12. Which of the following
processes would never
contribute to genetic
variation within a bacterial
population?
meiosis
13. During conjugation
between an Hfr cell and
an F- cell
Genes from the Hfr cell may replace
the genes of the F- cell by
recombination
14. Emerging viruses arrive by
All of the above
a)
b)
c)
Mutation of existing viruses
The spread of existing viruses to
new host species
Broader dissemination of an
existing virus within the current
host population
15. A certain mutation in E coli
makes the lac operator
unable to bind to the active
repressor. How would this
affect the cell?
The cell would wastefully produce the
enzymes for lactose metabolism
continuously, even in the absence of
lactose
18. Classify bacteria by habitat
1. halophile
2. coliform: your
digestive tract
3. thermophile
4. acidophile
19. Classify bacteria by metabolic pathway
1. obligate aerobe:
require O2
2. anaerobe: O2 kills
anaerobes
3. facultative aerobe: can
live with O2 and not
4. heterotroph v
photoautotroph
20. Classify bacteria by metabolic pathway
• M. tuber
1. obligate aerobe:
require O2
22. Classify bacteria by metabolic pathway
• E. coli (facultative)
1. obligate aerobe:
require O2
2. anaerobe: O2 kills
anaerobes
3. facultative aerobe: can
live with O2 and not
23. Classify bacteria by metabolic pathway
• cyanobacteria
(photoautotroph)
1. obligate aerobe:
require O2
2. anaerobe: O2 kills
anaerobes
3. facultative aerobe: can
live with O2 and not
4. heterotroph v
photoautotroph
24. capsule: sugar material that covers cell
wall
• Strep pyroxenes, H.
influenza
• protect against
phagocytosis
• protect against
desiccation
• allow adherence
25. fimbriae & pili: attachment purpose
structures
• pile: used for
conjugation (sexual
reproduction)
26. slime layer: sticky matrix of
polysaccharides that protects the
bacteria
• Streptococcus mutans
cause tooth decays
28. internal/genome structure of bacteria
• one chromosome (DNA)
• no organelles
• plasma membrane
carries out metabolic
processes
• Some bacteria have
additional genomes,
circular DNA, plasmids
56. Gram
• exotoxin
– made of G positive
– botulin and tetanin are
examples
– can elicit immune
response
– can be vaccinated
against
• endotoxin
– made of G-negative
– made of outer
membrane (OM)
– are released when
bacteria die
– does NOT elicit an
immune response
– you get more sick
– vaccination is difficult
62. Phylum: Forams
• shrimp
• Porous, multichambered calcium
carbonate shells called
tests
• Pseudopodia extend
through the pores
• ocean pH
environmental problem:
acidity dissolves tests
63. Forams (importance)
• layers of foram tests in
marine sediments from
limestone and oil deposits
– Egyptian pyramids
• act as carbon reservoir
• used by geologists to
locate oil reserves (oil
explorer)
• used to determine age of
rocks and pas climate
65. Kingdom: radiolarians
• have silica tests fused
into one piece (like
diatoms)
• pseudopodia are called
axopodia, which radiate
from central body
• only ONE clade
66. Kingdom: amoeba
• have lobe-shaped
pseudopodia (false feet)
rather than threadlike
• do not have tests and
have no shape
• The Blob (film)
67. Four Clades of Amoeba
1.
2.
3.
4.
Gymnanoebas
Entaamoeba
plasmodial slime mold
cellular slime mold
69. Entaamoeba
1.
2.
3.
4.
Gymnanoebas
Entaamoeba
plasmodial slime mold
cellular slime mold
• generally parasitic
– ex. Entaamoeba histolytica:
causes dysentery and
organ damage
– Naegleria: cause fatal
encephalitis
• found in warm fresh waters
in southern states
• infections occur via nose
and in summer months
• very rare: you’re more
likely to win the lottery
– E. histolyta in stool: cyst,
trophozoite
– N. fowleri in brain
70. plasmodial slime mold
1.
2.
3.
4.
Gymnanoebas
Entaamoeba
plasmodial slime mold
cellular slime mold
• spend most life cycle as a
unicellular plasmodium
• made up of thousands of cells
that fuse to ONE giant cell
with many nuclei
• When stressed, plasmodium
develop to sporangia and
produce spores.
• Spores germinate into
biflagellated cells, which act as
gametes or as amoeboid cells.
• Syngamy of gametes produce
new plasmodium.
72. cellular slime mold
1.
2.
3.
4.
Gymnanoebas
Entaamoeba
plasmodial slime mold
cellular slime mold
• cells do NOT fuse; but
they act as one organism
• spends most life cycle as
feeding individual protist
cells
• form pseudopodia (slug)
when food is depleted
• slug develops to fruiting
body to produce spores
73. cellular slime mold
• life cycle
– fruiting bodies
– amoebas
– signal: cells aggregate
and form plasmodium
slime mold; they do NOT
fuse
– they move as one
74. kingdom: Rhodophyta (red algae)
• phycoerythrin (red
pigment) which allowed
Rhodophyta to live in
deeper waters
• Most are large and
multi-cellular
• store sugar as floridean
starch (glycogen) like
humans
• found in tropical waters
75. kingdom: Rhodophyta (red algae)
• Uses
– eaten as food
– agar: food, petri dish
– coralline algae secrete
shells of calcium
carbonate, which form
coral reefs. Algae are
NOT coral. They are part
of the ecosystem that
supports corals.
76. kingdom: chlorophyta (green algae)
1. chlorophylls
2. charophyceans
• have chloroplasts
– chlorophyll a and b
– store sugar in the form
of starch
– have accessory pigments
and stacked thylakoids
– ex. Volva
– ulva (sea lettuce)
– calberna (sea feather)
A virus containing RNA as its genetic material. The RNA may be single stranded or double stranded. Examples of RNA viruses include Reoviruses, Picornaviruses, Togaviruses, Orthomyxoviruses, Rhabdoviruses, etc.
R plasmids can contain genes that confer resistance to antibiotics such as ampicillin.When antibiotics are used, they only kill those bacteria without resistance to that antibiotic. This causes resistant bacteria populations to increase. This is the reason that we see more and more antibiotic resistant strains of bacteria.Many R-factors can pass from one bacterium to another through bacterial conjugation and are a common means by which antibiotic resistance spreads between bacterial species, genera, and even families. For example RP1, a plasmid that encodes resistance to ampicillin, tetracycline, and kanamycin originated in a species of Pseudomonas, from the Family Pseudomonadaceae, but can also be maintained in bacteria belonging to the family Enterobacteriaceae, such as Escherichia coli.
corepressor:any substance that reacts with a genetic repressor in order to activate it and decrease gene expressionAPPEARS IN THIS RELATED CONCEPT:Operonscorepressor:any substance that reacts with a genetic repressor in order to activate it and decrease gene expressionAPPEARS IN THIS RELATED CONCEPT:Operons
An operon can be repressible or induciblelac operonThe lac operon is an operon required for the transport and metabolism of lactose in Escherichia coli and other enteric bacteria. It consists of three adjacent structural genes, lacZ, lacY and lacA. The lac operon is regulated by several factors including the availability of glucose and of lactose.inducera molecule that starts gene expressioninducible operonIn negative inducible operons, a regulatory repressor protein is normally bound to the operator, which prevents the transcription of the genes on the operon. If an inducer molecule is present, it binds to the repressor and changes its conformation so that it is unable to bind to the operator. This allows for expression of the operon.
reverse transcriptase, also called RNA-directed DNA polymerase, an enzyme encoded from the genetic material of retroviruses that catalyzes the transcription of retrovirusRNA (ribonucleic acid) into DNA
Hfr cell: A high-frequency recombination cell (Hfr cell) (also called an Hfr strain) is a bacterium with a conjugativeplasmid (often the F-factor) integrated into its genomic DNA.The Fertility factor (first named F by one of its discoverers Esther Lederberg) allows genes to be transferred from one bacterium carrying the factor to another bacterium lacking the factor by conjugation. The The episome that harbors the F factor can exist as an independent plasmid or integrate into the bacterial cell's genome. There are several names for the possible states:Hfr bacteria possess the entire F episome integrated into the bacterial genome.F+ bacteria possess F factor as a plasmid independent of the bacterial genome. The F plasmid contains only F factor DNA and no DNA from the bacterial genome.F' (F-prime) bacteria is formed by incorrect excision from the chromosome, resulting in an F plasmid carrying bacterial sequences that were next to where the F episome was inserted.F- bacteria do not contain F factor. Will act as the recipient.
Operon - a cluster of structural genes that are expressed as a group and their associated promoter and operator How does the system work? Without lactose in the cell, the repressor protein binds to the operator and prevents the read through of RNA polymerase into the three structural genes. With lactose in the cell, lactose binds to the repressor. This causes a structural change in the repressor and it loses its affinity for the operator. Thus RNA polymerase can then bind to the promoter and transcribe the structural genes. In this system lactose acts as an effector molecule. lac Operon - an inducible system