Transcript Taxonomy Viruses Bacteria Protists and Fungix

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Classification Key Terms
 Classification- grouping of objects or information
based on similarities
 Taxonomy- the science of classification
 Taxon (taxa- plural)- series of groups
Classification of Man
Largest
Kingdom – Animalia
Phylum – Chordata
Class Mammalia
Order Primate
Family Hominidae
Genus Homo
Species - sapien
Smallest
Pneumonic devices to remember the groups from largest to
smallest:
King Philip came over for good soup.
Ken put candy on Fred’s good suit.
Carl Linnaeus
 Carl Linnaeus developed the taxa. His system was based on
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physical and structural similarities of the organisms.
He also developed the naming system of binomial
nomenclature. It is a system that names each organism by a
genus and species.
Genius is capitalized and species is always lower case. Both
are either italicized or underlined. Example: Felis
domesticus
Sometimes organisms have been divided even further into
a subspecies or variety called trinomial nomenclature.
The more levels in common, the more related the species.
Dichotomous Keys
 A dichotomous key is an organized set of couplets of
characteristics to identify organisms.
 These keys will begin with general characteristics and lead
to couplets indicating progressively specific
characteristics.
 Always start with #1. If the organism falls into one
category, you go to the next indicated couplet.
 By following the key and making the correct choices, you
should be able to identify your specimen to the indicated
taxonomic level.
Viruses
Are Viruses Alive?
Parts of a Virus
Lytic Cycle Part 1
Lytic Cycle Part 2
Lysogenic Stage
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Viruses are NOT bacteria
Viruses cannot be treated with antibiotics because
they are not bacteria.
Examples of viruses: measles, mumps, chicken
pox, influenza, HIV/AIDS, HPV, mononucleosis,
and herpes.
Kingdom Monera
 The smallest and most common microorganisms are
prokaryotes —unicellular organisms that lack a
nucleus.
 All prokaryotes were once placed in the Kingdom
Monera.
 Biologists divided them into two different kingdoms:
the Eubacteria and the Archaebacteria.
 Most Monera organisms are autotrophic.
 Bacteria need a constant supply of energy, which is
released by the processes of cellular respiration or
fermentation or both.
Bacteria Reproduction
 Both archaebacteria and eubacteria have DNA in their cytoplasm
usually in a single loop shape.
 Binary fission is a type asexual reproduction where the bacteria
cell replicates its strand of DNA, doubles in size, and then
divides in half. (Identical cells, less genetic diversity)
 To increase genetic diversity, one bacteria may exchange genetic
material with another bacterium through pilli. This is a primitive
form of sexual reproduction.
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 When exposed to extreme conditions, bacteria will produce a
thick internal wall that encloses its DNA and some of its
cytoplasm in endospores. Endospores lie dormant to survive
extreme environments, then the bacterium will emerge again.
Archaebacteria
 Archaebacteria are sometimes referred to as ancient
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bacteria.
Archaebacteria live in extreme environments –
volcanic hot springs, low to no oxygen, heavy salty
waters, and acidic environments.
They have a cell wall, but it is not made of
peptidoglycan. Their cell membrane is mainly made of
lipids.
Most make their food by chemosynthesis.
Examples: methanogens and halophiles
Eubacteria
 Eubacteria are sometimes referred to as true or new bacteria.
 Eubacteria can live on land, in salt or fresh water, and in the
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human body.
Most have cells walls made of peptidoglycan (a mesh made of
carbohydrates and amino acids) outside of their membranes.
Most make their own food by photosynthesis or chemosynthesis.
Some are saprotrophs (breakdown decomposing organisms or
waste) and the rest are heterotrophs (parasitic)
There are three basic shapes: cocci (round), bacilli (bar-like),
and spirilla (spiral). They use one or more flagella to move.
Examples: Streptococcus (strep throat), Escherichia coli
Cell Walls of Eubacteria
Human Uses of Bacteria
 Foods and beverages
 Removal of wastes and poisons from water
 Mining minerals from the ground
 Synthesis of drugs and chemicals by genetic
engineering
 Production of vitamins in human intestines
 Nitrogen-fixing bacteria attach to roots of plants,
breakdown, and recycle inorganic materials
Protistia
Fungi-like
Fungi-like
Animal-like Protist:Protozoans
Animal-like Protist:Protozoans
Plant-like Protists
Plant-like Protist: Euglena
Common Animal-like Protists:
Paramecium Amoeba
Fungus-like Protists
Fungi
 Fungi are eukaryotic heterotrophs that have cell walls.
 Their cell walls contain chitin, a complex carbohydrate.
 Except for yeasts, all fungi are multicellular.
 Fungi are made up of thin filaments called hyphae. Each
hypha is only one cell thick.
 The bodies of multicellular fungi are composed of many
hyphae tangled together into a thick mass called a
mycelium.
 The mycelium permits a large surface area to come in
contact with the food source through which it grows.
Asexual Reproduction of Fungi
Asexual reproduction occurs when hyphae break off and
begin to grow on their own.
Some fungi produce spores, which scatter and grow. In
some fungi, spores are produced in structures called
sporangia.
Sporangia are at tips of specialized hyphae called
sporangiophores.
Sexual Reproduction of Fungi
Sexual reproduction involves two
mating types: “+” (plus) and “–”
(minus).
Hyphae of opposite mating types
meet and fuse, bringing “+” and
“–” nuclei together in one cell.
After growth and development, the
nuclei form a diploid zygote nucleus.
The zygote enters meiosis and
produces haploid spores.
These spores are capable of growing
into new organisms.
Classification of Fungi
Fungi are classified according to their structure and
method of reproduction.
The four main groups of fungi are:
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Common molds (Zygomycota) : molds that grow on meat,
cheese, and bread
Sac fungi (Ascomycota) yeasts
Club fungi (Basidiomycota) shelf fungi, puffballs, earthstars,
jelly fungi, and rusts
Imperfect fungi (Deuteromycota)
Sac Fungi
 Yeasts are unicellular fungi.
 Yeasts reproduce asexually by budding.
 Dry granules of yeast contain ascospores, which become active in a
moist environment.
Club Fungi
 The phylum Basidiomycota, or club fungi, gets its name
from a specialized reproductive structure that resembles a
club.
 The spore-bearing structure is called the basidium.
Imperfect Fungi
 Imperfect fungi, or Deuteromycota, are fungi that cannot
be placed in other phyla because researchers have never
been able to observe a sexual phase in their life cycles.
 Penicillium notatum is a mold that is the source of the
antibiotic penicillin.
Fungi Ecology
 Fungi rely on other organisms for energy.
 Many fungi are saprobes, which are organisms that obtain food
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from decaying organic matter.
Other fungi are parasites, which harm other organisms while living
directly on or within them.
Other fungi are symbionts that live in close and mutually beneficial
association with other species.
Fungi maintain equilibrium in nearly every ecosystem, where they
recycle nutrients by breaking down the bodies and wastes of other
organisms.
Parasitic fungi cause serious plant (corn smut and wheat rusts) and
animal diseases. A few fungi cause diseases in humans (athlete’s
foot, ringworm, thrush).
Lichen
 Lichens are mutualistic (both benefit) symbiotic
relationship between a fungus and a photosynthetic
organism.
 The photosynthetic organism is either a green alga or a
cyanobacterium, or both.
 The algae or cyanobacteria carry out photosynthesis,
providing the fungus with a source of energy.
 The fungus provides the algae or bacteria with water and
minerals and protects the green cells from intense sunlight.