Bacteria, Protists, and Fungi
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Transcript Bacteria, Protists, and Fungi
Bacteria, Protists, and
Fungi
7th
Bacteria are very small unicellular organisms that do not contain
organelles
This makes them prokaryotes
They have DNA, but it floats around the cell as a nucleoid
How do they get food?
Producers- anything that can make food
Some use the sun and photosynthesis
Others use different chemicals like sulfur to make food
Consumers- any organism that breaks down or relies on another living
thing
Some bacteria are decomposers
Others help break down food in your large intestine
Other make you sick like strep throat
Do bacteria breath?
Some need oxygen to survive- they are call aerobic
Other can survive without oxygen- they are called anaerobic
Both are forms of respiration which is the break down of sugar
into energy for the cell
Bacteria come in 3 main shapes all of which are very small compared to eukaryotes like plant and
animal cells
Cocci- sphere
Spirilla- spiral
Bacilli- rod
2 types of bacteria
Archaebacteria- live in harsh environments
Also called-extremophiles
Deep sea vents and sulfur ponds
Eubacteria- live everywhere else
they are larger in size compared to archaebacteria
Some bacteria are needed to survive
They live in your intestine and help break down nutrients
They can make antibiotics
Other are bad
They are called a pathogen- any organism that causes a disease
Tooth decay, strep throat, acne
are examples of hurtful bacteria
Vaccines and pasteurization
2 helpful technologies that help get rid of bad bacteria
Vaccines produce antibodies that help fight off bad bacteria
Like for tetanus and whooping cough
Pasteurization is used to kill bacteria with heat, but not harm the
flavor of food
It extends the lifetime a food is good for, without it, milk would only last a
few days
Like milk and yogurt
Bacteria are found in all sorts of places
Helping decompose trash
Help get rid of sewage
Help make cheese and other foods
Help break down oil
They make life sustaining molecules
Nitrogen fixing bacteria are the only living organisms that can take
nitrogen gas from the air, and turn it into useful molecules to make
proteins and DNA.
Without bacteria, we would not be alive
We find these bacteria on many legume roots
Beans, peas, soy
Protist
Eukaryote organisms that are single or multicellular
They live in wet and moist environments
They would dry out if they were on land because they don’t
have anyway of keeping water
Come in 3 types
Fungal like
Animal like
Plant like
Fungal like protists
Include organisms called:
Slime molds
Downy mildews
Water molds
They are all consumers and some are parasitic and will
kill an organism
Live most of life as a single cell, then join together for
reproduction
Slime mold
Downy Mildew
Water mold- caused potato
famine in Ireland
Animal like protist
Protozoan- a one celled organism that lives in water and
is a consumer or parasite
Some contain flagella other have cilia- this is how they are
organized into groups
Paramecium
Amoeba- move by pseudopodsfalse foot
Malaria is caused by a protozoan called Plasmodium
volvox
It is spread by mosquitos
Use nets to protect self
Kills more than 1,000,000 people a year
Giardia- is a flagellated protozoan that causes gastro
intestinal problems
Get it from drinking bad water
Plant like protist- these are
Algae's
Can be either single celled or multicellular
Single celled include:
Diatoms, Spirogyra, Volvox, and Euglena
Multicellular algae include
Green, red, and brown algae
These are the organisms that we see on the beech
They can make huge underwater forests of algae
They produce a majority of the oxygen in the world
Think about how large the ocean is and all the algae that lives in it
Green algae
Red algae-
Brown algae- Kelp
Fungi
Most fungi are multicellular eukaryotes
Some like yeast are single celled eukaryotes
All fungi are consumers with a cellwall
Some are saprophytes meaning they decompose and break
down organisms for energy
Others are parasitic like athletes foot or ringworm which is
caused by a fungal infection
Reproduction of fungi
They use spores to spread from place to place
Each spore contain the material needed to start a
new fungus
They can reproduce by either sexual or asexual
reproduction
asexual means that more spores are made and
released
Sexual means that 2 different fungi join together
Structure
We actually see very little of a fungus
The majority of the body of the fungus is buried this
is called the hyphae
When 2 hyphae join together sexual reproduction
occurs and genetic material is combined
The hyphae also does the majority of the
decomposing
They release enzymes which break down the material
and then the fungi absorbs the nutrients
Types of Fungi
Use the reproductive structures to determine type along
with other features
3 major types of fungi
Club fungi
Get funky!!
They also include mushrooms, puffballs, and
toadstools
In these organisms, spores are produced on gills on
the underside of the mushroom cap.
Sac Fungi
Molds, morels, and truffles
Spores are produced in small sacs in the reproductive
structure
Yeast- single celled fungi
Used to make bread
As it breaks down sugars it releases CO2 causing bubbles in the
bread
Naturally occur in the body, but too much can cause sores
Zygospore fungi
Cause bread to go bad
The hyphae fuse together and form a reproductive structure
called a sporangia
This then makes spores that are released.
Pros about fungi
Decompose dead organisms returning good nutrients to
soil
Help plants get nutrients- form a mycorrhizae
This is a symbiotic relationship between plant roots and
fungi, where the fungi gets food and the plant gets
nutrients
Penicillin and other medicines can be made from fungi
Break down cell wall of bacteria
Help us make food like bread and cheese
Cons for fungi
Cause health issues if bad ones are ingested
Live on skin
Cause huge amounts of crops to be destroyed
Spoil food
Lichens
Cool little relationship between bacteria and fungi
Fungi break down nutrients
Cyanobacteria uses photosynthesis to make food
Both benefit
They are the first to live on newly formed rock that will
help make soil for new bigger organisms.