Good Things Title Viruses Are Viruses Living or Nonliving Biologists consider viruses to be nonliving because Are not cells Do not grow or respond to their surroundings Cannot make food take in food or produce wastes ID: 796497
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Slide1
Warm up- 4/3
Other than bacteria, what can make us sick?
Slide2Good Things
Slide3Title:
Viruses
Slide4Are Viruses Living or Non-living?
Biologists consider viruses to be non-living because:
Are not cells
Do not grow or respond to their surroundings
Cannot make food, take in food, or produce wastes
Viruses do not respond to stimuli.
They can only multiply
in
another living cell
Slide5What are Viruses?
Definition-
Viruses are
non-cellular
particles made up of
DNA or RNA and
protein that can invade living cells.
Slide6Characteristics
Non-living
Non-cellular
Contain a protein coat called the
capsid
Have a nucleic acid
containing either DNA
or
RNA
Capable
of reproducing only when inside a HOST cell
6
Slide7What do Viruses look like?
Viruses are unusual and different from other things in nature.
Viruses come in a variety of shapes
Some may be helical shape like the Ebola virus
Some may be polyhedral shapes like the influenza virus
Others have more complex shapes like
bacteriophages
Slide8P
arts
of the
Virus
Head
Tail
Capsid
DNA/RNA
Tail fibers
Slide9Discovery of
Viruses
Beijerinck
(1897) coined the Latin name “virus” meaning poison
9
Slide10Tobacco Mosaic Virus
Wendell Stanley (1935) discovered viruses were made of nucleic acid and protein
10
Slide11Smallpox
Edward Jenner (1796) developed a smallpox vaccine using milder cowpox viruses
11
Smallpox has been eradicated in the world today
Slide12How can you catch a virus?
Exchanging bodily fluids
Insects and animals
Inhalation
Slide13Cycles
Lysogenic
Cycle
Viral DNA
May stay inactive in host for long periods of time
Long lasting
Lytic Cycle
Short and can be
treated quickly
13
Slide14PARASITISM
Viruses are parasites.
depends
upon another living organism for its existence
while it
harms that organism.
Slide15Herpes Virus
15
SIMPLEX I and II
Slide16Adenovirus
16
COMMON COLD
Slide17Influenza Virus
17
Slide18Chickenpox Virus
18
Slide19Papillomavirus
– Warts!
19
Slide20Vaccines
A weakened
form of the
virus which
will allow your body to better
fight it
off
when
exposed to the full
blown
virus.
Slide21Reducing the Risk
They can’t be treated but they can be prevented!
Cover mouth/nose when you sneeze of cough
Wash hands frequently
Avoid contact with the body fluids
Not foolproof but reduces the risks