Transcript Unit 9 Classification and Microorganisms

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Cell type: prokaryotic
Cell structure: Cell walls with peptidoglycan
Number of cells: UNIcellular
Nutrition: heterotrophic or autotrophic
Examples: Streptococcus P., E. Coli
Cell type: prokaryotes
Cell Structures: cell walls
without peptidoglycan
 Number of cells:
UNIcellular
 Nutrition: mostly
chemoautotrophic
 Examples: Methanogens;
Halophiles
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Cell type: eukaryotes
Cell structure: plant like, animal like, or
fungus like
Number: most unicellular; some colonial
(work together in a colony)
Nutrition: heterotrophic (animal and fungi
like) or autotrophic (plant like)
Examples: amoeba, paramecium, slime
molds, algae
Cell type: eukaryotes
Cell structures: cell walls
made of chitin
 Number: mostly
multicellular (yeasts
unicellular)
 Nutrition: Absorptive
heterotrophs
 Examples: mushrooms,
morels, yeasts
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Cell type: eukaryotic
Cell structures: Cell wall of cellulose;
chloroplasts; large vacuole
Number: multicellular
Nutrition: Photoautotrophic
Examples: mosses, ferns, evergreens, flowers
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Cell type: eukaryotic
Cell structures: no cell walls; centrioles
Number: multicellular
Nutrition: heterotrophic
Examples: invertebrates; fish; amphibians;
reptiles; birds; mammals
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Unicellular – organisms that consist of only a
single cell ( uni- means one)
Multicellular – organism that contain
hundreds, thousands, or even trillions of cells
(multi – means many)
Colonial – organisms that work
and live together in a colony.
 Example: Volvox
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*Colonial organisms are different from
multicellular because individual cells will still
live if they are separated from the colony.
*Colonial organisms were probably the 1st step
towards multicellular organisms via natural
selection
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Taxonomy – the study of classifying
organisms and assigning organisms a
universally accepted name.
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the Greek philosopher (384-322 BC)
developed the first system for classifying
organisms.
He divided organisms into 2 groups: Plants
and Animals
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(1707-1778) a Swedish botanist, whose
classification was based on the physical and
structural appearances of organisms.
He developed Binomial Nomenclature
a two word naming system that uses the
Genus and the Species as the scientific name.
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Scientific names are usually in Latin or Greek
(because it was the common language)
Scientific names are italicized or underlined
The Genus is always capitalized, the species is
lowercased
Ex: Homo sapiens, Lynx rufus (bobcat)
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There are 8 taxa (levels) of classification
based on physical characteristics and
evolutionary relationships.
Kingdom
Phylum
Class
Order
Family
Genus
Species
Most inclusive
(biggest)
Most specific
(smallest)
Taxon
Bobcat
Lynx
Domain
Eukarya
Eukarya
Kingdom
Phylum
Class
Order
Family
Genus
Animalia
Chordata
Mammalia
Carnivora
Felidae
Lynx
Animalia
Chordata
Mammalia
Carnivora
Felidae
Lynx
Species
Rufus
Canadensis
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Dumb –
Kings –
Play –
Chess –
On –
Flat –
Green –
Squares –
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
1. Internal/external structures
 Fur, feathers, scales, etc.
 Vertebrate (backbone) or Invertebrate?
 Shape, size, color
2. Phylogeny
 The study of evolutionary relationships
among organisms
 Chromosomal comparisons
 Geographical distributions
 How close the amino acid sequences are in
proteins
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Method of grouping organisms together
according to their evolutionary history.
Biologists now group organisms into categories
that represent lines of evolutionary descent, or
phylogeny, not just physical similarities.
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is a branch of evolutionary classification that
uses derived characters to classify organisms.
Derived characters – characteristic that
appears in recent parts of a lineage, but not in
older species.
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A cladogram is a diagram that shows the
evolutionary relationships among organisms,
using derived characters.
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Biotic (living)
Size – bigger than viruses, smaller than
eukaryotes; unicellular
Kingdoms – Archaebacteria, Eubacteria
Nutritional requirements
 Archaebacteria – chemoautotrophic (use
chemical reactions to get energy)
 Eubacteria – autotrophic (cyanobacteria) and
heterotrophic (decomposers or pathogens –
disease causing parasites)
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Reproduce asexually by
binary fission
Binary fission occurs
when the bacteria
replicate their DNA and
divide into 2 identical
cells.
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Conjugation occurs when two bacteria cells
form bridges (called pili) between one
another and exchange genetic material.
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Endospores occur when growth conditions
are unfavorable. The bacterium forms a thick
wall that protects its DNA. Spores can remain
dormant for months or even years.
Structure
 Prokaryotes
 Cell membrane and cell wall of peptidoglycan
(eubacteria)
 Cytoplasm
 DNA and RNA
 Ribosomes
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Obligate aerobes – organisms that require a
constant supply of oxygen to live (Ex:
Mycobacterium tuberculosis the bacteria that
causes tuberculosis)
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Obligate anaerobes – organisms that must
live in the absence of oxygen (Ex: Clostridium
botulinum can grow in canned food that isn’t
properly sterilized)
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Facultative anaerobes – a group of bacteria
that can survive with or without oxygen (can
switch between cellular respiration and
fermentation
(Ex. E. Coli lives anaerobically in the large
intestine and aerobically in sewage or
contaminated water).
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Abiotic (not living)
Size – much smaller than bacteria (not made
of cells!)
Kingdom – none (not a living organism)
Nutritional requirements – no food required
Reproduces in a host cell through lytic or
lysogenic infection
Structure
 Particles of nucleic acid, protein, and
sometimes lipids
 Core made of DNA (RNA in retroviruses)
 Protein coat called a capsid surrounds the
core
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Most viruses are highly specific to the cell
that they infect. Plant viruses infect plant
cells; animal viruses infect only certain
related species of animals; and bacteria
viruses infect only certain types of bacteria.
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Bacteriaphages – viruses that infect bacteria.
Lytic infection – a virus enters a cell, makes
copies of itself, and causes the cell to burst.
 The host cannot tell the difference between
its own DNA and the viral DNA.
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The infected cell lyses (bursts) and releases
hundreds of virus particles that can go on to
infect other cells.
The host cell is destroyed.
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Lysogenic infection – a virus integrates its
DNA into the DNA of the host cell, and the
viral genetic information replicates along
with the host cell’s DNA.
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Lysogenic viruses do not lyse the host cell
right away. The virus remains inactive for a
period of time.
The viral DNA that is embedded into the
host’s DNA is called a prophage.
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Retroviruses – viruses that contain RNA as
their genetic material. When retroviruses
infect a cell, they produce a DNA copy of their
RNA, which is then inserted into the host’s
DNA. Retroviruses can remain dormant for
long periods of time.
Ex: Acquired Immune Deficiency Syndrome
(AIDS) is a retrovirus.
Pathogen
HIV/AIDS
Influenza (Flu)
Smallpox
Streptococcus
pyogenes (Strep)
Bacteria/Virus
Retrovirus
Effect on Body
Helper T cells, which
are needed for
normal immune
system function, are
destroyed
Pathogen
HIV/AIDS
Bacteria/Virus
Retrovirus
Influenza (Flu)
Virus
Smallpox
Streptococcus
pyogenes (Strep)
Effect on Body
Helper T cells, which
are needed for
normal immune
system function, are
destroyed
Body aches, fever,
sore throat, nasal
congestion,
headache, cough,
fatigue
Pathogen
HIV/AIDS
Bacteria/Virus
Retrovirus
Influenza (Flu)
Virus
Smallpox
Virus
Streptococcus
pyogenes (Strep)
Effect on Body
Helper T cells, which
are needed for
normal immune
system function, are
destroyed
Body aches, fever,
sore throat, nasal
congestion,
headache, cough,
fatigue
Fever, fatigue, rash,
head and back aches
Pathogen
HIV/AIDS
Bacteria/Virus
Retrovirus
Influenza (Flu)
Virus
Smallpox
Virus
Streptococcus
pyogenes (Strep)
Bacteria
Effect on Body
Helper T cells, which
are needed for
normal immune
system function, are
destroyed
Body aches, fever,
sore throat, nasal
congestion,
headache, cough,
fatigue
Fever, fatigue, rash,
head and back aches
Fever, sore throat,
swollen glands
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Biotic (living)
Size – bigger than bacteria; most unicellular,
some multicellular or colonial.
Kingdom – Protista
Nutritional requirements – autotrophic
(algae) or heterotrophic
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Have alternating two part life cycle: diploid,
spore forming sporophytes and haploid,
gamete forming gametophytes.
Structure – 3 groups: animal like
(protozoans), plant like (algae), and fungus
like.
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Your immune system protects you against DISEASE
 Disease
▪ any change, other than injury, that disrupts the normal
functions of the body
 Germ Theory
▪ States infectious diseases are caused by pathogens
(infectious agents)
▪ Ex. Viruses, bacteria, protists, worms, and fungi
2 Types of Immunity
1.Passive
-Get from outside source
-Ex: mother gives to fetus
-Ex: mother gives to baby
during breast feeding
2. Active
- When your immune system
works
-Ex. You get sick and your body
fights it off
OR after you get sick you don’t get
it again (like chicken pox)
-VACCINES!!
1. Nonspecific
- 1st line of defense
- Starts with skin and mucus to trap any pathogens
- Inflammatory Response
- Injury causes swelling and blood rushing to a wound
- Blood brings White blood cells (WBC) that “engulf” or
“eat” any foreign substance
- WBC actually roll along blood vessels until they get to a
wound, stop and start their jobs!
All antibodies look the same,
Except for the top of the “Y”
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AKA Immune Response
Triggered by Antigens:
foreign substance
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Humoral Response
 B-cells produce antibodies
 Antibodies then remove and
disrupt the antigen through
various mechanisms
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Cell Mediated Response
 Used against the body’s own
cells (Ex. Viral infected cells or
cancer)
 T-cells target “bad” cells and kill
them
T-CELL
INFECTED
CELL
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VACCINE
ALLERGIES
 Weakened form of a
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pathogen (disease)
 Your body then mounts a
similar response
 Once you develop
antibodies your body
“remembers” that
antigen and can quickly
respond a second time
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An “overreaction” of the
immune system to an antigen
Allergy causing agents attach to
special cells, called Mast cells,
and cause the inflammatory
response
Mast cells release histamines
which increase blood flow in that
area (in addition to mucus
production, sneezing and other
irritations)
Antihistamines are drugs that
counteract the histamine
produced by mast cells
histamine, releasing antigen
Mast
cell