Exam 1: Viruses, Bacteria & Archaea, Protists, Fungi

Question 1

taxonomy

Answer 1

the practice and study of classification of things or concepts + the principles that underlie such classification OR putting things into diff categories as a means of organization

Question 2

two main schools of thought

Answer 2

lumpers - group critters into as few groups as possible

splitters - split critters into as many groups as possible

Question 3

taxonomic hierarchy

Answer 3

domain kingdom phylum class order family genus species

dumb king philip can only find green socks

Question 4

taxa

Answer 4

a group of critters at a given taxonomic level

Question 5

species

Answer 5

a group of like critters that can reproduce and produce viable offspring

Question 6

classification systems/historic people

Answer 6

aristotle - 4th century greek philospher, grouped into plants and animals, divided animals into blood and bloodless, divided animals into movement with flying, walking, and swimming system used until mid 1600s

Linnaeus 18th century created binomial nomenclature

Charles Darwin in 19th century, theory of evolution/adaptation “the origin of species”

Question 7

phylogeny

Answer 7

the evolutionary development and history of a species or higher taxonomic grouping of organisms

OR

the taxonomic classification mirroring the evolutionary development

Question 8

cladistics

Answer 8

tries to show evolutionary relationships based on physical traits shared by different groups of organisms

Question 9

15.1 Viruses are Infectious Particles of Genetic Info + Protein

Answer 9

a. smaller and simpler than cells (12x smaller than bacterium)
- all viruses have genetic info + protein coat (capsid)
some may have an envelope

B. host range consists of the organism it infects
- can enter only a cell that has a specific receptor
all species get viral infections
reservoir of a virus is the site where it exists in nature

C. Are viruses alive>
- most do not consider them to be
- don’t metabolize, respond to stimuli, or reproduce on their own
- do have genetic material and mutate -> natural selection
- not part of taxonomic hierarchy, instead grouped by chemical similarities

Question 10

15.2 Viral replication occurs in 5 stages

Answer 10

1. attachment
2. penetration
3. synthesis
4. assembly
5. release

amount of time varies

Question 11

draw and label all 5 steps of viral replication within a cell

Answer 11

refer to figure 15.2 in notes/lect slides

Question 12

15.3 cell death may be immediate or delayed

Answer 12

A. some viruses kill cells immediately
- lytic infection/pathway
- virus enters cell + immediately replicates and lyses host
- “phage therapy” for bacterial infections - unlikely to acquire resistance, targeted to specific bacteria, studied by USSR
essentially viruses that selectively target bacteria

B. Viral DNA may also hide in a cell
- lysogenic infection/pathway
- genetic material of a virus is replicated along with the host cells chromosome
- prophage
- host not immediately destroyed
- can also switch to lytic pathway

Question 13

15.4 Effects of a Viral infection may be mild or severe

Answer 13

A. Symptoms may result from cell death + immune response
- incubation period = the time between exposure to disease agent and disease signs and or sympyoms
- influenza virus -> flu
- dead + damaged cells in airway cause the respiratory symptoms of influenza -> cough + sore throat
- fever + body aches caused by cytokines released by immune systems

B. some animal viruses linger for year
- latent infection does not produce disease symptoms
- viral genetic info inside cell
- herpes simplex virus type I
- cold sores on lips, stressed cells release viruses that infect other cells, cold sore localized death of these cells
- HIV
- retrovirus - uses reverse transcriptase
- RNA genome
- infects helper T cells
- loss of these cells leads to AIDS

• Human papillomavirus causes cervical cancer by signaling host cell to divide continuously

C. Drugs and Vaccines help fight viral infections
- some antiviral drugs interfere with enzymes or other proteins that are unique to viruses
few medicines inhibit viruses without killing infected host cells
complicated by genetic variability by viruses
vaccination teaches immune system to recognize virus
childhood vaccinations greatly reduced or eliminated viral infections
fertilized chicken eggs used to produce viruses

Question 14

epidemic, pandemic, and endemic

Answer 14

more cases of disease than expected

widespread, worldwide epidemic

disease outbreak that is consistently present

Question 15

HIV

Answer 15

human immunodeficiency virus

Question 16

AIDS

Answer 16

acquired immunodeficiency syndrome

Question 17

origin of HIV

Answer 17

raw bushmeat (monkeys), origin in SF LGBTQ+ community

Question 18

15.5 Viruses Cause Diseases in Plants

Answer 18

• first virus ever discovered was tobacco mosaic virus
• most spread by plant-eating insects
• spread through plasmodesmata
• can use post-transcriptional gene silencing to fight off infections

Question 19

Rabies

Answer 19

Rabies is a viral disease that causes acute inflammation of the brain in humans and other mammals
incubation period typically 1-3 months
infection via animal bites
- hydrophobia - difficulty swallowing
99.99+ % fatal (<6 human survival cases EVER, 4 in last 5 years)
Vaccine is very effective if given early enough
US human (fatal) cases 1-3/year

Question 20

Ebola

Answer 20

Originated in central africa - blood vessels break down, internal bleeding, extreme bleeding and ultimately death

Question 21

zika virus

Answer 21

mosquito-transmitted; (RNA)

associated with microcephaly (mechanism unknown)
- mild to significant learning disabilities
- impaired motor functions
- difficulty with movement and balance
- speech delays

first isolated in uganda in the zika forrest - 1947

brazil 2015 - 3.500 cases (47 fatal)

Question 22

15.6 Viroids and Prions are other noncellular infectious agents

Answer 22

A. A Viroid is an infectious RNA molecule
- naked RNA
- does not encode proteins
- interferes with ability to produce proteins

B. A prion is an infectious protein
- abnormal form causes brain cells to die
- spongiform encephalopathies
- mad cow disease (BSE)
- human forms
- kuru - cannibalism
- creutzfield-Jakob disease (CJD)
- fatal familial insomnia

Question 23

monkeypox + smallpox

Answer 23

within 1-3 days after appearance, patient develops rash, often beginning on the face then spreading

illness typically lasts 2-4 weeks

monkeypox disovered 1958 in africa, dna virus, mortality <10%

presents like chicken pox and mild smallpox

cross-immunity with smallpox

smallpox - 30% fatality, successful vaccine in 1797, completely eradicated in 1977, still exists in labs

Question 24

16.1 Prokaryotes are a biological success story

Answer 24

Prokaryote
- single celled organism that lacks a nucleus and membrane-bounded organelles
2 prokaryotic domains
- bacteria
- archaea

Question 25

16.2 prokaryote classification traditionally relies on visible features

Answer 25

A. Microscopes reveal cell structures
internal structure
- cell membrane, DNA, cytoplasm, ribosomes
- nucleoid
- plasmids
external structure
- cell wall
- peptidoglycan
- 3 common shapes
- coccus, bacillus, spirillium
- arrangements can also be important
external structures
- gram stain
- gram positive
- thick peptidoglycan layer
- gram negative
- thinner cell walls
- outer membrane

glycocalyx
- capsule or slime layer
pili
- attachment or DNA transfer
flagellum
- not the same as eukaryote

endospores (little particles that work like seeds, but are not seeds)
- dormant, thick-walled structures
- clostridium botulinum
- botulism
- bacillus anthracis
- anthrax

B.metabolic pathways may be useful in classification
autotrophs
- carbon from inorganic sources
heterotrophs
- carbon from organic sources
phototrophs
- derive energy from sun
chemotrophs
- oxidize inorganic or organic chemicals
photoautotroph
- plants and cyanobacteria, ALGAE
- sunlight for energy and CO2 for carbon
chemoheterotroph
- disease-causing bacteria use host as carbon and energy source

oxygen requirements
- obligate aerobe
-obligate anaerobe
-facultative anaerobe

C. molecular data reveal evolutionary relationships
- revolution in microbial taxonomy
- used rRNA sequences
- closer to taxonomy

Question 26

16.3 Prokaryotes transmit DNA vertically and horizontally

Answer 26

vertical gene transfer
- transmit DNA from generation to generation as they reproduce
- binary fission (asexual)

horizontal gene transfer
- transformation
- naked DNA
- transduction
- virus mediated
- conjugation
- sex pilus

Question 27

16.4 - START HERE AT SLIDE 19 AND FILL IN UNTIL CAUGHT UP !

Question 28

Cholera

Answer 28

water-borne

death from dehydration in as few as 12 hours

vibrio cholerae - gram negative rod; facultatively anaerobic

extremely severe diahrea

Question 29

global transportation

Answer 29

cholera - can spread worldwide rapidly with modern transportation

nepal haiti 2010 outbreak

Question 30

lous pastear ADD IN

Question 31

Joseph Lister 1827-1912

Answer 31

English Surgeon

applied pasteur’s discoveries beginning 1865

developed antiseptic surgical techniques - 5% carboxic acid

“Listerine” - 1879 marketing idea (not his)

Question 32

Robert Koch 1843-1910

Answer 32

determined that different species of bacteria cause different diseases

developed rigorous proofs (postulates) to determine which bacteria caused which disease

the bacteria must be present in every case of the disease
the bacteria must be isolated from the host with the disease grown in pure culture
the specific disease must be reproduced when a pure culture …… COMPLETE

Question 33

GO BACK AND LOOKOVER SLIDES AS NEEDED!

Question 34

16.5 INPUT HERE

Question 35

Good - Food and Medical Uses

Answer 35

acetobacter e al -> EtOH acetic acid

vinegar
sauerkraut
kimchee

biotech

genetic engineering

Question 36

revise and go back as needed!

Question 37

17.1 Protists Lie at the Crossroads between simple and complex organisms

Answer 37

A. What is a protist?
- eukaryote that did not fit the description of a plant, fungus, or animal
- based on new molecular data, the former Kingdom Protista has shattered into dozens of groups whose relationship ….. GO BACK AND FINISH !!

B: Protists are important in many ways
- very metabolically diverse
- ecosystem FINISH HERE FINISH UP !