To Do Today
Mon May 5
Organize notebook
Begin notes on
viruses
Warm Up What do you know
about viruses?
Explain.
Fact: Most of us have harmless microscopic
mites living in our eyebrows.
Tue May 6
To Do Today
Organize notebook
Begin notes on viruses
Warm Up What is a pathogen.
Fact:
Most experts believe that flu viruses spread mainly by
droplets made when people with flu cough, sneeze or talk.
These droplets can land in the mouths or noses of people
who are nearby. Less often, a person might also get flu by
touching a surface or object that has flu virus on it and then
touching their own mouth, eyes or possibly their nose.
Table of Contents for Quarter 4 Bio
Page
Assignment
Number
1
Table of Contents
2
Foldable: Introduction to Plants
3
Active Reading : kinds of plants
4
Vocabulary Review Plants
4b
3
Seeds: Drawing and Labeling – pumpkin and sunflower
5
Pine Cone Facts ½ sheet
6
Gymnosperms Reading
7
Gymnosperms Activity – puzzle and fill in blank
8
Flower Lab Activity
9
Leaf handout
10
Review for Botany Test
11
Bill Nye Plants Handout
12
Viruses Vocabulary – Terms from book pg. 434
13
Virus Foldable
Virus and Bacteria – Unit # 3
Virus Vocabulary Terms
Put onto notebook paper onto page 12 of
notebook -- Text book pg. 434
•
•
•
•
•
Virus
Pathogen
Capsid
Envelope
Glycoproteins
•
•
•
•
•
Bacteriophage
Lytic
Lysogenic
Prions
Viroid
Viruses
Create foldable for notes
Need to pick up
• 2 sheets of
white paper
• ½ sheet
• Viral diseases
handout
Virus video: http://www.youtube.com/watch?v=Rpj0emEGShQ
What is a Virus
A virus is a small infectious agent that can replicate
only inside the living cells of organisms. Most viruses
are too small to be seen directly with a light
microscope. Viruses infect all types of organisms, from
animals and plants to bacteria and archaea.
Since the initial discovery of tobacco mosaic virus
about 5,000 viruses have been described in detail,
although there are millions of different types. Viruses
are found in almost every ecosystem on Earth and are
the most abundant type of biological entity. The study
of viruses is known as virology, a sub-specialty of
microbiology
6
To Do Today Wed/Thurs May 7&8
• Virus Notes in foldable
http://cellsalive.com/howbig.htm
• video: Life Science:
Virus
• Viral avengers
Warm Up –
In your own words:
What is a virus?
microorganism that cannot reproduce without
a host cell. It inserts genetic material into the
cell and takes over its function.
What is a virus?
brainpop virus: http://www.brainpop.com/health/diseasesinjuriesandconditions/viruses/
• is not a living organism
• is non-cellular
• Consists of a nucleic acid core (DNA or
RNA) and a protein coat called a
capsid.
• Cannot grow or replicate on their own.
Pathogen-agents that cause disease
Viruses do not grow, do not have
homeostasis and do not metabolize
8
Discovery of Viruses
Near the end of the nineteenth century, scientists were
trying to find the cause of tobacco mosaic disease, which
stunts the growth of tobacco plants. When scientists
filtered sap from infected plant they noticed that the sap
could still cause uninfected plants to become infected. They
called this a virus which in latin means poison. For many
years they were thought to be tiny cells.
In 1935, biologist Wendell Stanley of the Rockefeller
Institute purified tobacco mosaic virus (TMV) and found
that it crystallized, therefore it could not be living.
Wendell Stanley concluded that TMV (a virus) is a chemical
rather than an organism.
Discovery of Viruses
Virology- Study of viruses
Viruses have existed as long as life has been
on earth.
1.Martinus Beijerinck- (1897) Coined
the name – virus meaning poison
2. Wendell Stanley (1935) Crystallized sap
from the Tobacco leaves infected with
tobacco mosaic virus
and found a virus made
of nucleic acids and
protein
10
3. Edward Jenner – Developed small pox vaccine
using milder cow pox viruses
Vaccine – contains an agent that resembles a disease
causing microorganism
Structure of Viruses
3 types
1. Plant viruses- usually helical and rod like
in appearance proteins winding around
a core of RNA or DNA
2. Basic animal Virus Structure – spherical and
studded with receptors
*some viruses can
be Polyhedral
meaning has
MANY sides can be
as many as 20
triangular faces
with 12 corners.
3. A bacteriophage is a virus which
infects bacteria. These viruses
typically cause their hosts to die as
a result of infection, which makes
bacteriophages of great interest to
the medical community and to
scientists who cultivate bacteria. In
industries where bacteria are
harnessed to perform tasks such as
the fermentation of foods or the
production of useful chemicals,
contamination with bacteriophages
is a major source of concern, as the
viruses can bring a process to a
complete halt.
Viral Reproduction
Viruses are not living cells; viruses lack the capacity
to metabolize on their own. Viruses MUST rely on
living cells (host cells) for replication
• Before a virus can replicate, it must INFECT the
living cell.
• EXAMPLE: An animal virus enters its host cell
by endocytosis.
Bacterial virus, “bacteriophage,” punches a hole
in the bacterial cell wall and injects its DNA into
the cell.
How viruses invade your body:
http://www.youtube.com/watch?v=Rpj0emEGShQ
There are 2 pathways a virus can take in order to
replicate itself; Lytic Cycle or Lysogenic Cycle
1. Lytic Cycle
Step 1 Attachment: Virus attaches to cell,
Step 2 Injection: Virus injects DNA or RNA
(nucleic acid) into cell
Step 3 Replication: Host cell replicates viral
genes & viral proteins (A.K.A. Capsid Proteins)
Step 4 Assembly: Nucleic acid and proteins
assemble to form a complete virus
Step 5 Release: Host cell bursts open,
releasing a NEW virus
Lytic Cycle
2. Lysogenic Cycle
Some viruses stay inside a cell, spreading
its virus through a cells natural
reproduction
• Lysogenic cycle allows the viral
genome to replicate without
destroying the host cell. In some
lysogenic viruses, environmental
changes can cause the lysogenic
cycle to begin.
• A virus in the lysogenic cycle
can switch to the lytic cycle
Example: Cold sore virus; virus hides in
facial nerves. When body conditions are
favorable (ie. Stress, sick, body weakened),
the virus will cause tissue damage resulting
in a cold sore or fever blister
2. Lysogenic Cycle
Step 1 Attachment: Virus attaches to cell
Step 2 Injection: Viral gene is inserted into host
chromosome
Step 3 Integration: Viral genes (DNA or RNA)
combines with host DNA to become one
Step 4 Cell Multiplication : Host cell divides
normally, resulting in 2 new cells, each containing
viral DNA.
*NO damage to the host cell*
* The new cells, containing viral genes, can
switch to the Lytic Cycle to create MORE
viruses*
Lysogenic Cycle
song
“I’m a VIRUS!”
• http://www.youtube.com/watch?v=kYf_Sl8W
3qY
To Do Today
Fri May 9
*Outbreak video with handout
Warm Up Complete reflection
– Turn in
So viruses
make
sick,
•What
is the Latinus
meaning
for
virus?
what
else
•Name one
person responsible
for discovering viruses and
makes
explain
what they us
did. sick?
Homework:
Any Missing
BACTERIA
virus which in Latin means poison
Martinus Beijerinck-na
Wendell Stanley- TMV
Edward Jenner-small p
Jonas Salk-polio vacci
work due May 16!