O R G A N I Z A T I O N O F L I F E Cells Every living thing has at least one cell Some have only one and some have trillions Most cells are too tiny to be seen without a microscope ID: 670360
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Slide1
Cells:The Basic Units of LifeSlide2
O
R
G
A
NIZATION
O
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L
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ESlide3
Cells
Every living thing has at least one cell. Some have only one and some have trillions.
Most cells are too tiny to be seen without a microscope.
A chicken egg is one of the largest cells.
Not all cells look or act the same.You have 200 different kinds of cells: blood cells, bone cells, muscle cells …………Slide4
Tissues
A tissue is a group of cells working together to perform a specific job in the body. The material around and between the cells is also part of the tissue.
Examples of tissue: red blood cells, fat, and muscleSlide5
Organs
When two or more tissues work together to perform a specific job, the group of tissues is called an organ. Examples of organs: stomach, heart, intestines, liver, lung, and skin
Plants also have different kinds of tissues that work together. A leaf is a plant organ that contains tissue that traps light energy to make food.
Examples of plant organs: stem and rootsSlide6Slide7
The SkinThe skin is the body’s largest organ. An average-sized person’s skin has a mass of about 4.5 kg (almost 10 pounds!).Slide8
Brain FoodThe part of the skin, hair, and nails that we can see is DEAD tissue. Isn’t it strange that we put so much effort into making sure our dead cells look nice?Slide9
Organ Systems
Organs work together in groups to perform particular jobs. These groups are called organ systems.
Each system has a specific job to do in the body.
Examples:
digestive system breaks down food to use by your body’s cellsnervous system transmits information back in forth between the brain and other parts of the bodySlide10
There are 11 main organ systems.
The organs in the organ system depend on each other. If any part of the system fails, the whole system is affected. And failure of one organ system can affect other organ systems.
Main organ systems : integumentary system, skeletal system, muscular system, nervous system, endocrine system, cardiovascular system, lymphatic system, respiratory system, digestive system, urinary system, reproductive systemSlide11
Organism: Independent Living
Anything that can live on its own is called an organism.
All organisms are made up of at least one cell.
organisms made up of one cell –
unicellularorganisms made up of groups of cells – multicellularSlide12
The Big Picture
Although unicellular and multicellular organisms can live on their own, they usually do not live alone. Organisms interact with each other on many different ways.
Populations
– groups of organisms that are of the same kind and that live in the same area
Example – all the white tail deer in the forestCommunities - two or more different populations living in the same areaAll the populations combined in the forest (deer, rabbits, snakes, etc..)Ecosystems – all the communities and all the nonliving things that affect it, such as water, soil, rocks, temperature, and lightEcosystems on land – terrestrial ecosystemsEcosystems in water – aquatic ecosystemsSlide13Slide14
Discovery of CellsSlide15
Seeing the first cells
1665 - Robert Hooke –
B
ritish scientist – used cork (soft plant tissue found in the bark of a tree) – He saw tiny boxes and called them cells.Slide16
Early discoveries
1673 – Anton van Leeuwenhoek
– Dutch merchant – used a handmade microscope to look at pond scum – He saw many small creatures. He also looked at blood from animals and teeth scrapings.
First
to see bacteria and discovered that yeast is a unicellular organism.Slide17
The Cell Theory
Matthias Schleiden
– 1838 – all plant parts are made of cells
Theodore Swann – 1839 - wrote the first part of the cell theory.
All organisms are composed of one or more cells.The cell is the basic unit of life in all living things.1858 – Rudolf Virchow – wrote the third part of the cell theoryAll cells come from existing cellsSlide18
All cells have: Cell membrane-
surrounds all cells; acts as a barrier between the inside of the cell and its environment; controls what comes in and what goes outHereditary material
–
cells receive a copy of hereditary material (DNA) It controls all of the activities of the cell and contains the information needed for that cell to make new cells
Organelles – structures within a cell that allow it to live, grow, and reproduceCytoplasm – fluid that surrounds the organelles within a cellSmall size – almost all cells are too small to see with the naked eyeSlide19
Amoebas
An amoeba is a single celled (unicellular) organism. It cannot get large enough to be seen. As a cell gets larger, it needs more food and produces more waste. Therefore more material must be able to move in and out through the cell membrane.
To keep up with these demands, a growing cell needs a larger surface area through which to exchange materials. As the cell’s volume increases, its outer surface grows too.
Go to page 12 to help explain!!!
Surface-to-Volume RatioSlide20
Benefits of being Multicellular
A single cell as big as you would have an incredibly small surface-to-volume ratio and would not survive because its outer surface would be too small to allow in the materials needed. Multicellular organisms grow by producing MORE cells, not LARGER cells
.
An elephant has more cells than you, not larger cells.Slide21
Many kinds of cellsHaving many different cells that are specialized for specific jobs allows multicellular organisms to perform more functions than unicellular organisms.
Different kinds of cells can form tissues and organs with different functions.
Some specialized cells: muscle cells, eye cells, brain cells….
Be glad you are not UNICELLULAR! How boring!Slide22
Two types of cells
Prokaryotic Cells
Also called bacteria
World’s smallest cells
No nucleusCircular DNA (shaped like a rubber band)No membrane-covered organellesEukaryotic CellsMore complexAll other cellsHave a nucleusHave membrane-covered organellesLinear DNA stored in the nucleusSlide23
Eukaryotic CellsAnimal Cells
Nucleus
Ribosomes
Cell Membrane
Endoplasmic ReticulumLysosomesMitochondriaGolgi ComplexPlant CellsNucleusRibosomesCell MembraneEndoplasmic ReticulumLysosomesMitochondria
Golgi Complex
Cell Wall
Large Vacuole
ChloroplastSlide24
The Cell's Command Center -- The Nucleus
Largest and most visible organelle in a
eukaryotic
cell
Surrounded by a nuclear membrane for protectionStores DNA that has information on how to make all the cell’s proteins (almost all chemical reactions important to the cell’s life involve protein)Read more: List of Organelles | eHow.com http://www.ehow.com/info_8642034_list-organelles.html#ixzz23M2NtNGkSlide25
The Energy Plant -- Mitochondria
ATP
(molecule that supplies energy to fuel the cell’s activities) made here from food molecules
Bean shaped – surrounded by two membranes
Must have oxygenHighly active cells (such as heart and liver) have thousandPowerhouse of the cellSlide26
Protein Factory -- Ribosomes
Make protein chains out of
amino acids
Smallest but MOST abundant organelle
Not covered with a membraneALL cells have ribosomes (prokaryotes included)Slide27
The Cell’s Delivery System – Endoplasmic Reticulum
Membrane-covered compartment that
makes
lipids and other materials for use inside and outside the cellBreaks down drugs and other damaging chemicals Internal delivery system Looks like flattened sacks stacked side by sideSlide28
Shipping– Golgi Complex
Packaging -Vesicles
Looks like the ER but is located closer to the cell membrane
Modifies lipids and proteins from the ER and delivers them to other parts of the cell or outside the cell
Vesicles are pieces of the Golgi complex that pinches off and stores the final products Slide29
Trash Collector -- LysosomesSpecialized vesicles in animal cells
Contain enzymesDestroy worn-out or damaged organellesGet rid of waste materials and protect the cell from foreign invaders
If the membrane of a lysosome opens, the enzymes will spill out into the cell and kill the cell. (How a tadpole loses its tail)Slide30
Plant Cells -- Chloroplasts
Only found in plants and algae
Energy-converter
Has two membranes and structures like stacked coins and contains
chlorophyll – which makes the chloroplast greenChlorophyll traps the energy from sunlight and uses it to make sugar in the process photosynthesis.Mitochondria then use the sugar to make ATP.Slide31
Cell Wall
Found in plant cells Outside the cell membrane
Made of cellulose (sugar)
Provides strength and support to cell membraneSlide32
Water cooler- Vacuoles
Most plant cells have very
large
vacuoles.Membrane-coveredStores water and other liquidsWhen full, helps support the cellWhen empty, the cell shrivels (causing the plant to wilt)Slide33
Homeostasis
(1) The tendency of an
organism
or a
cell to regulate its internal conditions, so as to stabilize health and functioning, regardless of the outside changing conditions (2) The ability of the body or a cell to seek and maintain a condition of equilibrium or stability within its
internal
environment
when dealing with
external
changes
In humans, homeostasis happens when the
body
regulates body
temperature
in an effort to maintain an
internal
temperature
around 98.6 degrees Fahrenheit.
For example
, we
sweat
to cool off during the hot summer days, and we shiver to produce
heat
during the cold winter
season
. Slide34
Connective Tissue
Joins, supports, cushions and insulatesExamples: blood, bone, cartilage, ligaments, tendons,Slide35
Epithelial Tissue
Epithelial tissues consist of continuous sheets of cells that provide a protective covering over the whole bodyThey also form the lining membranes of internal organs, cavities, and passageways and cover internal organsSlide36
Muscle Tissue
Contracts or shortens to cause movementSlide37
Nerve Tissue
Carries message to and from the brainAllows us to see, hear, feel…….
Makes up brain, spinal cord and nerves