
Mitosis
Growth and Reproduction depend on cell division
Mitosis is the process by which cells divide to produce more identical cells.
-Example of cell division for growth: skin cells divide to produce more skin cells
to heal a cut or injury.
-Example of cell division for reproduction: a bacteria cell divides to become
two cells
Mitosis occurs in body cells and Meiosis occurs in sex cells (egg and sperm)
Videos
http://www.sci.sdsu.edu/multimedia/mitosis/mitosis.gif
http://www.youtube.com/watch?v=m73i1Zk8EA0
http://www.youtube.com/watch?v=ZEwddr9ho-4
Energy for Cells
•Cells need energy for all life processes.
•Energy is stored in food called glucose (a type of sugar)
•To release energy, cells must carry out cellular respiration, the energy is converted to
another form of energy.
•Takes place in the mitochondrion.
•Most energy is released as heat.
•Oxygen is necessary for cellular respiration.
•Carbon dioxide and water vapour are waste gases produced. These are removed
from the cell.