Classification of Organisms
_________________: the branch of biology by which scientists classify ______________ and give
each type a universally accepted name.
Remember in order to be considered an organism certain characteristics must be met. Organisms must:
1. Be composed of 1 or more ________
2. Perform certain _________________________ like growth and digestion
3. ________________
4. Make their own _______________ or ingest nutrients from __________________
5. Respond to ______________ such as light or touch
How organisms are named:
_____________________ became necessary as the known number of organisms increased with world
travel. Common names vary between languages and regions; because most scientists understood ________
and _________, these languages are used to this day in naming organisms.
The naming system used today is called ____________________________________. It was
developed by __________________________ in the 18th century. This system gives each _______
(a population of organisms that share similar characteristics and can breed with one another to produce fertile
offspring) a ___________ scientific name:
Carolus Linnaeus
Scientific naming rules:
1) Scientific names are written in _________ when
typed or underlined if written by hand.
2) The first name is the __________ name. A genus is a
group of closely related species. The first letter of the genus
is always capitalized.
3) The second name is the _________ name. It is
always a Latin name that is descriptive of some
characteristic of the species.
Example: Ursus maritimus is a polar bear. Ursus is the
genus name. maritimus is the species name. It refers to
the sea as polar bears live on ice that floats in the sea.
Our current system is composed of 8 levels:
domain, kingdom, phylum, class, order,
family, genus, and species.
Each of these levels is called a _________ (sing.)/taxa (pl.)
Organisms become more similar as you
move from kingdom to species.
Note figure 1.3 on page 506 of your
textbook.
Limitations of the Linnaeus system of classification: Linnaeus grouped organisms according to visible
similarities or differences. Remember physical similarities are not always a result of a close relationship
between species. For example the giant panda and ____________ have similar ears and snouts however
molecular biologists have found that the giant panda is more closely related to members of the _______
family than raccoons. This problem has given rise to a second method of classification:
Evolutionary Classification: the strategy of grouping organisms according to believed evolutionary descent
(_______________). The idea is that members of a genus all share a common, more recent,
____________. A family would share a common, less recent ancestor, etc.
The most common method used to show evolutionary
trees is to design a _____________ based on
patterns of shared derived traits. (We studied these last
unit, so you should know how to read one by now.)
Molecular Evidence: New technology allows
biologists to compare groups of species at the
______________ level by comparing their _____
sequences. Scientists look at __________ and
________ to compare organisms as well.
Ex. DNA electrophoresis
Modern Groupings:
Our current method of
classification includes
3 domains:
1) Bacteria
2) Archae
3) Eukarya
-and_____ kingdoms:
1) Bacteria
2) Archae
3) Protista
4) Fungi
5) Plantae
6) Animalia
Identifying unknown organisms: The identification of biological organisms can be greatly simplified using
tools such as _________________________. It is a written set of ___________, each
involving ________________________, that leads to the _________ of an organism. Scientists use
these to identify unknown organisms.
W
Practice:
W= _______ goby
X
Y
X= ________ goby
Y= ________ goby
Z= ________ goby
Z
Bacteria
The Archaea and Bacteria ______________ encompass relatives of the ___________ organisms on
Earth. They are highly diverse because of all the time they have had to __________ and differentiate. These
organisms are everywhere. They are on everything you touch and ingest. In fact, there are billions of bacteria in
your intestines right now!
The members of both ________ and __________ have several
similarities. For one, they are all ______________. This means,
they are all one-celled and are absent of a true nucleus. Their DNA is
contained in a single, twisted chromosome that stays in a ________
region or is simply floating free in the cytoplasm. They generally lack
_____________, though some exceptions have ____________.
All have relatively thick ______________ to hold them together.
Although these two domains have similarities, they are two separate
domains for a reason.
Archaea vs. Bacteria
Prokaryotes were originally under one domain: Bacteria. However, in 1977, Carl Woese, a microbiologist and
physicist discovered significant differences between some of the prokaryotes. These differences were so
significant that the prokaryotes were separated into two separate domains: __________ and
_____________, and hence two _____________: Archaea and Bacteria.
What makes these two groups of organisms so different is their ____________ make-up, primarily the
________ sequences of ___________________ (rRNA). Woese found that archaean biochemistry was
more similar to that of _______________—multi-celled organisms—than that of eubacteria. In particular,
there were similarities with the enzymes involved with transcription and translation of DNA and with several
metabolic pathways. The cell membrane of archaea is also unique from that of eubacteria, possessing unusual
________. Amongst this significant genetic difference, there are many other differences between these two
groups of organisms.
Kingdom Archaea Characteristics
 ____________ microbes
 Ancestors of protists
 Obtain most of their energy from ___________, salt, hydrogen & ___________________
 Tolerant of ____________ environmental conditions
o ________________
 _______________- intolerant of oxygenated areas
 produce _____________ gas
 thrive in __________, mud, carcasses of animals, and even your ____________!
o ___________________
 ______ lovers
 live in waters with high salt concentrations, like the ______________ in the Middle
East or the _________________________ in Utah.
o _______________________
 can survive temperatures as high as _____°F
 can survive ______ levels below 2 (hydrochloric acid pH=1).
Roles of Archae in Ecosystems
 _______________- break down dead organisms returning nutrients and gases to the environment
 _______________ relationships like mutualism and commensalism
 Helpful in __________________ cycles, recycling vital elements like nitrogen, carbon, and sulfur.
 Biotechnology efforts- used to break down ________ to produce bio-gas that can be used to generate
electricity
 Contribute to ___________ and ______________________. Methane gas is a main source
of greenhouse gases, and methanogens are the number one producers of it.
Kingdom Bacteria Characteristics
 Thrive in a wider variety of environments- your _______, your ________, & your ________
 Can be decomposers, ______________ or ______________
 Some eubacteria have the ability to form ______________ and "hibernate"—in other words, they
become metabolically inactive until conditions improve. As lightweight spores, they are able to float in
the air and move all over.
 Some are ______________ while others have ____________ that move them along.
 Some are photoautotrophs that can make their own food through ___________________. They
have a chain-like structure and are commonly found in moist areas like lakes and ponds.
o Autotrophs indicate that eubacteria are ancestors of ___________.
 There are also ________________—bacteria that get their energy from chemical compounds.
Roles of Bacteria in Ecosystems
 Decomposers
o Clostridium botulina are decomposers that act fast on some food items, releasing a powerful
poison. If you ingest these bacteria, you are most likely to get ___________________.
 Producers
o __________________ grew in the _______ over 3 billion years ago and were
responsible for adding ___________ into our developing atmosphere.
 Bioremediation- use microbes to break down pollutants like _________________
 Biotechnology efforts
o Assist in the treatment of _____________
o Used in production of ____________ and _____________.
 Can be ______________-disease-causing germs that harm other organisms.
o Cause infectious diseases like cholera, syphilis, and tuberculosis
 Mutualistic relationships
o For example, Escherichia coli, or __________, are a type of eubacteria that live inside our
________. They help absorb ________ and break down vitamins. In return, these bacteria
are provided with a comfortable environment and a consistent supply of nutrients by us.
o Some soil bacteria conduct _____________________________.
 Capture ____________ gas from the atmosphere and return it to the _______
 Convert nitrogen gas to ______________ that plants can absorb to form proteins
 ____________________ have the ability to fix atmospheric nitrogen as well
Identification of Bacteria
 Identifying an organism as an archaean is mainly done by studying its ____________________.
o Differences in rRNA remain the main classification
characteristic.
 Only bacteria have the peptidoglycan polymer (made of sugars and
amino acids) in their cell walls
 Shape of the cells
o ____________ (round)
o ____________ (rod-shaped)
o ____________ (spiral-shaped)
o in archaea, spherical, square, rod, and triangular shapes

Arrangement of cells:
o ___________
o ___________ (staphylo-)
o ___________ (strepto-)
o ___________ (diplo)



____________________________ (identifier for Kingdom Bacteria only)- The make-up of the cell plays
a role in the effectiveness of different ________________.
o Gram-positive bacteria
 _________ peptidoglycan layer that absorbs the stain
 __________ appearance under the microscope.
 respond to penicillin
o Gram-negative bacteria
 _____ peptidoglycan layer that will not accept the stain
 _____ or pink appearance
 respond to tetracycline
Nutritional requirements: how they gain __________ and nutrients
Ways of moving- corkscrew motion, gliding, or propelling with
____________.
Bacterial Reproduction
Most bacteria reproduce asexually, by _________________, in which the cell divides into two equal
halves. At times, the genetic material between bacteria can be recombined, or shared. Genetic recombination
methods include:
 ________________ – involves the exchange of genetic material between individuals by contact
 A virus may carry DNA material to bacteria in the process of ___________________.
o Genes from a bacterial host cell are incorporated into the genome of a virus that plagues bacteria
and are then transmitted to another bacterial cell as the virus invades it.
 _________________ can occur when bacteria is exposed to DNA remnants of dead bacteria.
Treatment of Bacterial Infections
People suffering from bacterial infections are treated with ______________. Antibiotics are substances,
such as ________________, that are produced by certain fungi, bacteria, and other organisms that can
destroy or ___________ the growth of other microorganisms.
Viruses
Viruses are ______________ submicroscopic particles and can only be examined in detail by using an
___________ microscope. They are known ________________ (disease-causing particles).
Characteristics of Viruses
 Are not composed of _______
 Very _______
 Do not respond to _________________
 Lack enzymes for _________________ therefore do not eat
 Do not use ___________ for growth and development
 Contain either _____ or _______, but not both (bacteria have both).
 Nucleic acids are enclosed in a protein coat called a ___________.
o This coat may be rod-shaped, polyhedral, or more complex in shape.
o The most complex capsids are the ______________________
 Bacteriophages are viruses that infect _____________ such as E. coli



Do not duplicate themselves outside of a cell. They are able to replicate only within cells.
Have no _________________ for protein production
Viruses are divided into two groups for classification based on the nucleic acid they contain
o DNA viruses
o RNA viruses, also known as __________________- reverse the normal flow of genetic
information from DNA to RNA by transcribing RNA into DNA
 ______________________________ (HIV) is an example of a retrovirus.
 Many cause _____________ in animals
Viral diseases are among the worst diseases that affect humans. Epidemic influenza (flu), colds, ebola, German
measles, mumps, polio, rabies, herpes, genital warts, chicken pox, and many other diseases are caused by
viruses.
Viruses vs. Bacteria
Viruses are much ___________ than bacteria. Unlike bacteria, viruses are not true living
______________ because they are not made of ________. Viruses are bundles of genetic material or
information enclosed in a _________. They are unable to reproduce themselves and must rely on a host cell
for replication. Viruses are like cell hijackers. They inject their ________ (either RNA or DNA) into the
nucleus of a cell and make it create new viruses. Eventually the build-up of viruses causes the host cell to burst,
releasing the new viruses.
Like bacteria, viruses are found just about everywhere on _________. They are able to infect every form of
life on the planet, from blades of grass to humans. Although viruses cannot survive very long without a host,
they can remain inactive on _____________ surfaces such as countertops and doorknobs. Once picked up
by a living host, the virus becomes __________. Viruses can be contracted through _______, water,
________________, and direct contact. Unlike bacterial infections, many viral infections cause no
____________. Often people do not even know they are infected. Viral infections cannot be treated with
_________________ like most bacterial infections can be. In fact, most viral infections have no
treatment at all. Instead, there are _________________ methods for blocking a virus.
Viral Reproduction
A virus _______ infect a cell and take over the cell’s metabolic machinery to reproduce. An isolated virus is
unable to do __________________ without a host cell.
To start with, the virus has to __________ the cell. So the virus attaches itself to the outer
______________ and releases _____________ that weaken the cell wall. Then, depending on
whether it is a DNA virus or a RNA virus, the virus injects its double stranded ______ or its single stranded
_______ into the cell. There are 2 different ways that these viral infections can then spread—through the
________ or __________________ cycle.
The viruses that cause _______, mumps, ______________, & ________ are examples of viruses that
follow the lytic cycle. These viruses produce short-lived infections. In the lytic cycle, the virus hijacks the
infected cell and then ____________ it.
Steps of the lytic cycle
1. Tail fibers __________ to cell
2. Virus ____________ DNA into cell to take over the cell’s DNA
3. Host cell is reprogrammed to ______________ the viral genes
4. New proteins _____________ around new viral DNA to form new viral particles
5. New viral particles ____________; cell is destroyed
The viruses that cause _________, ______, hepatitis, and chicken pox follow the lysogenic cycle. In the
lysogenic cycle, the viral DNA or RNA enters the cell and integrates into the host DNA as a new set of genes
called ___________. That is, the viral DNA becomes part of the cell's genetic material. Each time the host
cell’s __________________ replicate during cell division, the ___________ prophage replicates too.
This may alter the cell's characteristics, but it does not destroy it. There are no viral ______________ in
the lysogenic cycle; it occurs after the viral infection is over. But the viral DNA or RNA remains in the cell and it
may remain there ________________. However, if the prophage undergoes any ________ or
____________ or is exposed to ____________________, the viral lysogenic cycle can change into
the viral lytic cycle. In which case, there will be symptoms of a new viral infection.
Steps of the lysogenic cycle
1. Tail fibers attach to cell
2. Virus injects DNA
3. Viral DNA becomes part of cell DNA (this is a provirus; no interference w/normal cell function)
4. Provirus is replicated along with host cell’s DNA
5. Can remain in this stage for years! May enter lytic stage when conditions are favorable
Some viruses first replicate by the lysogenic cycle and then switch to the lytic cycle.
Vaccinations and Immunizations
In 1796, an English doctor named _____________________ discovered a technique to treat
__________________, a highly contagious and sometimes fatal disease. Smallpox is caused by the
variola virus. Symptoms include high fever, painful ______, and fatigue. Jenner was a country doctor who
often treated dairy maids for cowpox, a mild viral infection contracted from cows. Curiously, dairy maids who
were infected with cowpox never contracted smallpox. Jenner hypothesized that cowpox provided
_____________ against smallpox. He tested his theory on an eight-year-old boy named James Phipps.
Jenner deliberately infected James with cowpox and then exposed the boy to smallpox. Thankfully, James did
not contract the disease. After repeating the experiment on other children, including his own son, Jenner went
public with his discovery.
His technique became known as ________________. The term comes from the Latin word vacca,
meaning "cow." Today, vaccination is the most successful protection against diseases caused by viruses.
According to health officials, vaccination prevents over two million deaths worldwide each year.
Vaccination works in one of two ways. In most cases, a ____________ or inactive form of a virus is injected
under the skin. Since the virus is in a weakened form, few to no ____________ occur. The immune system
responds by producing specific _____________ for the virus. These antibodies remain in the body,
providing immunity to future exposures to the virus. The __________ is an example of this type of
vaccination. In some instances, ___________ from donated ________ are injected under the skin. These
antibodies provide protection for many diseases, such as German measles, _______, and ____________.
Protists
A ___________ is any organism not classified as a plant, animal, fungus, or bacterial cell. They belong to
the Domain _______________ with all other eukaryotic organisms and the Kingdom ____________.
Protist Characteristics
 Eukaryotic- true ___________
 Some have cell walls made of ____________
 Some have _______________
 Most are _______________, but they may be colonial.
 Some are even __________________
 Can be ______________ or heterotrophic
Three main categories of Protists:
1. Animal-like
2. Plant-like
3. Fungus-like
Animal-like Protists
 Also called __________________
 ______________ - get energy from other organisms
 Can _________ to obtain food
 Made of cells with a _____________ and no cell wall - just like an ____________ cell
 _____________ – made up of one cell
4 Main Groups of Animal-like Protists
1. ________________
 Move to obtain food using ______________ (“false feet”) – temporary bulging/extensions
of the cell that are used to capture and engulf food and used to move
 Have a _____________ vacuole - structure that collects and expels extra water from the cell
 Example – Amoeba
-Amoeba proteus- Most well-known amoeba. Was named for the Greek god of the sea, Proteus,
that could change _________!
-Entamoeba- parasitic amoeba that causes amebic dysentery (severe diarrhea). Spread through
contaminated ________; attacks the large intestine where it may cause bleeding
2. Ciliates
 Use _______, hair-like projections from the cell that
move with a wavelike motion, to move and eat
 Cilia help sweeps food into the __________ until a food
vacuole is formed
 Ex. Paramecium
3. _____________________
 Use ___________ (whip-like tail structure) to move
They can have one or more flagella
_____________ food through cell membrane
Ex. Trypanosoma- causes African Sleeping Sickness. Carried to its host by the
____________. Causes chills, rash, and nerve damage leading to deep sleep and death.
4. ___________________

Do not move at all

______________-feed on the cells and body fluids of their ________

Ex. Plasmodium- causes _____________. Carried by the Anopheles mosquito. Organism
enters the host by the mosquito’s saliva and attacks the liver and blood cells causing the cells to
rupture; leads to high fever, _____________ and nausea



Plant-like Protists
 Commonly called __________
 Autotrophic - use the sun’s energy to produce their own ________
 Some are unicellular
 Some are multicellular
7 Main Types of Plant-like Protists
1. _________
 VERY IMPORTANT in ____________ production!
 Most live in __________, some on damp surfaces
 All algae contain ____________________ and photosynthesize
2. ___________
 _________________ protists that have glass-like cell walls
 Float near the surface of lakes and oceans
 Move by oozing chemicals out of slits in their cell walls
 Used in household scouring products and ___________________
3. __________________________
 Unicellular algae surrounded by stiff _______
 They come in a variety of colors (many glow in the dark)
 All have two ________________
 Responsible for "__________________" (algal bloom)
i. Usually in coastal areas.
ii. Result of rapid accumulation of dinoflagellates in the water column.
iii. Have the potential to kill fish, birds, marine mammals, and other organisms with toxin
4. _________________
 ________, unicellular algae found mostly in fresh water
 Use _____________ for movement
 More similar to animal-like protists as they have no _____________
 Have a thickened cell membrane called a ______________
 Can be autotrophs or heterotrophs
 Have an ______________ that helps organism find sunlight for photosynthesis
 Ex. Euglena
5. __________________
 Multi-cellular seaweed
 Only needs a small amount of _________________
 Used in hair conditioner and ice cream
 Contains red chlorophyll, which gives it its color.
6. ___________________
 Contain green pigments
 Unicellular, multicellular or ______________ –organisms live attached to others
 They are closely related to plants
 Ex- Ulva sea lettuce
7. ____________________

Seaweed with many pigments

It has many plant-like structures

Ex- Sargassum _______________ and Giant Kelp
Fungus-like Protists
 ___________________ that absorb nutrients from dead or decaying matter
 Have __________________
 Have cell walls lacking ____________
 They use ____________ to reproduce- tiny cells that can grow into a new organism
2 Main Types of Fungus-like Protists
1. _______________________
 Brightly colored
 Live in moist, shady places like damp mulch beds
 They are tiny in size to as big as several meters
2. _______________________ and Downy Mildew

Most live in water on decaying ___________

They grow in tiny threads that look like fuzz

Ex. Phytophthora infestans responsible for ______________________
Roles of Protists in Ecosystems
 Symbiotic relationships-Trichonympha protist lives in the gut of _____________. It produces the
enzyme ___________ that allows the termite to digest ___________.
 Can help decompose matter and return ______________ to the environment
 Base of the ____________________
 Producers of ___________________
Fungi
__________ belong to the Domain _______________ and the Kingdom _________. This kingdom
includes ______________, _____________, truffles, molds, yeasts, and thousands of other organisms
and microorganisms. They range from microscopic single-celled organisms, such as _________, to gigantic
multicellular organisms.
Fungi Characteristics
 Grow ________________ – air, water, in gardens, on foods, etc.
 Most are ________________, but some unicellular like yeast
 _________________
 Lack true roots, stems, & leaves
 Some are edible
 Non-motile
 Reproduce by sexual & asexual ___________
 Cell walls are made of ___________ (a complex polysaccharide)
 Grow best in warm, ________ environments preferring shade
 Do not contain chlorophyll so non-photosynthetic
 Absorptive ____________ - digest food first & then absorb it into their bodies
 Release digestive enzymes to break down organic material or their host
 Most are _____________ – live on other dead organisms
 Grow as microscopic tubes or filaments called ___________ that contain cytoplasm & nuclei
 Hyphal networks are called _______________
 Some are internal or external parasites that use specialized hyphae called ______________ to
absorb nutrients from living cells
Roles of Fungi in Ecosystems
 Important ______________ & recyclers of nutrients in the environment
 Antibiotic ____________ comes from Penicillium mold
 Yeasts are used to make _________________________
 ________________ eaten as food
 Help form _____________________
 Aspergillus is used to make ____________________

Symbiotic relationships:
o __________—mutualistic relationship between a sac fungus & a photosynthetic green algae
or cyanobacteria Both organisms ___________ (algae makes food & fungus supplies
moisture, shelter, & anchorage)
 Grow on rocks, trees, buildings, etc. & help form _______
 ____________ lichens grow on rocks & trees; ____________ lichens grow
shrub-like; ___________ lichens grow mat-like on the soil
o ________________--Symbiotic association of a fungus living on plant ________;
fungus absorbs ___________ made by plant; plants absorb more water & minerals with aid
of the fungus
Fungal Infections
 Athletes foot
 Onochomychosis- nail fungus
 Yeast infections
 Ringworm
 Jock itch
 Madura Foot Fungal Infection
 Aspergillus flavus