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.