Monerans
Oldest Life on
Earth
Mr. Kempfer
7th Grade Science
Monerans
Single celled
 No nucleus
 Most commonly known as
Bacteria
 Appeared 3.5 billion years ago
 Most numerous organism
– 2.5 billion bacteria in a gram
of soil
 How are bacteria different from
other cells?

Types of Bacteria

Shapes of bacteria
– Coiled, ball, rod,
candy-apple, blobs

Can be any color
– Red, yellow, blue,
purple

Found in water, air,
soil and other
organisms
Amazing Bacteria
Some bacteria live in
volcanoes, boiling water,
glaciers, acid pools and at
very high pH’s
 Bacteria are simple but
still perform all of the
functions necessary for
life.
 How would this be an
advantage on early Earth?

Structure of Bacteria
 Have
a cell wall
– Protects and gives shape
 Cell Membrane
– Lets stuff in and out
 Cytoplasm
 No nucleus
– Genetic material just
floats in the cytoplasm
 What parts do bacteria
share with other cells?
Movement of Bacteria
 Most
bacteria can’t move
on their own.
– Moves by air, water or
hitches a ride
 Some have flagellum
– Whip like tails that
propel them through a
liquid.
 Why do bacteria need to
move?
Life Functions of Bacteria
 Some
need oxygen,
some don’t
 Most are heterotrophs
 Some are parasites
 Some are decomposers
 Some are autotrophs
 Some eat sulfur and iron
 Why do you think
bacteria are so diverse?
Reproduction
Bacteria reproduce by
splitting into 2
 Can double their numbers
in 20 minutes
 In 24 hours could weigh 2
million kilograms!!!

In
5 days would
weigh more than
the Earth!!!
?What keeps
this from
happening?
Bacteria in Control
Reproduction depends on
food supply.
 When there’s no food,
bacteria form an endospore.
 This is like a suit of armor
against the environment
 Bacteria can survive
bleach, boiling, freezing
and radiation in an
endospore
 When would a bacteria
need an endospore?

Bacteria in Nature
 Bacteria
are an essential
part of the food and
energy relationships that
link all life on Earth.
 Decomposers,
Producers, food for
consumers
 Oxygen producers
– Why is this important?
Pioneers
Bacteria are the first to move
into a new area and populate
it.
– Volcanic areas
– Forest fires
 Symbiotic Relationships
– Help us digest food
– Give plants nitrogen
 How does this help an
ecosystem?

Bacteria and Humans
 Bacteria
are used in the
production of food, fuel,
medicines and other
products.
 Some, though, can spoil
food, cause diseases and
poison water.
 Name a bad bacteria.
Bacteria and Food
Used to make cheese, yogurt,
pickles, sour cream, soy
sauce, vinegar, high-fructose
corn syrup (sugars)
 Blue-green algae are 70%
protein…yum!
 We heat food to kill bad
bacteria
 What can bad bacteria do to
food?

Bacteria as Fuel
 Certain
bacteria can break
down fruit rinds, dead
plants, manure and
sewage to make methane
gas (natural gas)
 Dead bacteria and other
stuff became crude oil in
time
Medicine
 Bacteria
is used to make
anitbiotics
– Chemicals that poison
other bad bacteria
 Bacteria can cause …
– Strep throat,
pneumonia, tetanus
and Lyme disease.
 Can antibiotics fight a
virus?
Bacteria and Industry
 Used
to tan leather
 Extract copper, silver
and gold from rock
 Coloring food,
cosmetics, removing
stains and changing
chemicals.
 Damages asphalt, water
and gas pipes and oil
drilling machinery.
Up Next…
Protists