Viruses and Bacteria

Chapter 18: Viruses and Bacteria 

Battlefield Cell Video

Essay Prompt: Explain the Procedure of Infection of this Virus

How does this virus spread?

What classifies organisms as living?
Are viruses alive?
What makes up a virus?
How do viruses replicate?
What are some examples of viruses?

Viruses are not considered living because they do not meet these characteristics...but once in a host they hijack the its machinery to create more of the virus.

Many viruses have a similar composition of protein and nucelic acid. (some have a lipid coat)

A viruses can replicate using 2 cycle processes:
Lytic Cycle where the cell bursts, killing the host cell.

Lysogenic Cycle where the viral DNA is integrated into the host DNA. External factors (stress conditions) may trigger the virus into going into the Lytic Cycle.

What are some examples of viruses?

Ebola: fatality rate of up to 90%, the Ebola Virus Disease (also called Ebola Hemorrhagic Fever) is believed to be one of the deadliest virus infection all over the world.

 

Rabies Virus: causes 55,000 human deaths each year, if left untreated 100% fatality rate.

Smallpox Virus: very few deaths due to a vaccine but if patients contract the virus 90% fatality rate .

Chickenpox Virus: (varicella) used to be very common in the United States before the chickenpox vaccine became available in 1995. In the early 1990s, an average of 4 million people got chickenpox, 10,500 to 13,000 were hospitalized (range, 8,000 to 18,000), and 100 to 150 died each year.

HIV: this virus has claimed the lives of millions. In many cases if no treatment/medication 100% fatality.

SARS: Severe Acute Respiratory Syndrome about 10% fatality rate.

Rhinovirus

How do you get the Common Cold

Influenza

Avian Flu

Viroids: nucleic acid molecule that infects plants

Prions: protein molecule that infects the hosts neurological system
Mad Cow Disease

Zika virus

Are you controlled by viruses

Prokaryotes

Characteristics:

• no membrane bound organelles
• free floating DNA in circular form and/or a plasmid (separate part of DNA)
• unicellular
• motile (movement) by use of flagella and/or pili

Groups of Prokaryotes

• Obligate anaerobes can not survive in the presence of O2
• Obligate aerobes must have O2 to survive
• Facultative aerobes are can survive in the presence or absence of O2.

Archaebacteria vary in shapes and live in extreme environments

There are 3 types of structures of Eubacteria.

Rod shape - Bacilli 

Spiral shape - Spirilla

Spherical shape - Cocci

Reproduction/Conjugation

Bacteria reproduce sexually using their pili

They can also reproduce asexually through  BINARY FISSION.

Gram Staining

Gram Negative Bacteria have the extra layer of protection which makes them harder to treat. Their cell walls are resistant to several classes of antibiotics.

Benefits/Treatments

Some bacteria inside our bodies are beneficial. They help organisms breakdown food. Some make vitamins and other compounds.

They have a mutualistic symbiosis with organisms. Bacteria breakdown food and keep them healthy, while organisms protect them.

Bacteria can be treated with Antibiotics. 

Brainpop

Amoeba Sister's Prokaryotes Review

EXAMPLES

E.coli & Salmonella= cause food poisoning

 

H.Pylori= cause ulcers and gastritis

Staphylococcus aureus= causes a variety of infections in the body, including boils, cellulitis, abscesses, wound infections, toxic shock syndrome, pneumonia, and food poisoning

Streptococcus pyogenes = strept throat

Nactrotizing fasciitis = Flesh eating bacteria

 

Leprocy

Bringing Awareness To A Pathogen

Classification

Assignments due Thursday: Chapter 17 IR & Vocabulary...No Late Work Will Be Accepted and Do Not Copy!!

STAAR Practice Questions

1.The Linnaean taxonomic system classifies organisms into divisions called taxa. If two organisms belong to the same taxonomic group, they are related. Similarity at which of these levels indicates the closest relationship?

F Kingdom
G Class 
H Order 
J Genus


Chapter 17:
The Linnaean System of Classification

What are the common names for this animal?

Carolus Linnaeus 

Developed a system of classifying and naming of living things which made it easier to identify and classify new organisms.

The science of naming and classifying organisms is known as TAXONOMY. Each group of organisms is called a TAXON (TAXA for plural)

Why the weird names?

The first part of the scientific name is known as the Genus and is always capitalized...Homo

The second part of the scientific name is known as the Species and is always lowercase...sapien

Which one is the least related organism?

• Ursus americanus
• Ursus arctus
• Ursus maritimus
• Ailuropoda melanoleuca 

Who is this organisms closest relative?

Ailurus fulgens

A) Procyon lotor

B) Ailuropoda melanoleuca

C) Thylamys pallidior

In order to classify organisms correctly a dichotomous key must be developed

Practice Classification 

The system of the Linnaeus classification system has 7 Levels.....Domain was added later. 

What would you imagine if I said "I captured a animal in my backyard and kept it in a box with its friends."

It would be more specific on my part to say "I captured a fire ant  (Solenopsis mandibularis) in my backyard and kept it in a box with its friends."

I went from something very broad ANIMAL to very specific FIRE ANT

Today scientists agree that organisms should be classified based on evolutionary relationship and not just physically.

For this Cladograms are used.

Each have traits shared by some and not others known as Derived Characters.

Nodes are where the branch splits.

Molecular Clocks are used to trace mutation rates to measure evolutionary time.

There are 3 main domains of life Bacteria, Archae, and Eukarya

Within these domains are the 6 kingdoms

Eukaryotes
1. Animalia
2. Plantae
3. Fungi
4. Protista

Prokaryotes 
5. Eubacteria
6. Archaebacteria

Leaf Identification Activity

Scale-like              Serrated