BIO II Exam 1 Chapters 20-23 (Phylogeny, Virus, Prokaryote, and Protist)

Euglenozoa

Among the earliest eukaryotes to possess mitochondria 1/3rd have chloroplasts and are autotrophic May become heterotrophic in the dark Others lack chloroplasts and are heterotrophic All have a flexible pellicle No sexual reproduction

Brown algae

Conspicuous seaweeds of northern regions Life cycle involves alternation of generations Sporophyte - multicellular and diploid Gametophyte - multicellular and haploid Not plants but protists.

Diatoms

Photosynthetic, unicellular organisms Unique double shells made of silica

Dinoflagellates

Photosynthetic, unicellular with flagella Live in aquatic environments Some are luminescent Do not appear to be directly related to any other phylum Major Cause of "Red tide" which are "blooms" that kill - fish, birds, and marine mammals may die from toxins

Protistan nutrition

Phototrophs, Heterotrophs and Mixotrophs. Phagotropic Ingest particle food Osmotrophic, Ingest soluble food

Apicomplexans

Spore-forming animal parasites Apical complex is a unique arrangement of organelles at one end of the cell which enables the cell to invade its host. Plasmodium causes malaria. Symptoms include chills and fever usually in late afternoon. Complex life cycle - sexual, asexual, different hosts. Eradication focused on eliminating mosquito vector, drug development, vaccines.

The host cells have the correct surface receptor that the virus can fit into.

Why do viruses only infect specific types of cells? Viruses infect the first cells they encounter. If a host cell is weakened, viruses have an easier time infecting it. The host cells have the correct surface receptor that the virus can fit into. Viruses only attack epithelial cells, such as the cells lining the lungs. The initial choice is random but once a cell type is chosen it becomes the preferred host.

Derived character.

a characteristic used in taxonomic analysis representing a departure from the primitive (ancestor) form; in cladistics, characteristics between the branch points of a cladogram that are shared by all organisms above the branch point and are not present in any below it Understand the difference between derived and ancestral characteristics.

Facultative aerobes

can use oxygen or not

HIV

each HIV particle has a glycoprotein on its surface, called gp120, that fits a cell-surface marker protein called CD4 on the surfaces of the immune system cells called macrophages and T cells; this virus is closely related a chimpanzee virus

Viral reproduction

entry into host because portions of capsid adhere to specific receptor on host Cell's outer surface...viral nucleic acid enter hose cell and codes for protein units inside capsid...takes over metabolic machinery of host cell Consider: Reproduction occurs through the following stages: attachment, penetration, biosynthesis (assembly), maturation, and release.

Rhizobium

example of a diazotrophs (nitrogen fixing bacteria)...only organisms (bacteria group) capable of taking gaseous nitrogen and combining it with hydrogen to make ammonia

Taxonomy.

field of biology concerned with classifying organisms and viruses; accepted pattern is Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (do kings play chess on fine green sand) Consider: Each taxa, as the hierarchical order descends, has a smaller number of species. So Order, Family, and Genus would have fewer species than Class.

Choanoflagellates

filter bacterial food from the water through the collars on the cells; structure similar to one on sponges Propulsion by a single posterior flagellum Consider: Choanoflagellates are the group of protists with similarities to sponges and other animals, including humans.d

E. coli

found in the lower intestine of warm blooded animals; 5000 genes, help host by producing vitamin K2 Consider: TB, cavities and several STDs caused by bacteria.

Transformation

genetic alteration of a cell's genome by the introduction of foreign DNA

Protistan cysts

may arise from sexual or asexual reproduction; facilitate spread of pathogens from one host to another and consumption can lead to human health problems

Cancer

may be caused by viruses through triggering the expression of cancer-causing genes present in the genome

Prion

misshapen protein agents with no associated nucleic acid that may convert other proteins in the cell to also become these agents causes Mad-cow disease and other related diseases

Amoebae

move by pseudopodia extension

Reproductive isolation

not being able to mate outside one's group

Protista

polyphyletic paraphyletic group or organisms that do not fit within Animalia, Plantae, or Fungi

Gram-positive Vs gram-negative

positive bacteria have a thicker peptidoglycan wall with small amounts of teichoic and lipoteichoic acid and will stain a purple color... gram-negative contain lipopolysaccharides, less peptidoglycan and no acids and do not retain the purple-colored dye; differences in cell's wall determines outcome of the Gram stain lipopolysaccharides in the outer membrane of certain bacteria make them more resistant to penicillin

Envelope

possessed by some viruses; are a lipid membrane (derived from a host-cell membrane) that is rich in lipoproteins and glycoproteins (generally virally encoded) surrounding virus capsid a layer of lipoprotein and glycoprotein that covers the outer surface of some viruses made from host

Principle of parsimony

principle state that scientists should favor the hypothesis that requires the fewest assumptions; simplest phylogenetic tree should be chosen

Protistan structures found on various members

pseudopodia (amoeboids) - movement and feeding cyst - protective outer covering on dormant cell flagella (zooflagellates) - propel the organism, collect food, and propel reproductive cells cilia (ciliates) - propulsion and feeding

Binary fission

reproductive process that produces identical cells by simple splitting

Obligate aerobes

requires oxygen

Foraminiferans

resemble tiny snails; have shells called tests composed of organic materials reinforced with grains of inorganic matter; their tests help make up many limestone deposits including the White Cliffs of Dover

Protistan mechanisms

slimy or hard protective coverings, toxins, sharp projectiles, bioluminescence, and/or spines

Convergent evolution

the independent development of similar structures in organisms that are not directly related; often found in organisms living in similar environments

Systematics

the reconstruction and study of evolutionary relationships (phylogenies)

Induction

the switch from a lysogenic prophage to a lytic cycle

Polarize

in cladistics, to determine whether character states are ancestral or derived

Polyphyletic

in phylogenetic classification, a group that does not include the most recent common ancestor of all members of the group

Monophyletic

in phylogenetic classification, a group that includes the most recent common ancestor of the group and all its descendants. A clade is a monophyletic group.

Paraphyletic

in phylogenetic classification, a group that includes the most recent common ancestor of the group, but not all its descendants

Synapomorphy

in systematics, a derived character that is shared by clade members; best mechanism to analyze the evolutionary sequence in the development of a complex character (I remember this by saying the derived (new) characters are synapy...synapomorphy)

prions.

Recently a class of infectious proteins with no associated nucleic acid have been identified. They are referred to as bacteriophages. latent viruses. viroids. prions. virions.

Apomorphy

Derived trait.

Prokaryote facts

1) oldest organisms on Earth with fossils ~3.5 billion years old 2) structurally simplest organisms 3) most abundant life forms on earth 4) 90-99% unknown and undescribed. 5) lack a membrane bound nucleus and other organelles or cell inclusions. 6) Lack of cell compartments. 7) Include 2 domains Bacteria and Archaea. Consider: Archaea and Eukarya share nucleic acid similarities so Eukarya split off from Archaea

E) phylogeny.

1. The evolutionary history of a species or group of species is most accurately referred to as: A) systematics. B) ontogeny. C) taxonomy. D) bioinformatics. E) phylogeny.

C. Plasmodium.

1. The parasite that is responsible for causing malaria is called A. Streptococcus. B. Chlamydomonas. C. Plasmodium. D. Entamoeba. E. Giardia.

D. bacillus, coccus, and spirillum.

1. The three shapes of bacteria are A. haplontic, diplontic, and alternations. B. anaerobic, aerobic, and facultative. C. heterotrophic, autotrophic, and chemosynthetic. D. bacillus, coccus, and spirillum. E. helical, spiral, and streptococci.

Bacteria differing from Achaea

1. cell wall composition 2. plasma membrane make-up 3. DNA replication 4. gene expression 5. Bacteria have peptidoglycan which Archae lack. Consider: Archaea are able to live in the most extreme environments.

Prokaryotic metabolism

1. photoautotrophs carry out photosynthesis (cyanobacteria use chlorophyll a) 2. chemolithoautotrophs - energy through oxidizing inorganic substances (nitrifiers oxidize ammonia or nitrite to obtain energy, producing nitrate that is taken up by plants) 3. photoheterotrophs - purple and green nonsulfur bacteria use light as energy source and carbon from organic molecules 4. chemoheterotrophs - obtain both carbon atoms and energy from organic molecules (humans)

C. The lamprey is the only outgroup since it shares none of the derived characteristics.

10. Choose the true statement about the morphological data in the chart shown below. The "1" in the box means the trait is present and the "0" indicates that the trait is absent. A. All organisms in this chart share all of the derived characteristics. B. Only the gorilla and humans share all of the derived characteristics. C. The lamprey is the only outgroup since it shares none of the derived characteristics. D. The salamander and the tiger are outgroups because they only share two of the derived characteristics (jaws and lungs). E. The shark is an outgroup since it only has one of the derived characteristics (jaws).

D. headaches and nausea

2. The classic symptoms of malaria are: A. jaundice B. abdominal cramps C. diarrhea and dehydration D. headaches and nausea E. alternating chills and fever

D. whether their cell walls have a thin or thick layer of peptidoglycan.

2. The response of bacteria that allows them to be identified as Gram-positive or negative is due to A. the type of DNA or RNA they contain. B. their ability or lack of ability to fix nitrogen. C. whether they are aerobic or anaerobic. D. whether their cell walls have a thin or thick layer of peptidoglycan. E. the rRNA sequences they demonstrate.

E) (A), (B) and (C)

2. Which one of the following do all three domains of life have in common? A) the same genetic code B) plasma membranes C) glycolysis D) (A) and (C) E) (A), (B) and (C)

Kinetoplastids

2nd major group in Euglenozoa Unique, single mitochondrion DNA maxicircles and minicircles Trypanosomes cause human diseases African sleeping sickness - tsetse fly Leishmaniasis - sand fly - cause severe lesions Chagas disease - skin contact with urine or blood of infected wild animal. Heart affected by parasite and increases in size.

Influenza virus

3 major types of flu virus (A< B< and C), only Type A can occur in human, other mammals, and birds; the flu subtype is determined by the kinds of proteins representing the H and N protein spikes making up the capsid of the virus; different strains of the virus requires different vaccines; genetic high mutation rates is primarily responsible for the high diversity in strains; genetic recombination between flu strains from different species is common

A) symplesiomorphy.

3. In a cladistic approach to phylogeny, a trait shared with a distant common ancestor is referred to as a(n): A) symplesiomorphy. B) ingroup. C) synapomorphy. D) outgroup. E) shared derived character.

A. Liver and red blood cells

3. In malaria, Plasmodium falciparum grow inside of which human cells? A. Liver and red blood cells B. Liver cells C. Red blood cells D. Intestinal cells E. Liver and intestinal cells

B. bacteria

3. Which type of organism will form endospores when faced with unfavorable environmental conditions? A. viruses B. bacteria C. algae D. protozoans E. fungi

A. transformation.

4. Bacterial cells pick up free pieces of DNA from the medium-pieces that were released from dead bacteria-in a process called A. transformation. B. transduction. C. conjugation. D. infection. E. replication.

B) nonsulfur purple bacterium.

4. The mitochondria of eukaryotic cells most likely arose as a result of endosymbiosis between a eukaryotic cell and a A) blue-green alga. B) nonsulfur purple bacterium. C) red alga. D) cyanobacterium.

D) the preferred hypothesis is the one that is the simplest.

4. The principle of parsimony suggests that: A) neutral mutations occur at a fairly constant rate over time. B) the most accurate phylogenetic tree is the one with the most tips. C) species grouped into larger taxa for a cladogram should be from a single clade for the results to be reliable. D) the preferred hypothesis is the one that is the simplest. E) None of the above accurately describes the principle of parsimony.

E) polyphyletic

5. A __________ taxon consists of members of several evolutionary lines and does not include the most recent common ancestor of the included lineages. A) parsimonious B) paraphyletic C) monophyletic D) chronophyletic E) polyphyletic

C) they are not fungi, animals, or plants.

5. The protists are a paraphyletic group that have traditionally been grouped together because A) they are all genetically similar to each other. B) they all have very similar morphological characters. C) they are not fungi, animals, or plants. D) they all have similar nutritional modes and live in similar environments.

C. Archaea and Eukarya share nucleic acid similarities so Eukarya split off from Archaea.

5. What is the evolutionary relationship among Archaea, Bacteria, and Eukarya? A. Since Archaea are the most primitive, Archaean ancestors gave rise to bacteria that in turn gave rise to eukaryotes. B. All three domains are equally distant from the most primitive common ancestor, a protocell. C. Archaea and Eukarya share nucleic acid similarities so Eukarya split off from Archaea. D. Bacterial ancestors gave rise to both Archaea and to eukaryotes as two separate side branches. E. Archaea ancestors gave rise to both bacteria and to eukaryotes as two separate side branches.

A. polyphyletic

6. Many researchers who study the kingdom Protista argue that all of these organisms should not be placed in the same kingdom, because these organisms could not have evolved from a common ancestor. In other words, they argue that the kingdom Protista is _____. A. polyphyletic B. paraphyletic C. monophyletic D. heterophyletic E. none of the above

E. viruses

6. Which of the following is considered to be noncellular? A. bacteria B. fungi C. algae D. protozoans E. viruses

E) All of the above statements about protists are correct.

6. Which one of the following statements about protists is incorrect? A) Protists are most commonly found in moist environments. B) Protists are eukaryotic organisms. C) The organism that causes malaria is a protist. D) At least half of the oxygen in the atmosphere is produced by protists. E) All of the above statements about protists are correct.

C. taxonomy.

7. The science of describing, naming, and classifying extant and extinct organisms is A. evolution. B. phylogeny. C. taxonomy. D. nomenclature. E. biology.

D) chemotrophy

7. Which one of the following is not a basic type of protist nutrition? A) osmotrophy B) mixotrophy C) autotrophy D) chemotrophy E) phagotrophy

C. the wing of a bat and the arm of a human

8. Which of the following would be homologous structures? A. the wing of a bird and the wing of a bee B. the wing of a bee and the wing of a bat C. the wing of a bat and the arm of a human D. All of these answers are correct.

A. a common ancestor but not all of its descendants.

9. A paraphyletic group contains A. a common ancestor but not all of its descendants. B. groups of species with different common ancestors. C. a common ancestor and all of its descendants. D. a common ancestor and all of its descendants but not the most recent common ancestor. E. every species ever derived from a common ancestor

Outgroup

An organism that is considered not to be part of the group in question, but is closely related to the group. The evolutionary conclusion from this is that the ________ branched from the parent group before the other two groups branched from each other. a more distantly related group (not part of the clade: ancestor and all descendants that share a derived character state called synapomorphy)

No, viruses are non-living and cannot die.

Can a virus be killed? Yes, destroying its genome kills it. No, viruses are capable of self-assembly and cannot be permanently killed. Yes, separating the genes from the capsid kills it. No, viruses are non-living and cannot die.

Beneficial bacteria

Decomposers play an important role in the environment. Decomposition differences between a fish caught in Canada and Florida when put on ice???

Domains.

Eukarya, Archaea (small, single celled, cell wall, no nucleus, can live in extreme conditions) , Bacteria (greatest # niches) Kingdoms of Plantae, Fungi, Animalia and Protista are all in the Eukarya Domain - What are the main derived characters (synapomorphy) that differentiates these kingdoms? Consider: The traits that all 3 domains have in common are hypothesized to be the result of all 3 domains evolving from a common prokaryotic ancestor. Those traits are that all species use the same genetic code (very few exceptions), plasma membranes, and glycolysis. Consider : Above are the two suggested hypothesis on how these groups are related: "archaea tree" or "eocyte tree"

Ciliates

Feature large numbers of cilia arranged in longitudinal rows or spirals around the cell Pellicle - tough but flexible outer covering 2 types of nuclei Micronucleus - without will reproduce asexually Macronucleus - essential for function Have two types of vacuoles Food vacuoles - digestion of food Contractile vacuoles - regulation of water balance

Certain parts of the viral genome are reshuffled by mutations and recombination.

Flu shots are vaccines against the most common strains of the flu virus. Most vaccines are rarely changed but new flu vaccines are produced every year. Why are flu shots constantly being reformulated? The flu virus is not completely known. Certain parts of the viral genome are reshuffled by mutations and recombination. The virus mixes with prions. The virus shifts from RNA to DNA.

Multicellularity

From single cells to colonies to true multicellularity Arisen multiple times Fosters specialization Few innovations have had as great an influence on the history of life

Shapes

Helical (usually plant viruses) Icosahedral with or without an envelope (usually animal viruses) Complex binary (infects bacteria)

Character state

In cladistics, one of two or more distinguishable forms of a character, such as the presence or absence of teeth in amniote vertebrates

Protists

Kingdom includes all eukaryotes (such as protozoa, some algae, water molds, slime molds, etc) except green plants, animals and fungi (allows them to be classified into one kingdom)....most diverse of four eukaryotic kingdoms, not monophyletic ( means that all protists are not more closely related to each other than they are to some other kinds of organisms); majority reproduce asexually most of the time, but under stress conditions will reproduce sexually. Most are small (microscopic) but some are huge (100 meters). Note: Some algae are not considered plants because they lack plant structures such as roots and placed among Protists. Green algae are now grouped with plants.

Eukaryotes

Major differences between prokaryotes and eukaryotes: cytoskeleton and compartmentalization (membrane bound nucleus and organelles). Understand the origin including primary and secondary endosymbiosis. Note: How do we know that endosymbiosis really occurred? How did these evolution events help eukaryotes?

Green Algae

Only once in evolution these algae gave rise to all land plants. Have 2 monophyletic groups: Chlorophyta and charophytes. Diverged from land plants over 1BYA. Can be single cell, multicellular or colonial.

Science

Production of knowledge

Scientific Method

Technique used worldwide to produce knowledge. Question-Background research-Hypothesis-experiment to test hypothesis- analyze results then accept or reject hypothesis.

latent

The HIV virus is considered a(n) ______ virus, because after getting integrated into the host cell chromosomes, it does not begin replicating immediately. phage latent transforming benign inducible

Microbiome

The full array of microorganisms (the microbiota) that live on and in humans and, more specifically, the collection of microbial genomes that contribute to the broader genetic portrait, or metagenome, of a human. The genomes that constitute the human microbiome represent a remarkably diverse array of microorganisms that includes bacteria, archaea, fungi, and even some protozoans and nonliving viruses. Bacteria are by far the most numerous members of the human microbiome: the bacterial population alone is estimated at between 75 trillion and 200 trillion individual organisms, while the entire human body consists of about 50 trillion to 100 trillion somatic (body) cells.

Symbiosis

Types of symbiotic relationship and influence on evolution. (Mutualism, Commensalism and Parasitism)

Diplomonads

Unicellular Move with flagella 2 nuclei Giardia (causes diarrhea) Lack mitochondria but have some mitochondrial genes in their DNA.

Host range

Usually limited host range

Important human viruses

Virus Classification by genome structure and Core (table 21.1).

being capable of independent reproduction.

Viruses are characterized by all of the following except being found in every organism investigated so far. being specific to the hosts they infect. being capable of independent reproduction. being acellular.

Cladogram.

a graphical representation of possible evolutionary relationships, based on polarization of characters, in which taxa are placed at the tips, not at the branch points, of the phylogenetic tree and shared, derived characteristics common to taxa above the branch point are placed at the branch point. Helps with the studies in evolution, ecology, biogeography and even forensics. Consider: Steps to construct a cladogram would be - 1. gather data on characters to be used, 2. establish the character states (teeth), 3. polarize the characters (ancestral or derived) 4. select an outgroup (closely related to but not a member) 5. apply principle of parsimony (hypothesis that requires the fewest assumptions)

Clade

a group containing all descendants of a common ancestor

Cladistics

a taxonomic technique used for creating hierarchies or organisms that represent true phylogenetic relationship and descent. This technique has multiple uses including the HIV court case.

Nucleoid region

area where prokaryotic DNA is found (no membrane)

Prokaryote modern classification

based on sequencing of proteins, DNA and RNA

Virus structure (smaller than bacteria)

capsid, nucleic acid core, envelope, spike measured in the nm range Consider: Viruses are obligate intracellular parasites that do not themselves possess a cell. They are, essentially, chemical complexes of RNA or DNA protected by protein. A virus particle (outside host) can also be referred to as a virion.

Virulent virus

causes lysis of their hosts (lytic); Consider: (Refer to illustration below) A virulent virus is one that infects the host cell and enters into the lytic stage causing replication of virus and lysis of the host cell to release these produced viruses. A temperate virus is one that can incorporate its genome into the host cell's genome and remain dormant, only reproducing as the host cell reproduces itself (lysogenic stage). But the virus genome can become activated and it can enter a lytic stage.

Prokaryotes differing from eukaryotes

cell size, multicellularity, chromosomes, organelles, reproduction Note: Eukaryotes and Prokaryotes both have ribosomes.

Ancestral characteristics

characteristics that have arisen in organisms as a result of common evolutionary descent

Spike

glycoproteins that project from some enveloped viruses allowing for attachment of the virus to the targeted host cell

Cyanobacteria

group of bacteria that produced oxygen and changed the Earth's atmosphere from an anoxic one to one rich in oxygen

Prokaryote structure (bacteria)

have cell walls consisting of a network of polysaccharides connected by cross links of polypeptides (peptidoglycan) flagella - used for movement have enzymes used for cellular respiration attached to cell membrane have 3 shapes (due to cell walls): bacillus, coccus, and spirillum can form biofilms

Retrovirus

have the enzyme reverse transcriptase high error rate of reverse transcriptase leads to high genetic diversity of HIV; this in turn creates difficulty in creation of vaccine direction of genetic information transfer in a retrovirus (such as HIV) is RNA to DNA to mRNA to protein

Lytic cycle

host cell lyses, releasing many viral particles

Homoplasy

in cladistics, a shared character state that has not been inherited from a common ancestor exhibiting that state; may result from convergent evolution or evolutionary reversal. The wings of birds and of bats, which are convergent

Symplesiomorphy

in cladistics, another term for a shared ancestral/primitive or outgroup character state (I remember this by saying the primitive trait is the most symplesiomorphy)

Plesiomorphy

in cladistics, another term for an ancestral character state

Nucleic acid core

inner most portion is made of DNA or RNA

Lysogenic cycle

integration and stabilizing of viral genes into the host cell's genome

Exchange of genetic material via horizontal transfer

occurs through conjugation (depends on presence of conjugative plasmids when genes are transferred through rigid, tubular sex pili), transduction (occurs when viruses (bacteriophage) package host DNA and transfer it upon subsequent infection), transformation (bacterial cells pick up free pieces of DNA from the medium-pieces that were released from dead bacteria), and exchange of R plasmids (plasmids are different from bacterial chromosomes in that plasmids have few genes, bacterial chromosome have many) increases genetic diversity; helps infer phylogeny; common occurrence in bacteria; can produce large genetic change

Obligate anaerobe

organisms poisoned by oxygen

Capsid

outer layer composed of protein subunits; protein on surface can interact with a protein on the surface of the host cell

Prophage

parasitic viral DNA that has been integrated into the chromosome of its bacterial host

Tissue tropism

targeting of specific range of cells within suitable organism

Fungi

taxa with a cell wall, external digestion, and lacking photosynthesis capability

Ingroup

the "study group"

Biological species concept (BSC)

the concept that defines species as groups of populations that have the potential to interbreed and that are reproductively isolated from other groups

Phylogenetic species concept (PSC)

the concept that defines species on the basis of their phylogenetic relationships

Phylogeny.

the evolutionary history of an organism, including which species are closely related and in what order related species evolved; often represented in the form or an evolutionary tree that are constructed based on morphological analysis, DNA sequences, and geographical information Consider: Phylogenetically based taxonomy helps us learn about traits in organisms using information in related species. These traits can also include physiology, development, and behavior.

Sister group

the group that is genealogically most closely related to the ingroup, and included for comparative purposes; we can conclude that species D is more closely related to species E than it is to species A.

Viroids

they are tiny, naked molecules of RNA a few hundred nucleotides long whose sequence resembles intron sequences in rRNA genes; they are causative agents of plant diseases

Endospores

thick-walled structures that contain chromosome and small amount of cytoplasm...these are formed in response to environmental stress (e.g., low nutrients)

Nitrogen fixation and use

this pathway begins with atmospheric nitrogen ( Dinitrogen; unusable by plants in this form because of strength of N-N triple bond), bacterial nitrogenase(enzyme that catalyzes the reactions); ammonia; conversion by plants or algae; synthesis of proteins

Horizontal gene transfer

transfer of genes between different species, both prokaryotic or eukaryotic

Emerging virus

virus in a new host with a potential lethality rate in excess of 50%; example is Ebola virus; these viruses are able to jump from one species to another; hantavirus originates in deer mice and causes hemorrhagic-type fever; SARS is completely new form of corona virus

Latent virus

virus is able to hide from host's immune system by integrating itself into the host cell's genome and not producing new viruses...e.g., chickenpox may be followed, years later, with shingles with both the result of the same viral infection.

Bacteriophages

viruses that can infect bacteria