Lesson 9: Bacteria & Viruses

Halophile

"Salt-loving" archaea that live in environments that have very high salt concentrations

Bacteriophage

A virus that infects bacteria is called a?

Liposaccharide layer & Extra Phospholipid Bilayer

2 major components of the Gram-negative bacteria that the Gram-positive bacteria does not have are?

D) Reverse Transcriptase, Integrase, Protease

A Retrovirus contains what three special proteins? A) RNA Replicase, Integrase, Protease B) Reverse Transcriptase, Nuclear Permease, Protease C) RNA Replicase, Nuclear Permease, Protease D) Reverse Transcriptase, Integrase, Protease

Virion

A fully formed virus that is able to establish an infection in a host cell

(B) 3, 5 A gram-positive bacteria has 3 layers while a gram-negative bacteria has 5 layers.

A gram-positive bacteria has ___ layers while a gram-negative bacteria has ___ layers. (A) 2, 3(B) 3, 5(C) 5, 3(D) 3, 2

Methanogens

A group of archaebacteria that produce methane as a by product of their metabolism.

B) Prion Because they are made of proteins and contain no genetic material

A hybridization probe is a fragment of genetic material that is used to to detect the presence of nucleotide sequences that are complementary to the sequence of the probe. Which infectious agent could not be detected with a probe? A) Retrovirus B) Prion C) Double-stranded RNA material D) Single-stranded DNA material

Extremophile

A microorganism, especially an archaean, that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration.

Negative Gram stain

A pink gram stain is considered to be a?

Gram Staining

A process by which components of bacterial cell walls are bound to Gram's stain. Depending on the amount of peptidoglycan in their cell walls, bacteria stain differently and are classified as Gram-negative or Gram-positive.

Positive Gram stain

A purple gram stain is considered to be a?

A) The specimen contains DNA and RNA Can ONLY contain one at a time

A scientist is investigating a specimen in a laboratory. She is attempting to determine whether it is a virus or not. Which of the following would allow her to conclude that it is not a virus? A) The specimen contains DNA and RNA B) The specimen is extremely small C) The specimen has a protein coat D) The specimen has no organelles

Thermophile

A type of extremophile—that thrives at relatively high temperatures, between 41 and 122 °C. Many are archaea

Lytic Cycle

A viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses

Lysogenic Cycle

A viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA

(B) Lipoteichoic Acid Lipoteichoic Acid is in Gram-Positive Cell Walls and can activate the Human Immune System.

Along with Peptidoglycan, what other molecule will be in Gram-Positive Cell walls? (Hint: This molecule can actually activate the human immune system) (A) Arachidonic Acid(B) Lipoteichoic Acid(C) Prostaglandins(D) MHC Class III antigens

Catalytic RNA

An RNA segment that has the ability to self-replicate and synthesize proteins without additional enzymes

Retrovirus

An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.

D)It would prevent the virus from attaching to the host cell Endocytosis is how the virus infects the animal cell in the first place. The drug aims to prevent infection from occurring, so it would not facilitate this process. The drug affects the membrane of the cell, and does not interfere with the capsid structure. Since the virus depends on specific receptors on the host cell to attach, this process would be prevented when these specific receptors are modified by the antiviral drug.

An antiviral drug specifically modifies viral receptors on a eukaryotic host cell. How might this affect the viral reproductive cycle? A)It would facilitate the process of viral endocytosis B)It would result in the degeneration of the viral capsid C)It would enhance the process of viral apoptosis D)It would prevent the virus from attaching to the host cell

Reverse Transcriptase

An enzyme encoded by some certain viruses (retroviruses) that uses RNA as a template for DNA synthesis.

Braun's Lipoproteins

Attaches outer membrane (cell envelope) to peptidoglycan layer of Gram-negative cell wall

(C) Anaerobic and Aerobic Bacteria can be classified into Anaerobic or Aerobic, based on if they require Oxygen for their metabolism.

Bacteria can also be classified into two major groups based on the environmental conditions they need for their metabolism. What are these classifications? (A) Ahydrogenic and Hydrogenic(B) Asulfuric and Sulfuric(C) Anaerobic and Aerobic(D) Anitrogenic and Nitrogenic

False

Bacteria have membrane-bound organelles. (True/False)

Chemotaxis

Cell movement that occurs in response to chemical stimulus

A) A lytic virus, because it would cause a rapid destruction of the articular capsule

Certain types of arthritis, or inflammation of the joints, could be caused by viruses. In some cases, infected individuals experience an acute, rapid degradation of the chondrocytes that make up the articular capsule upon infection. Which type of virus is likely to cause such acute symptoms? A) A lytic virus, because it would cause a rapid destruction of the articular capsule B) A lysogenic virus, because its virulence tends to be expressed immediately C) A lytic virus, because it has a brief latent phase and immediately attacks the joints D) A lysogenic virus, because it would specifically target and quickly destroy the chondrocytes

Aerotolerant Anaerobes will never use Oxygen in their metabolism, but are not hurt by having Oxygen in the environment. Obligate Anaerobes cannot survive in Oxygenated environments, let alone incorporate Oxygen into their metabolism.

Compare Aerotolerant Anaerobes and Obligate Anaerobes.

Obligate Aerobes absolutely require oxygen for their metabolism to function normally. Facultative Anaerobes will use Oxygen if it is present, but can switch to an anaerobic metabolism if there is no oxygen.

Compare Obligate Aerobes and Facultative Anaerobes.

(+)-Sense RNA viruses have their genome directly translated to functional proteins by the host's Ribosomes, like the cell's mRNA. (-)-Sense RNA Viruses need to have their genomes replicated by an RNA Replicase before they can be translated.

Compare Positive Sense and Negative Sense RNA Viruses, focusing on how they have their genomes transcribed.

Fimbriae/Pili are little hairs on the outside of some bacteria. Flagella is the tail of a Bacteria that allows it to move.

Compare fimbrae/pili with flagella.

The Cell Wall of a gram-positive bacteria is much thicker than that of a gram-negative bacteria.

Compare the Cell Wall of a gram-positive bacteria to that of a gram-negative bacteria.

In a Lytic Cycle, the virus uses the cell's machinery with no regard for the cell, ending with the host cell lysing.In a Lysogenic Cycle, the virus integrates itself into the host genome, and can remain dormant until environmental factors make this virus return to a Lytic Cycle.

Compare the Lytic and Lysogenic Cycles of Viral Replication.

Thermophiles love heat and extreme temperatures. Halophiles love salty environments. Methanogens produce methane gas ("swamp gas").

Compare the three types of "extremophiles": (1) Thermophiles(2) Halophiles(3) Methanogens

Transformation occurs when a recipient cell takes up extracellular DNA. Transduction occurs when a virus transfers genetic material from one bacteria to another. Conjugation occurs when one bacteria directly transmits a plasmid or other DNA to another bacteria.

Compare transformation, transduction, and conjugation

Circular Double-Stranded DNA

In E Coli, the genetic material is composed of ___.

Inclusion Body

In a bacterium, stored nutrients for later use.

(1) The Retrovirus enters the cell via either Receptor-Mediated Endocytosis or Direct Fusion. (2) The Retrovirus goes through the uncoating of its capsid. (3) Reverse Transcriptase produces a double-stranded piece of cDNA using the ssRNA of the Retrovirus as a template. (4) Integrase clips off the 3' ends of the cDNA and then integrates it into the host's DNA in the Chromosome. (5) The host will then actively transcribe this DNA into RNA. (6) The RNA will be translated into viral proteins, which will then self-assemble into immature viruses. (7) Immature virus will bud off (exocytosis), gaining an envelope. (8) Immature viruses mature as protease cleaves the other proteins, Reverse Transcriptase and Integrase, activating them.

Describe the process by which a Retrovirus enters the host cell and reproduces more viruses. Be sure to include the role of Reverse Transcriptase, Integrase, and Protease.

Picture

Draw out a Bacterial Growth Curve, labeling the following:- Death Phase- Exponential Phase- Lag Phase- Stationary Phase

Protease

Enzyme that breaks down proteins into its smaller counterparts

Chemotaxis is the ability of a bacteria to move in the direction of a certain chemical.

Flagella allow for Chemotaxis. What is that?

Prions

Infectious protein particles that do not have a genome. NO DNA/RNA, only made of proteins

(B) Nucleoid Region The Nucleoid Region is where the DNA is concentrated in Prokaryotes.

Instead of having a Nucleus, what is the name of where the DNA is concentrated in Prokaryotes? (A) Nucleolus(B) Nucleoid Region(C) Transcriptional Region(D) Nucleic Acid Pool

(B) Some bacteria produce necessary compounds for humans, like Vitamins E and Biotin (B7). Bacteria actually produce Vitamin K and B7 for humans in the human gut.

It is well-known that Bacteria and the human body have a complex relationship. Which of the following statements about their relationship is FALSE? (A) Bacteria cells outnumber the human body cells by a factor of 10.(B) Some bacteria produce necessary compounds for humans, like Vitamins E and Biotin (B7).(C) Some bacteria are Mutualistic Symbiotes, meaning both the bacteria and humans benefit from interacting.(D) Some pathogenic bacteria can live extracellularly or intracellularly.

(B) II < III < II < IV < I The following are the layers of a bacteria from inside to outside: Plasma Membrane < Cell Wall < Plasma Membrane < Lipopolysaccharide (LPS) Layer < Slime Layer/Capsule.

List the following layers of a gram-negative bacteria from inside to outside: I. Slime Layer/CapsuleII. Plasma MembraneIII. Cell WallIV. Lipopolysaccharide (LPS) Layer (A) I < II < III < IV < III(B) II < III < II < IV < I(C) I < IV < II < IV < II(D) III < IV < III < II < I

(D) II < III < I The following are the layers of a bacteria from inside to outside: Plasma Membrane < Cell Wall < Slime Layer/Capsule.

List the following layers of a gram-positive bacteria from inside to outside: I. Slime Layer/CapsuleII. Plasma MembraneIII. Cell Wall (A) I < II < III(B) II < I < III(C) III < II < I(D) II < III < I

C) Archaea There is very little oxygen to be found at hydrothermal vents, which are found on the ocean floor. Organisms that can survive at temperatures above 106F are known as thermophiles, which means heat-loving. Archaea are the most common extremophiles (organisms capable of surviving in extreme environments such as increased heat or lack of oxygen), and Methanopyrus kandleri belongs to this domain.

Methanopyrus kandleri is an organism which lives in a hydrogen-carbon dioxide environment, and was first discovered in a hydrothermal vent where temperatures reached 230°F. What sort of organism is this? A) Protist B) Cyanobacteria C) Archaea D) Bacteria

A) Purple spheres

Methicillin-resistant Staphylococcus aureus (MRSA) is an antibiotic-resistant "superbug" that can cause deadly infections in humans. What would these Gram-positive bacteria look like under a microscope? A) Purple spheres B) Clear Rods C) Pink Rods D) Purple spirals

D) Lysogenic viruses All lytic viruses destroy the cell while lysogenic viruses may be replicated with the cell. Thus the host will generate new daughter cells infected with the virus, eventually leading to a neoplasm, also known as tumor.

Oncoviruses are a type of animal virus that can cause a neoplasm - an abnormal, often excessive, growth of tissue. Which type of virus is likely to be an oncovirus? A) Bacteriophage B) Lytic C) Enveloped D) Lysogenic viruses

Hydrostatic Pressure

One of the main functions of the cell wall section of the cell envelope is its ability to withstand?

Capsid

Outer protein coat of a virus

Slime Layers are loosely associated and can be washed off, whereas Capsules have defined boundaries and cannot be washed off.

The outer layer of a Bacteria may be a Capsule or a Slime Layer. What is the difference between these two?

Beta 1-4

The peptidoglycan consists of two amino sugars connected by ____ glycosidic linkages

Conjugation

The temporary union of two bacteria or unicellular organisms for the exchange of genetic material. Useful for antibiotic resistance

Sugar & Amino acids (Polypeptide)

Peptidoglycan is made up of ____ & ____ that form a mesh like structure

(D) All of the above are Virulence Factors.

Plasmids can oftentimes contain Virulence Factors, which are traits that will make the Prokaryote more Pathogenic. Which of the following is NOT a Virulent Factor? (A) A gene coding for Projections that help the bacteria attach to cells.(B) A trait enabling the Prokaryote to evade the host's immune system.(C) A trait that increases toxin production.(D) All of the above are Virulence Factors.

C)Obligate anaerobe

Porphyromonas gingivalis is a Gram-negative bacterium, found in the oral cavity, is negatively affected by the presence of oxygen. What term best describes this bacteria? A)Facultative anaerobe B)Aerotolerant anaerobe C)Obligate anaerobe D)Obligate aerobe

Direct fusion

The viral envelope fuses with the cell membrane and the intact nucleocapsid goes into host cell

(B) II < III < I In order from smallest to largest: Virus (100x smaller than bacteria) < Prokaryotic Cell (several times smaller than Eukaryotic Cell) < Eukaryotic Cell

Put the following in order from smallest to largest: I. Eukaryotic CellII. VirusIII. Prokaryotic Cell (A) I < II < III(B) II < III < I(C) III < II < I(D) II < I < III

D)It could add to the virulence and transmission of the virus

Reverse transcriptase is known for having poor proofreading activity. What would be a consequence of this? A)It makes each new viral generation more viable B)It establishes lifelong infection in the host C)It could cause the host cell to incorrectly proofread as well D)It could add to the virulence and transmission of the virus

Bacilli

Rod Shaped Bacteria is called?

The lac operon that controls lactose digestion in prokaryotes normally operates at a very low basal level, and is upregulated by the presence of its substrate. Lactose is a dimer of galactose and glucose. The absence of glucose leads to an increase in cAMP, because now the cell must rely much more heavily on the lac operon for energy. This sets off a cascade of events that upregulate the enzymes that cleaves lactose. The presence of lactose and absence of glucose will lead to the most galactose and thus will dye the most strongly blue

Scientists have developed a dye for galactose, which turns darker shades of blue as the concentration of this monosaccharide increases (dose dependent). In an experiment using bacteria that can metabolize both lactose and glucose, researchers set up test tubes as shown in Table 1. A plus sign indicates a sugar was added to the test tube, and a minus sign indicates the sugar is absent. Assuming bacterial concentrations stay constant, which test tube will show the strongest blue color? Test Tube A: Lactose +, Glucose + Test Tube B: Lactose +, Glucose - Test Tube C: Lactose -, Glucose + Test Tube D: Lactose -, Glucose - A) A B) B C) C D) D

Viroids *Recently found in humans with Hepatitis D

Small circular RNA molecules that infect plants and disrupt their growth. Considered to be catalytic RNA

Cocci

Spherical Shaped Bacteria is called?

Spirilla

Spiral Shaped Bacteria is called?

Viriods are small pieces of circular RNA that can self cleave to create more of themselves. Prions are small misfolded proteins that can cause normal proteins to misfold (α-helices will become β-sheets).

Subviral Particles and Viruses are together termed "nonliving infectious agents." Compare the two main types of Subviral Particles: Viriods and Prions.

Peptidoglycan

The cell wall of bacteria is made of a substance called ____.

Integrase

The enzyme responsible for integrating viral DNA into the host cell's DNA

Receptor mediated endocytosis

The movement of specific molecules (viruses) into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.

Viral latency

____ is the ability of a pathogenic virus to lie dormant within a cell, denoted as the lysogenic part of the viral life cycle

True. Because there are no Mitochondria in Prokaryotes, their plasma membrane is used for the Electron Transport Chain and ATP synthesis.

True or false? Because there are no Mitochondria in Prokaryotes, their plasma membrane is used for the Electron Transport Chain and ATP synthesis.

True. Plasmid DNA is not necessary for the survival of the bacteria, so it is not considered part of the bacteria's genome.

True or false? Plasmid DNA is not necessary for the survival of the bacteria, so it is not considered part of the bacteria's genome.

False. Protozoa are single-celled organisms that share many characteristics with animals, but are considered protists.

True or false? Protozoa are single-celled organisms that share many characteristics with animals, and are considered animals.

False. The Negative Sense RNA Viruses must use an RNA Replicase that the virus itself carries.

True or false? The Negative Sense RNA Viruses can use an RNA Replicase enzyme from its host.

Provirus

Viral DNA that has attached to a host cell's chromosome and that is replicated with the chromosome's DNA

Viriods are small pieces of circular RNA that can self cleave to create more of themselves. Virions are mature viruses that are complete with a capsid. They have not entered a host and undergone uncoating yet.

Viriods and Virions are commonly mixed up. What's the difference between these two things?

Subviral Particles

Viroids & Prions are classified as?

Obligate intracellular parasites

Viruses are ______, which means they can replicate only within a host cell.

Nonliving Infectious Agents

Viruses are classified as?

Cocci, Bacilli, & Spirilla

What are the 3 basic shapes of bacteria?

Nucleic Acid & Capsid *Some will have an envelope

What are two structural components that a virus contains?

(C) Peptidoglycan

What compound is the Cell Wall of a bacteria composed of? (A) Lipopolysaccharides(B) Glycolipids(C) Peptidoglycan(D) Lipopeptides

A) Absence of genetic material

What distinguishes prions from viruses? A) Absence of genetic material B) Ability to cause infection C) Type of protein arrangement D) Presence of an envelope

Normal protein: Alpha Helix Prion: Beta Sheet

What is the conformation of a normal protein vs. prions?

Inclusion Bodies store things such as nutrients. Plasmids contain extra DNA that may provide a protection to the bacteria.

What is the function of Inclusion Bodies versus Plasmids?

A Nucleoid is a circular double-stranded piece of DNA that is free-floating in the cytoplasm.

What is the structure of a Nucleoid? How does it compare to the Eukaryotic Nucleus?

A Prokaryote ("before nuclues") doesn't have a nucleus while a Eukaryote does.

What makes something a Prokaryote versus a Eukaryote?

(C) Lipopolysaccharide Layer Gram-negative bacteria have a special Lipopolysaccharide (LPS) Layer.

What special layer does a gram-negative bacteria have that a gram-positive bacteria does not? (A) Slime Layer/Capsule(B) Plasma Membrane(C) Lipopolysaccharide Layer(D) Cell Wall

C) Two F+ bacteria with identical plasmid but not chromosomal DNA The F+/F- determination reflects the presence / absence of the plasmid that codes for the pilus. Conjugation is a method of genetic recombination employed by bacteria to help transfer genes that can confer some sort of advantage, like antibiotic resistance. This means that there is a selective advantage to the original cell retaining the advantageous DNA. The pilus transfers a copy of the plasmid that coded it to a pre-existing cell, creating two F+ positive cells with identical plasmid, but not chromosomal DNA.

What type(s) of cells do you obtain after a F+ bacterium conjugates with a F- bacterium? A) One new F- bacterium which transferred the plasmid to the other cell, which is now F+ B) Two F+ bacteria with identical plasmid and chromosomal DNA C) Two F+ bacteria with identical plasmid but not chromosomal DNA D) Two bacteria with identical plasmid and chromosomal DNA, but one is F+, and the other F-

C) Plasma Membrane Bacteria, like eukaryotes, rely on a concentration gradient to drive an ATP synthase molecule. Bacteria are prokaryotes, and do not have membrane-bound organelles. Energy production in bacteria takes place across the plasma membrane, with the gradient between the extra- and intracellular environment providing the appropriate concentration gradient.

Where does energy production take place in bacteria that can perform aerobic metabolism? A) Mitochondria B) Inclusion Bodies C) Plasma Membrane D) Nucleus

C) DNA makes RNA that makes protein

Which central dogma of genetics had to be revisited after the discovery of a retrovirus? A) RNA replication cannot occur prior to translation B) Transcriptase assists in the formation of proteins C) DNA makes RNA that makes protein D) Messenger RNA does not always code for proteins

A) Some of the capsomers Antigenicity refers to the part of the virus that stimulates white blood cells. Internal proteins are not in direct contact with white blood cells, and therefore would not express antigenicity of any kind. The whole capsid is not entirely recognized by white blood cells. The capsomers are recognized by white blood cells, and therefore determine the virus antigenicity.

Which factor may help determine the antigenicity of a virus? A) Some of the capsomers B) The size of the virus C) The whole capsid D) The internal proteins

Transduction

____ is the process by which foreign DNA is introduced into a cell by a virus or viral vector

(B) II and III Only The following are considered Prokaryotes: II. Archaea III. Bacteria Protista are Eukaryotes.

Which of the following are considered Prokaryotes? I. Protista II. Archaea III. Bacteria (A) I and II Only (B) II and III Only (C) I and III Only (D) I, II, and III

(B) I and III only Each of the following are Antibiotic Targets that can discriminate between Bacteria and Eukaryotes:I. Ribosomes, because Bacteria have much smaller subunits.III. Flagella, because the biochemical makeups of Bacterial and Eukaryotic Flagella are significantly different.

Which of the following are possible targets of antibiotics that can discriminate between Bacteria and Eukaryotes? I. Ribosomes, because Bacteria have much smaller subunits.II. Plasma Membranes, because Eukaryotes incorporate no trans-fatty acids naturally.III. Flagella, because the biochemical makeups of Bacterial and Eukaryotic Flagella are significantly different. (A) I only(B) I and III only(C) II and III only(D) I, II and III

(D) I, II, and III The following are structures that are unique to Prokaryotes and are not held in common with Eukaryotes:I. NucleoidII. PlasmidIII. Inclusion Bodies

Which of the following are structures that are unique to Prokaryotes and are not held in common with Eukaryotes? I. NucleoidII. PlasmidIII. Inclusion Bodies (A) I Only(B) I and II Only(C) II and III Only(D) I, II, and III

(A) Enveloped, has ssRNA A Retrovirus is enveloped and has ssRNA.

Which of the following best characterizes a Retrovirus?(A) Enveloped, has ssRNA (B) Nonenveloped, has dsRNA(C) Enveloped, has ssDNA(D) Nonenveloped, has dsDNA

(C) I and III only Obligate Aerobes and Facultative Anaerobes can use Oxygen in their Metabolic Reactions.

Which of the following can use Oxygen for their metabolism? I. Obligate AerobesII. Aerotolerant AnaerobesIII. Facultative Anaerobes (A) I only(B) I and II only(C) I and III only(D) I, II and III

(C) Cell Wall The Cell Wall is what differentiates gram-positive and gram-negative bacteria

Which of the following characteristics of a bacteria are different between gram-positive and gram-negative bacteria? (A) Slime Layer(B) Plasma Membrane(C) Cell Wall(D) Cilia

C) Nucleolus A nucleolus, while not a membrane-bound organelle itself, is a region within a nucleus responsible for ribosome production. It is only found in eukaryotic cells.

Which of the following is NOT found in both prokaryotes and eukaryotes? A) Ribosomes B) Cytoskeleton C) Nucleolus D) Double-stranded DNA

(C) Both contain multiple chromosomes with DNA. Archaea actually have a singular, circular chromosome.

Which of the following is NOT one of the similarities between Archaea and Eukaryotes? (A) They both start translation with the amino acid Methionine.(B) They both have Histone-associated DNA.(C) Both contain multiple chromosomes with DNA.(D) They both use similar RNA Polymerases.

B) Flagella Cilia and pseudopodia are unique to protists and eukaryotes, and are not found in bacteria. Pili are primarily used to transfer DNA between bacteria during conjugation, but do have a small amount of motile function. Flagella are whip-like cellular appendages that are most responsible for prokaryotic cell motility.

Which of the following is most responsible for bacterial cell motility? A) Cilia B) Flagella C) Pili D) Pseudopodia

(D) I, II and III

Which of the following statements about Conjugation are true? I. Conjugation is a one-direction flow of information, from a donor Male to a recipient Female. II. Cells with the F+ Fertility Factor are the only ones able to transfer DNA to other cells. III. Cells that have the F+ can quickly spread Virulence Factors throughout a colony, and are known as HFR cells (High Frequency of Recombination Cells). (A) I only(B) II only(C) I and III only(D) I, II and III

D) Gram-negative bacteria are more likely to cause systemic effects because their outer membrane protects them from several antibiotics, making treatment more difficult. Gram-negative bacteria are considered to be more dangerous, because components of the outer membrane make them more resistant to antibiotics and the host's immune system. Additionally, the lipopolysaccharide found in its outer membrane is an endotoxin that damages the host.

Which of the following statements about the systemic effect of bacterial cells are true? A) Gram-negative bacteria are more likely to cause systemic effects because their lack of an outer membrane means they can more quickly infect host cells. B) Gram-positive bacteria are more likely to cause systemic effects because the lipopolysaccharide (LPS) in their membranes can act as a toxin to the circulatory system. C) Gram-positive bacteria are more likely to cause system effects because the peptidoglycan in their cell walls is tough and hard for medicine to penetrate. D) Gram-negative bacteria are more likely to cause systemic effects because their outer membrane protects them from several antibiotics, making treatment more difficult.

B) Archaea *Remember that term archaic means old

Which one is considered to be the oldest? A) Protista B) Archaea C) Bacteria

(D) Conjugation Conjugation uses a Sex Pilus to transfer the genetic material directly.

Which process requires the use of a Sex Pilus? What is that? (A) Transformation (B) Transduction (C) Recombination (D) Conjugation

E) All of the above *Only one at a time

Which type of nucleic acid can a virus be? A) Double-stranded DNA B) Double-stranded RNA C) Single-stranded DNA D) Single-stranded RNA E) All of the above

Viruses cannot survive without a host ("obligate"), they need to enter the host ("intracellular"), and they use the hosts machinary without benefiting the host and often times harming the host ("parasite").

Why are Viruses known as "obligate intracellular parasites"?

Gram stain is a purple stain. It sticks to the Cell Wall Layer composed of Peptidoglycan. Because gram-negative bacteria have so little peptidoglycan, this stain will essentially not stick but wash right off, giving it a pink appearance. Gram-positive bacteria will hold onto the gram stain, making them purple.

Why are gram-positive bacteria purple and gram-negative bacteria pink?

B) Bacteria & Archaea, Protista

_______ are considered to be prokaryotes, while ____ is an Eukaryote. A) Protista & Archaea, Bacteria B) Bacteria & Archaea, Protista C) Protista & Bacteria, Archaea

Transformation

is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s)