Name ________________________________________________________________________________________Test Date_______________________
UNIT XI – VIRUSES & CLASSIFICATION
I. VIRUSES
 Living or non-living?
o Lack a ____________________________________
o Do not contain ________________________________ for ______________________________________
o Lack _________________________________ for protein synthesis
o DO contain __________________________________________________
o ___________________________________, although they require a __________________ cell
 Typically referred to as a ________________________ or _____________________.
A. Structure of Viruses
The following structures are found in all viruses:
 Genetic Material – The genome of a virus may be either _____________ or _________________, but never both. It can be
__________________stranded or _________________ stranded, _______________________ or _____________________.
 Protein Coat – The DNA or RNA is surrounded by a protein coat called a capsid. The proteins making up the capsid are
known as ________________________ and play an important role in the _____________________________ of the virus. In
addition, the capsid has __________________________ ID tags known as _______________________________ which can
______________________ to enable the virus to escape detection by a host cell’s immune system.
The following additional structures may be present:
 Viral Envelope – Many viruses have an outer membrane known as an envelope. A viral particle “steals” the components for
its envelope from the host cell membrane, so a viral envelope is primarily composed of ____________________________. It
aids in the attachment of the virus to the host cell, but a virus enclosed by an envelope is also more sensitive to __________.
Examples of viruses with envelopes are _____________________________________.
 Tail Fibers – Viruses that infect ______________________ are known as ______________________________. They have
“tail fibers” to aid in attachment.
B. Host Range
The host range of a virus is the range of host cells that it can infect. It is based on a complementary fit between viral
__________________________________ and receptor ____________________________ on the host cell membrane.
 Some viruses have broad host ranges which can include several species; for example, swine flu and rabies
 Some viruses have narrow host ranges where they infect only a single species; for example, the
_________________________________________ that attacks E. coli.
 Some viruses only infect a particular type of tissue or cell within a single species; for example the human cold virus infects only
cells of the __________________________________; HIV binds to receptors on certain ______________________________.
C. Viral Replication
A virus can infect a host cell and use it for reproduction in two ways:
 Lytic Infection – ____________________________ cycle in which virus ___________________________ host cell DNA.
Examples are ______________________________________________________________________________________
 Lysogenic Infection – ____________________________ cycle in which viral DNA is incorporated into __________________
___________________. Examples are ____________________________________.
There are two initial steps that are common to all types of viral infections:
1) Virus attaches to _____________________________ of ___________________ cell.
2) Virus releases ___________________________ into cell, either by ____________________________________________
cell or ________________________________ genetic material into it.
____________________ Cycle
…………………………………………………………………………………………………………………………………………………
_____________________________ Cycle
D. Viruses and Disease
All viruses are ________________________, meaning they require a living host and they cause harm to that host.
1. Herpesvirus – Group of viruses that are ____________________ and have many forms. Results in lifelong infections, although
virus can move back and forth from ________________ to _______________________ cycle. Group includes viruses that cause
cold sores, chicken pox, genital warts, shingles, and mononucleosis.
2. HIV - _________________________________________________ – Affects ________________ blood cells and immune system.
The HIV virus is a ______________________. Retroviruses contain __________ and the enzyme, ________________________
which allows the viral RNA to be __________________________________ into ____________. Initial symptoms are flu-like, then
virus enters ______________________________ cycle and replicates in lymph nodes, sometimes for years. When the HIV virus
becomes active, it causes _____________________ - Acquired ImmunoDeficiency Syndrome. Death of the patient results from
_____________________________________________________________________________________________________.
3. Human Papilloma Virus – Diverse group of DNA viruses; common cause of skin warts. Danger comes from group of sexuallytransmitted HPV which can cause genital warts, but more seriously, ___________________________________. Controversial
______________________________ has been produced; effective against most types of sexually-transmitted HPV.
4. Other viral diseases – hepatitis, influenza, smallpox, measles, common cold, rabies, Ebola
II. BIOLOGICAL CLASSIFICATION
Classification is the ___________________________________________________________________________________________.
Scientists classify organisms to _________________________________________________________________________________
__________________________________________________________________________________________________________.
The branch of biology concerned with the grouping and naming of organisms is called _____________________________________.
Taxonomy utilizes ____________________________________ relationships between organisms to correctly identify and group them.
A. Early Taxonomists
1. Aristotle – first taxonomist; organized living things into ______________________ & ______________________. Subdivided
according to their ______________________________________________________________________________________.
2. John Ray - a ___________________________; first used ____________________________________ for naming organisms.
3. Carolus Linnaeus – classified organisms according to their __________________________; called the “Father of Taxonomy”;
developed the modern system of naming known as ___________________________________________________. Binomial
nomenclature is the universal classification system used today in which groups are formed according to
____________________ ___________________ and then each organism is assigned a 2-word scientific name. The scientific
name is the ____________________ and ____________________ of the organism. The genus and species names are always
__________________________ or written in ____________________. ______________ is capitalized, _____________ is not.
B. Categories of Classification
1. Kingdom – broadest category, groups of closely related _____________________
2. Phylum – groups of closely related _______________________________
3. Class – groups of closely related _________________________________
4. Order – groups of closely related _________________________________
5. Family – groups of closely related ________________________________
6. Genus – groups of closely related ________________________________
7. species - ____________ and most similar group; organisms that share specific
characteristics and can ____________________.
C. Scientific Classification of a Human
Kingdom ________________________
Phylum ___________________________
Class ______________________________
Order ____________________________
Family ___________________________
Genus ______________________________
species _____________________________
III. THE EVOLUTION OF CLASSIFICATION
_____________________________, the science of classification, is a work in progress, in large part, because of evolution, both
as a science and a process.
A. Evolution As A Science – As the study of evolution becomes more sophisticated due to DNA sequencing, scientists are
realizing that organisms, or entire groups of organisms, have been ______________________________________________
1. The Kingdoms of Life
DNA analysis has had a major impact on the classification system, changing the long accepted system of 5 kingdoms to
_________ kingdoms. The two prokaryotic kingdoms, ______________________________________ and
____________________________ were originally classified together as Kingdom ___________________________.
2. The Three Domains of Life
Recently, further studies have led taxonomists to propose a classification system which includes three “super-kingdoms”
called _________________________________.
a. Domain Archaea – Includes the ___________________________________________________________________
b. Domain Bacteria – Includes all remaining prokaryotes or the ____________________________________________
c. Domain Eukarya – Includes the four eukaryotic kingdoms - ______________________________________________
IV. THE SIX KINGDOMS OF LIFE
A. Kingdom Archaebacteria
1. Cell Type - ______________________________________________
2. Cell Structure - ___________________________________________________________________________________
________________________________________________________________________________________________
3. Body Form - ______________________________________________________________________________________
4. Nutrition - _____________________________________________
____________________________________________________
5. Other characteristics – considered to be the most
_________________________________ of organisms; live in very
_______________conditions like ___________________________
temperatures, high ___________________ concentration, etc.
Another group of Archaebacteria live in the ____________________
system of animals and produce ____________________gas.
6. Examples - _____________________________________________
_______________________________________________________
B. Kingdom Eubacteria
1. Cell Type - ____________________________________________
2. Cell Structure__________________________________________
_____________________________________________________
_____________________________________________________
3. Body Form - ___________________________________________________________________________________________
4. Nutrition – Mostly ___________________________; some are ____________________________________________________
5. Other characteristics – Most _______________ bacteria. They are ubiquitous which means they are ___________________.
Very important _______________________. Some are ____________________, but most are __________________________.
6. Examples - ____________________________________________________________________________
C. Kingdom Protista
1. Cell Type - _________________________________
2. Cell Structure – May have ____________________;
may have ___________________________; may be
__________________________________ and have
______________________________________ or
_______________________________________.
3. Body Form – Mostly ________________________;
may be ____________________________________
4. Nutrition - _________________________________
________________________________________
5. Other Characteristics – Nicknamed “ ____________________________” kingdom or “_______________________________”.
Contains ________________ that don’t “fit” into other kingdoms. Protists are sub-grouped according to which
________________________ kingdom they’re most like; for example, _______________-like, _________________-like,
or ________________________-like.
6. Examples - ______________________________________________________________________________________
D. Kingdom Fungi
1. Cell Type - ____________________________________________________
2. Cell Structure – Have __________________ made of _________________. Fungi do NOT have __________________.
3. Body Form – Mostly ________________________________; may be ________________________________. Singlecelled fungi are known as ____________________________.
4. Nutrition – All _______________________________! Obtain nutrients through a process called __________________,
meaning food is digested _________________________ by secretion of ______________________, then absorbed by
fungi.
5. Other Characteristics – Principle ____________________. Also important in ________________and ______________.
6. Examples - ______________________________________________________________________________________
E. Kingdom Plantae
1. Cell Type - ________________________________________
2. Cell Structure – Have ________________________ made of
___________________; ______________________ present.
3. Body Form – All ___________________________________
4. Nutrition – All _____________________________________
5. Other Characteristics – Most contain __________________
and __________________________________________. All
__________________________________ with specialized
_____________________________________ structures.
6. Examples - ______________________________________
________________________________________________
F. Kingdom Animalia
1. Cell Type - ______________________________
2. Cell Structure – Never have ________________
________________________________
3. Body Form – All _________________________
4. Nutrition – All ___________________________
5. Other Characteristics – Most
_________________________ of all kingdoms.
Most organisms contain ___________________
and _______________________________. All
members are capable of ___________________
sometime during their lifetime.
Most animals are ________________________
meaning they _______________ a backbone. All
vertebrates belong to Phylum
_____________________________________
6. Examples - ____________________________
______________________________________
______________________________________