Micro Exam 3

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Questions and Answers

How many categories are used to classify life?

8 (correct)

Name the 8 classifications of life from most inclusive to least inclusive

1.Domain 2.Kingdom 3.Phylum 4.Class 5.Order 6.Family 7.Genus 8.Species

Which branch of biology is concerned with the naming and classifying of organisms?

Bioinformatics

Taxonomy (correct)

Genomics

Evolution

What are the 3 domains of life?

Bacteria,Archaea, Eukarya Signup and view all the answers

Prokaryotes are __-cellular organisms

Unicelluar Signup and view all the answers

Eukaryotes can be multicellular or unicellular

True Signup and view all the answers

Prokaryotes include...

Bacteria and Archaea Signup and view all the answers

Give an example of eukaryotes

Humans Signup and view all the answers

Who introduced a formal classification system with two kingdoms, Plantae and Animalia?

Carolus Linnaeus Signup and view all the answers

In the five-kingdom system proposed by Robert H. Whittaker, prokaryotes were placed in which kingdom?

Monera Signup and view all the answers

Which scientist proposed the elevation of three cell types to a level above kingdom, introducing the concept of domains?

Carl R. Woese Signup and view all the answers

What distinguishes the three domains proposed by Carl R. Woese from each other?

Differences in membrane lipid structure, transfer RNA molecules, and sensitivity to antibiotics Signup and view all the answers

What major advancement in biological classification was based on observations about ribosomes and nucleotide sequences?

Discovery of two types of prokaryotic cells and one type of eukaryotic cell Signup and view all the answers

What is the primary difference in reproduction methods between eukaryotic cells and archaea?

Eukaryotes reproduce sexually to form diploid zygotes, while archaea reproduce asexually through the production of haploid spores. Signup and view all the answers

Which of the following is a key difference in the cellular structure between eukaryotic cells and archaea?

Eukaryotic cells have a complex network of organelles, such as mitochondria and chloroplasts, while archaea lack these membrane-bound organelles. Signup and view all the answers

Which of the following is a key difference in the genetic makeup between archaea and bacteria?

Archaea possess unique flagellins for motility Signup and view all the answers

Identify the correct order of taxonomic hierarchy

Domain = 1. Most inclusive classification Kingdom = 2. Phillip = 3. Class = 4. Signup and view all the answers

Identify the correct order of taxonomic hierarchy

Order = 5. Family = 6. Genus = 7. Species = 8. Least Inclusive Signup and view all the answers

Which are serological methods? Which are DNA Hybridization methods?

Western Blotting = Serological Method Northern Blotting = DNA Hybirdization ELISA = Serological Method Southern Blotting = DNA Hybirdization Signup and view all the answers

Which are serological methods? Which are DNA Hybridization methods?

Rapid Diagnostic Tests = serological methods Agglutination Tests = serological methods Fluorescence In Situ Hybridization = DNA Hybridization PCR = DNA Hybridization Signup and view all the answers

Who is the guilty one?

Suspect 2 Signup and view all the answers

What is southern blotting?

A technique used to rapidly detect a specific DNA sequence using DNA probes Signup and view all the answers

Which definition fits Western blotting?

A technique that uses antibodies to detect the presence of specific proteins separated by electrophoresis Signup and view all the answers

What is a cladogram?

Shows phylogenetic relationships among organisms Signup and view all the answers

Which of the following criteria is most useful in determining whether two organisms are related?

Both are gram-positive. Signup and view all the answers

Which test involves preparing suspensions of an unknown bacterium in saline, adding different antisera, and checking for clumping?

slide agglutination Signup and view all the answers

Which statement regarding viral species is true?

Viral species are not classified as part of any of the three domains. Signup and view all the answers

The three domains of life include the Bacteria, Archaea, and Eukarya. For this activity, the description of each group or examples from a group must be matched with the appropriate location in the image depicting the three domain classification of living things. Drag the description to the appropriate location on the image depicting the three domains system.

A. Prokaryotes that grow in extremely hot enviromets. B. Prokaryotes that require a high concentration of salt to survive C. Includes prokaryotes with peptidoglycan and also photosynthetic prokaryotes. D. Includes prokaryotes that do not have peptidoglycan in their cell walls. E. Includes the Kingdoms, Plantae, Fungi, and Animalia Signup and view all the answers

Match organisms that can be classified under Archaea

Extreme Halophiles = Archaea Hyperthermophiles = Archaea Methanogens = Archaea Gram+ bacteria = Not Archaea Signup and view all the answers

Match organisms that can be classified under Bacteria

Cyanobacteria = Bacteria Gram+bacteria = Bacteria Proteobacteria = Bacteria Fungi = Not Bacteria Signup and view all the answers

Match the organisms that can be classified under Eukarya

Fungi = Eukarya Slime Molds = Eukarya Green Algae = Eukarya Ciliates = Eukarya Signup and view all the answers

Members of the Domain Archaea are characterized by all of the following except:

Contain nuclei Signup and view all the answers

A unicellular, photosynthetic nucleated cell would belong to Domain:

Eukarya Signup and view all the answers

The first cells were formed approximately ___________ years ago.

3 billion years ago Signup and view all the answers

Which of the following is the original basis for differentiation of the three domains of life?

Ribosomal RNA sequences Signup and view all the answers

How many answers are there to a question in a dichotomous key flowchart?

Two Signup and view all the answers

Why are flowcharts useful for dichotomous keys?

They allow the researcher to visualize relationships between different bacteria. Signup and view all the answers

The first question in this dichotomous key addresses

Gram stain differences. Signup and view all the answers

Numerical identification methods rely on a series of which kind of tests to identify microorganisms?

biochemical testing Signup and view all the answers

Which contains all the information of the other three

cladogram Signup and view all the answers

Organisms once classified as protists are now being divided into which of the following?

clades Signup and view all the answers

Which technique is often used to determine the identity and abundance of microorganisms in an environment? (This technique is particularly useful because it does not require culturing the organisms.)

fluorescent in situ hybridization (FISH) Signup and view all the answers

A nucleic acid hybridization experiment produced the following results. In the figure, which figure shows the most closely related organisms?

b Signup and view all the answers

Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?

Proteobacteria (gram-negative bacteria) Signup and view all the answers

Why is visualization not sufficient to properly identify bacteria?

Bacteria have a limited set of shapes and many unrelated bacteria share the same shape Signup and view all the answers

What is the hallmark of dichotomous keys?

They consist of a series of paired statements, in which only one statement of each pair applies to a given organism. Signup and view all the answers

Biochemical tests _________________.

are the main methods used to identify unknown bacteria Signup and view all the answers

Which of the following techniques could be used to identify antibodies produced by a patient?

Western blotting Signup and view all the answers

Which type of organism would NOT be included in the Domain Eukarya?

bacterium Signup and view all the answers

For a serological bacterial identification test to be performed, you must have ________ in your possession.

antiserum containing antibodies that will bind to the bacterium to be identified Signup and view all the answers

In the table, which feature(s) is (are) found only in prokaryotes?

4, 6 Signup and view all the answers

Consider a gram-negative pathogen isolated from marine mammals. This pathogen is subjected to a series of tests and found to have the following characteristics: oxidase-positive, does not hydrolyze urea, produces indole, does not produce acetoin. Which of the following could it be?

Pasteurella multocida Signup and view all the answers

Into which group would you place a multicellular heterotroph with chitin cell walls?

Fungi Signup and view all the answers

Which of the following groups in the Domain Archaea require high salt concentrations for survival?

halophiles Signup and view all the answers

Organism A has 70 moles % G+C, and organism B has 40 moles % G+C. Which of the following can be concluded from these data?

The two organisms are unrelated. Signup and view all the answers

Bergey’s Manual of Systematic Bacteriology differs from Bergey’s Manual of Determinative Bacteriology in that the former

groups bacteria according to phylogenetic relationships. Signup and view all the answers

Bacillus and Lactobacillus are not in the same order. This indicates that which one of the following is not sufficient to assign an organism to a taxon?

morphological characteristics Signup and view all the answers

Which of the following is used to classify organisms into the Kingdom Fungi?

absorptive; possess cell wall; eukaryotic Signup and view all the answers

Which of the following is false about scientific nomenclature?

Names vary with geographical location. Signup and view all the answers

You could identify an unknown bacterium by all of the following except

percentage of guanine + cytosine. Signup and view all the answers

The wall-less mycoplasmas are considered to be related to gram-positive bacteria . Which of the following would provide the most compelling evidence for this?

They share common rRNA sequences. Signup and view all the answers

Into which group would you place a multicellular organism that has a mouth and lives inside the human liver?

Animalia Signup and view all the answers

Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?

Proteobacteria (gram-negative bacteria) Signup and view all the answers

Which is (are) found in all three domains?

2, 6 Signup and view all the answers

Which is (are) found only in prokaryotes?

3, 5 Signup and view all the answers

If you Gram-stained the bacteria that live in the human intestine, you would expect to find mostly

gram-negative rods Signup and view all the answers

Which of the following does not belong with the others?

Lactobacillales Signup and view all the answers

Pathogenic bacteria can be

all of the above Signup and view all the answers

Which of the following is an intracellular parasite?

Rickettsia Signup and view all the answers

Which of the following terms is the most specific?

Bacillus (italicized) Signup and view all the answers

Which one of the following does not belong with the others?

Staphylococcus Signup and view all the answers

Which of the following pairs is mismatched?

spirochete—Helicobacter Signup and view all the answers

Spirillum is not classified as a spirochete because spirochetes

possess axial filaments Signup and view all the answers

When Legionella was newly discovered, why was it classified with the pseudomonads?

It is an aerobic gram-negative rod. Signup and view all the answers

Unlike purple and green phototrophic bacteria, cyanobacteria

produce oxygen during photosynthesis. Signup and view all the answers

All of the following bacteria are motile. Which does NOT have flagella?

spirochetes Signup and view all the answers

Rickettsias differ from chlamydias in that rickettsias

require an arthropod for transmission. Signup and view all the answers

Bacteroides

are found in gingival crevices and in the intestinal tract Signup and view all the answers

The characteristic most notable regarding the mycoplasmas is that they

lack cell walls. Signup and view all the answers

Members of which group or genus of Archaea are part of the microbiota of the human colon, vagina, and mouth?

Methanogens Signup and view all the answers

Which one of the following does NOT belong with the others?

Staphylococcus Signup and view all the answers

Which one of the following bacteria does NOT belong with the other betaproteobacteria?

Salmonella Signup and view all the answers

Which of the following genera can be described as a non-motile aerobic gram negative rod?

Bordetella Signup and view all the answers

Which of the following factors is believed to limit the size of most bacterial cells?

the fact that nutrients must enter the cells by simple diffusion Signup and view all the answers

Regarding the Order Rhizobiales of the Class alphaproteobacteria, which genus includes human pathogens?

Brucella Signup and view all the answers

You have isolated and grown a pure culture of a prokaryotic cell type. The first step in identification is a(n)

Gram stain. Signup and view all the answers

Which gammaproteobacteria are facultatively anaerobic, Gram-negative rods that inhabit the intestinal tracts of humans and other animals?

Enterobacteriales Signup and view all the answers

Gram-positive organisms with high G+C content are in the phylum __________.

Actinobacteria Signup and view all the answers

You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong?

bacillales Signup and view all the answers

A primary difference between cyanobacteria and purple and green photosynthesizing bacteria is

electron donor for CO2 reduction. Signup and view all the answers

Streptomyces differs from Actinomyces because Streptomyces

is a strict aerobe. Signup and view all the answers

Which of the following photosynthetic bacteria carries out oxygenic photosynthesis and most likely altered Earth's atmosphere by significantly contributing to the accumulation of oxygen gas?

Cyanobacteria, such as Anabaena and Prochlorococcus Signup and view all the answers

You have isolated a gram-positive bacterium with low G + C content from unpasteurized milk. It infected a pregnant woman, and now you are worried that her child will be stillborn. What bacterium is it?

Listeria monocytogenes Signup and view all the answers

Which of the following is NOT an enteric?

Campylobacter Signup and view all the answers

If a patient is diagnosed with a peptic ulcer, which genus of proteobacteria is probably responsible?

Helicobacter Signup and view all the answers

Which one of the following bacteria does NOT belong with the others?

Escherichia Signup and view all the answers

Which of the following is NOT a characteristic of Neisseria?

requires X and V factors Signup and view all the answers

Which of the following form conidiospores?

actinomycetes and related organisms Signup and view all the answers

If a typhoid fever outbreak has occurred, which of the following statements is true?

Salmonella is present, and the serovars may be differentiated by antigenic analysis Signup and view all the answers

Blood agar would be the culture medium of choice if one were testing a patient for which of the following?

scarlet fever Signup and view all the answers

How many phyla are represented in the following list of organisms: Echinococcus, Cyclospora, Aspergillus, Taenia, Toxoplasma, Trichinella?

4 Signup and view all the answers

How many phyla are represented in the following list of organisms: Echinococcus, Cyclospora, Aspergillus, Taenia, Toxoplasma, Trichinella?

metacercaria

redia

adult

miracidium

cercaria

4, 2, 5, 1, 3 Signup and view all the answers

If a snail is the first intermediate host of a parasite with these stages, which stage would be found in the snail?

redia Signup and view all the answers

Fleas are the intermediate host for Dipylidium caninum tapeworm, and dogs are the definitive host. Which stage of the parasite could be found in the flea?

cysticercus larva Signup and view all the answers

Which of the following statements about yeasts are true? Yeasts are fungi. Yeasts can form pseudohyphae. Yeasts reproduce asexually by budding. Yeasts are facultatively anaerobic. All yeasts are pathogenic. All yeasts are dimorphic.

1, 2, 3, 4 Signup and view all the answers

Which of the following events follows cell fusion in an ascomycete?

ascospore formation Signup and view all the answers

The definitive host for Plasmodium vivax is

Anopheles Signup and view all the answers

These are obligate intracellular parasites that lack mitochondria.

Microsporidia Signup and view all the answers

These are nonmotile parasites with special organelles for penetrating host tissue.

Apicomplexa Signup and view all the answers

These photosynthetic organisms can cause paralytic shellfish poisoning.

dinoflagellates Signup and view all the answers

Which of the following organisms is photoautotrophic protozoan?

Euglena Signup and view all the answers

In the malaria parasite life cycle, humans are the host, while mosquitoes are the host as well as the vector.

intermediate; definitive Signup and view all the answers

1-Arthroconidium 5-Chlamydoconidium 2-Ascospore 6-Conidiospore 3-Basidiospore 7-Sporangiospore 4-Blastoconidium 8-Zygospore In the table, which is a thick-walled spore formed as a segment within a hypha?

5 Signup and view all the answers

All of the following are characteristic of lichens EXCEPT

they are a symbiotic relationship between a fungus and a protozoan. Signup and view all the answers

Humans are the definitive host for , which is a type of .

Taenia saginata; tapeworm Signup and view all the answers

In the microscope, you observe multinucleated amoeboid cells with sporangia that form spores. This is a(n)

plasmodial slime mold. Signup and view all the answers

Which of the following statements regarding fungi is FALSE?

Most fungi are pathogenic for humans. Signup and view all the answers

Which of the following statements is FALSE?

Fungal spores are highly resistant to heat and chemical agents. Signup and view all the answers

Dengue fever and Zika virus are transmitted by which of the following?

mosquitoes Signup and view all the answers

Which phylum of protozoa contains organisms that are non-motile, obligate intracellular parasites?

Apicomplexa Signup and view all the answers

Seventeen patients in ten hospitals had cutaneous infections caused by Rhizopus. In all seventeen patients, Elastoplast bandages were placed over sterile gauze pads to cover wounds. Fourteen of the patients had surgical wounds, two had venous line insertion sites, and one had a bite wound. Lesions present when the bandages were removed ranged from vesiculopustular eruptions to ulcerations and skin necrosis requiring debridement. Fungi are more likely than bacteria to contaminate bandages because they

can tolerate low-moisture conditions. Signup and view all the answers

Which of the following statements about fungi is true?

Karyogamy refers to a part of the sexual reproduction cycle in which two haploid nuclei fuse to form a diploid zygote. Signup and view all the answers

Trichomonas vaginalis can be distinguished from other parasitic protozoa by which of the characteristics listed below?

It has an undulating membrane, infects the vagina, and is frequently transmitted by sexual contact. Signup and view all the answers

A wolf kills a deer that is infected with of Echinococcus granulosis in its liver and eats it. After consuming the deer, the wolf's intestine becomes filled with a number of produced from scoleces. These eventually release eggs into the wolf's intestines, which are released in its feces.

hydatid cysts; proglottids Signup and view all the answers

Which of the following groups of algae does NOT produce compounds that are toxic to humans?

green algae Signup and view all the answers

The encysted larva of the beef tapeworm is called a

cysticercus. Signup and view all the answers

Which of the following pairs is mismatched?

cestodes – all are free-living Signup and view all the answers

Which of the following statements about protozoa is true?

When conditions become harsh, some protozoa can form a protective capsule, which is called a cyst. Signup and view all the answers

Which of the following organisms requires an additional non-human host to complete its life cycle?

Plasmodium species Signup and view all the answers

Infecting more than 2 billion people worldwide, ________ are the most common causes of chronic infectious diseases.

intestinal roundworms Signup and view all the answers

Which of the following tends to be more complex in a parasitic helminth than in free-living helminths?

reproductive system Signup and view all the answers

The term dermatophyte is typically used for fungi that cause which of the following?

cutaneous mycoses Signup and view all the answers

1-Arthroconidium 5-Chlamydoconidium 2-Ascospore 6-Conidiospore 3-Basidiospore 7-Sporangiospore 4-Blastoconidium 8-Zygospore In the table, which of these spores are asexual spores?

1, 4, 5, 6, 7 Signup and view all the answers

The cells of plasmodial slime molds can grow to several centimeters in diameter because

they distribute nutrients by cytoplasmic streaming. Signup and view all the answers

Dinoflagellates are a type of unicellular . One genus of dinoflagellates is responsible for a foodborne disease called .

algae; paralytic shellfish poisoning (PSP Signup and view all the answers

Which statement regarding helminths is true?

Helminths usually possess specialized organ systems, including circulatory, nervous, and reproductive systems. Signup and view all the answers

Place the following in the most likely order for biosynthesis of a bacteriophage: (1) phage lysozyme; (2) mRNA; (3) DNA; (4) viral proteins; (5) DNA polymerase.

2, 5, 3, 4, 1 Signup and view all the answers

The molecule serving as mRNA can be incorporated in the newly synthesized virus capsids of all of the following except

<ul> <li>strand RNA rhabdoviruses.</li> </ul> Signup and view all the answers

A virus with RNA-dependent RNA polymerase

synthesizes double-stranded RNA from an RNA template. Signup and view all the answers

Which of the following would be the first step in the biosynthesis of a virus with reverse transcriptase?

A complementary strand of RNA must be synthesized. Signup and view all the answers

An example of lysogeny in animals could be

latent viral infections. Signup and view all the answers

The ability of a virus to infect an organism is regulated by

all of the above Signup and view all the answers

Which of the following statements is false?

Viruses multiply inside living cells using viral mRNA, tRNA, and ribosomes. Signup and view all the answers

Place the following in the order in which they are found in a host cell: (1) capsid proteins; (2) infective phage particles; (3) phage nucleic acid.

3, 1, 2 Signup and view all the answers

Which of the following does not initiate DNA synthesis?

a single-stranded RNA virus (Togaviridae) Signup and view all the answers

A viral species is not defined on the basis of the disease symptoms it causes. The best example of this is

hepatitis. Signup and view all the answers

A viral species is a group of viruses that

has the same genetic information and ecological niche. Signup and view all the answers

A viral species is a group of viruses that

has the same genetic information and ecological niche. Signup and view all the answers

A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient?

The virus is causing the death of the infected cells in the patient. Signup and view all the answers

A persistent infection is one in which

the disease process occurs gradually over a long period. Signup and view all the answers

Which of the following is NOT used as a criterion to classify viruses?

biochemical tests Signup and view all the answers

Which of the following is true of viroids?

Viroids are short pieces of naked RNA. Signup and view all the answers

Continuous cell lines differ from primary cell lines in that

continuous cell lines can be maintained through an indefinite number of generations. Signup and view all the answers

Which of the following statements about viral spikes is FALSE?

They are found only on nonenveloped viruses Signup and view all the answers

Which of the following statements concerning prion diseases is true?

Normal host cellular prion proteins (PrPC) are converted into scrapie proteins (PrPSc). Signup and view all the answers

Which of the following is true regarding cultivation and isolation of animal viruses?

Diploid cell culture lines, developed from human embryos, are widely used for culturing viruses that require a human host. Signup and view all the answers

How do all viruses differ from bacteria?

Viruses are not composed of cells. Signup and view all the answers

Which of the following statements concerning viruses is true?

The "host range" for a virus is determined by the presence or absence of particular components on the surface of a host cell that are required for the virus to attach. Signup and view all the answers

Which of the following is true concerning a lysogenic viral replication cycle?

During lysogeny, the viral genome integrates into the host DNA, becoming a physical part of the chromosome. Signup and view all the answers

Generally, in an infection caused by a DNA-containing virus, the host animal cell supplies all of the following EXCEPT

DNA polymerase. Signup and view all the answers

Viruses that utilize reverse transcriptase belong to the virus families

Hepadnaviridae and Retroviridae Signup and view all the answers

A virus's ability to infect an animal cell depends primarily upon the

presence of receptor sites on the cell membrane. Signup and view all the answers

The most conclusive evidence that viruses cause cancers was provided by

cancer that developed in chickens following injection of cell-free filtrates. Signup and view all the answers

Which statement is INCORRECT concerning animal viruses?

The genome of animal viruses is always single-stranded. Signup and view all the answers

Which virus is NOT associated with cancer?

coronavirus Signup and view all the answers

were first identified in cancer-causing viruses and can induce in infected cells.

Oncogenes; transformation Signup and view all the answers

The definition of lysogeny is

phage DNA is incorporated into host cell DNA. Signup and view all the answers

Which statement concerning viral structure is true?

Spikes are found on some viruses. They are very consistent in structure within a viral species and can be used for identification. Signup and view all the answers

Why do most scientists agree that viruses are nonliving entities?

They are not composed of cells. Signup and view all the answers

A clear area against a confluent "lawn" of bacteria is called a

plaque. Signup and view all the answers

Each of the following can be used for the detection and/or identification of viruses except _______________.

fermentation tests Signup and view all the answers

Which of the following statements regarding latent viral infections is true?

Latent infections can persist for years in an individual without causing any symptoms. Signup and view all the answers

Why do we classify viruses as obligatory intracellular parasites?

Viruses absolutely require living host cells to multiply Signup and view all the answers

What is a virion?

a fully developed virus particle that transfers the viral nucleic acid to another cell and initiates multiplication. Signup and view all the answers

Compare biosynthesis of a + stranded RNA and a − stranded RNA virus.

Both produce double-stranded RNA, with the - strand being the template for more + strands. + strands act as mRNA in both virus groups. Signup and view all the answers

Some antibiotics activate phage genes. MRSA releasing Panton-Valentine leukocidin causes a life-threatening disease. Why can this happen following antibiotic treatment?

Antibiotic treatment of S. aureus can activate phage genes that encode P-V leukocidin. Signup and view all the answers

Recall from Chapter 1 that Koch’s postulates are used to determine the etiology of a disease. Why is it difficult to determine the etiology of a viral infection, such as influenza?

Viruses are hard to see in tissues, difficult to culture for inoculation, and require specific hosts, making it challenging to fulfill Koch's postulates. Signup and view all the answers

Recall from Chapter 1 that Koch’s postulates are used to determine the etiology of a disease. Why is it difficult to determine the etiology of cancer?

Some viruses don't cause cancer right away. Cancer might appear long after infection, and cancer doesn't seem to be contiguous Signup and view all the answers

Persistent viral infections such as (a) _____ might be caused by (b) _ that are ( c ) _______.

(a) subacute sclerosing panencephalitis, (b) common viruses ( c ) latent, in an abnormal tissue. Signup and view all the answers

Plant viruses can’t penetrate intact plant cells because (a) _____; therefore, they enter cells by (b) _. Plant viruses can be cultured in ( c ) _______.

(a) of the rigid cell walls (b) vectors such as sap-sucking insects ( c ) plant protoplasts and insect cell cultures Signup and view all the answers

Identify the viral family that infects skin, mucosa, and nerve cells; causes infections that can recur because of latency, and has polyhedral geometry

Herpesviridae Signup and view all the answers

A 40-year-old man who was seropositive for HIV experienced abdominal pain, fatigue, and low-grade fever (38°C) for 2 weeks. A chest X-ray examination revealed lung infiltrates. Gram and acid-fast stains were negative. A viral culture revealed the cause of his symptoms: a large, enveloped polyhedral virus with double-stranded DNA. What is the disease?

CMV DIsease Signup and view all the answers

A 40-year-old man who was seropositive for HIV experienced abdominal pain, fatigue, and low-grade fever (38°C) for 2 weeks. A chest X-ray examination revealed lung infiltrates. Gram and acid-fast stains were negative. A viral culture revealed the cause of his symptoms: a large, enveloped polyhedral virus with double-stranded DNA. Which virus causes it?

Cytomegalovirus Signup and view all the answers

A 40-year-old man who was seropositive for HIV experienced abdominal pain, fatigue, and low-grade fever (38°C) for 2 weeks. A chest X-ray examination revealed lung infiltrates. Gram and acid-fast stains were negative. A viral culture revealed the cause of his symptoms: a large, enveloped polyhedral virus with double-stranded DNA. Why was a viral culture done after the Gram and acid-fast stain results were obtained?

The Gram and acid-fast stains were negative, indicating that the cause of the symptoms might not be bacteria. So viral infection needed to be tested next Signup and view all the answers

A newborn female developed extensive vesicular and ulcerative lesions over her face and chest. What is the most likely cause of her symptoms?

Viral infection from HSV family Signup and view all the answers

A newborn female developed extensive vesicular and ulcerative lesions over her face and chest. How would you determine the viral cause of this disease without doing a viral culture?

Serology or Viral PCR Signup and view all the answers

By May 14, two people living in the same household had died within 5 days of each other. Their illnesses were characterized by abrupt onset of fever, muscle pain, headache, and cough, followed by the rapid development of respiratory failure. By the end of the year, 36 cases of this disease, with a 50% mortality rate, had been confirmed. A member of the Orthomyxoviridae, Bunyaviridae, or Adenoviridae could cause this disease. Differentiate among these families by method of transmission, morphology, nucleic acid, and type of replication. The reservoir for this disease is mice. Name the disease.

Hantavirus Pulmonary Syndrome caused by Bunyaviridae Signup and view all the answers

Viral species share similar genetic information and...

ecological niche. Signup and view all the answers

Which of the following statements accurately distinguishes between generalized and specialized transduction?

Generalized transduction involves the transfer of any genes from the host cell to another cell by a phage, whereas specialized transduction involves the transfer of specific genes from the host chromosome along with the viral DNA when a lysogenic phage is released. Signup and view all the answers

What are the major diffrences between bacteriophages and animal viruses?

Bacteriophages infect bacteria, while animal viruses infect animals. Bacteriophages have a complex structure with a head, sheath, and tail, while animal viruses vary in shape. Bacteriophages are easy to grow in culture, but animal viruses often need a living host. Signup and view all the answers

Where specifically does a DNA virus replicate in its host cell?

In the nucleus Signup and view all the answers

Why must transcription of ss R N A;-(antisense) strand occur during multiplication?

The antisense strand serves as a template for the synthesis of viral mRNA. Signup and view all the answers

Enzyme that produces DNA from a viral RNA genome is ____

reverse transcriptase Signup and view all the answers

If viral cancers are not contagious, how do they occur?

Viral cancers develop when viruses infect cells and interfere with normal cell growth, potentially leading to cancer. Signup and view all the answers

Distinguish latent virus infections from persistent viral infections

Latent viral infections involve the virus remaining dormant within the host without causing symptoms, while persistent viral infections involve the continuous presence of the virus within the host, often leading to long-term or chronic disease and typically, persistent viral infections are fatal. Signup and view all the answers

How do plant viruses enter plant cells?

Through wounds or with invasive parasites, such as insects. Signup and view all the answers

In what ways can PrP^Sc be transmitted?

All of the above Signup and view all the answers

Which of the following organisms are most closely related?

A and D Signup and view all the answers

Are any two the same species?

None are the same Signup and view all the answers

Which of these organisms are most closely related?

A and D Signup and view all the answers

The GC content of Micrococcus is 66–75 moles %, and of Staphylococcus, 30–40 moles %. According to this information, would you conclude that these two genera are closely related?

They are not related Signup and view all the answers

Which molecular biology techniques are commonly utilized for the rapid identification of unknown bacteria?

DNA Probe and PCR Signup and view all the answers

A 55-year-old veterinarian was admitted to a hospital with a 2-day history of fever, chest pain, and cough. Gram-positive cocci were detected in his sputum, and he was treated for lobar pneumonia with penicillin. The next day, another Gram stain of his sputum revealed gram-negative rods, and he was switched to ampicillin and gentamicin. A sputum culture showed biochemically inactive gram-negative rods identified as Pantoea (Enterobacter) agglomerans. After fluorescent-antibody staining and phage typing, Yersinia pestis was identified in the patient’s sputum and blood, and chloramphenicol and tetracycline were administered. The patient died 3 days after admission to the hospital. Tetracycline was given to his 220 contacts (hospital personnel, family, and co-workers). What disease did the patient have?

pneumonic plague caused by Yersinia pestis. Signup and view all the answers

A 55-year-old veterinarian was admitted to a hospital with a 2-day history of fever, chest pain, and cough. Gram-positive cocci were detected in his sputum, and he was treated for lobar pneumonia with penicillin. The next day, another Gram stain of his sputum revealed gram-negative rods, and he was switched to ampicillin and gentamicin. A sputum culture showed biochemically inactive gram-negative rods identified as Pantoea (Enterobacter) agglomerans. After fluorescent-antibody staining and phage typing, Yersinia pestis was identified in the patient’s sputum and blood, and chloramphenicol and tetracycline were administered. The patient died 3 days after admission to the hospital. Tetracycline was given to his 220 contacts (hospital personnel, family, and co-workers). Why were the 220 other people treated?

To stop the spread of the dangerous bacteria, the hospital gave medicine to everyone who had close contact with the patient to prevent them from getting sick too. Signup and view all the answers

Which Genus is characterized by its swarming ability?

Proteus. Signup and view all the answers

Where are heterocysts found?

Cyanobacteria Signup and view all the answers

What distinguishes Bdellovibrio from other in its class?

Its predatory behavior towards other gram-negative bacteria Signup and view all the answers

Hyphae involved in reproduction is called

reproductive or aerial hypha Signup and view all the answers

An asexual sport with a hyphal segment is called...

chlamydoconidium. Signup and view all the answers

Lichens are mutualistic combination of...

green alga (or a cyanobacterium) and a fungus. Signup and view all the answers

Algae that stores oil are called...

Diatoms Signup and view all the answers

The slime mold that exhibits cytoplasmic streaming.....

is a plasmodial slime mold. Signup and view all the answers

what cestode uses humans as a definitive host

Taenia saginata, the beef tapeworm. Signup and view all the answers

What distinguishes biological transmission from mechanical transmission?

Biological transmission involves the reproduction of the pathogen within the vector before transmission, while mechanical transmission does not. Signup and view all the answers

Of fungi, Sexual reproduction has not been observed in...

Microsporidia Signup and view all the answers

Fungi that produce basidiospores include

Basidiomycota, also known as club fungi Signup and view all the answers

Which is an example of chemoheterotrophic algae?

Oomycota (water molds) Signup and view all the answers

Alexandrium (red tide) has been called a plant, protist, protozoan, and alga in the past. Now it’s in the SAR clade, along with Plasmodium and Paramecium. Are all SAR members photosynthetic?

Only some members of the SAR clade are photosynthetic. Signup and view all the answers

It has characteristics of both plants and animals. Signup and view all the answers

Which bacterial classes belong to the Proteobacteria phylum?

Alpha, Beta, Gamma, Delta, and Epsilonproteobacteria Signup and view all the answers

Which uses reduced sulfur compounds as an electron donor?

Green and purple sulfur bacteria use reduced sulfur compounds as an electron donor Signup and view all the answers

How can some prokaryotes grow larger than normal bacterial sizes?

They undergo filamentous growth without cell division. Signup and view all the answers

Study Notes

Introduction

The science of taxonomy refers to the practice of describing, naming, and classifying various forms of organisms, including plants, animals, fungi, bacteria, and protists. Over time, the study has evolved, leading to significant changes in classification systems. With advancements in technology and scientific research, taxonomy has seen numerous improvements and adjustments in its methodologies. This article explores the Linnaean classification system and its transformation into modern classification systems, significant contributions in taxonomy, and recent advancements in the field.

The Linnaean Classification System

Carl Linnaeus is considered the father of modern taxonomy with his development of a hierarchical system for classifying organisms based on shared characteristics. This system was crucial in providing a consistent way to identify and categorize living beings, ultimately leading to better understanding of their relationships and evolutionary history.

Subdivisions of the Animal Kingdom (Animalia)

The Linnaean system divides the animal kingdom into several subdivisions or phyla:

Protista: Organisms that are neither plants nor animals; this group includes algae, protozoans, and slime molds.
Fungi: Non-motile multicellular eukaryotes including yeast, mushrooms, bracket fungi, rusts, smuts, parasites such as powdery mildews, and water molds.
Plants (Viridiplantae): Multicellular autotrophs able to produce their own food via photosynthesis.
Animalia: A diverse group of multicellular, eukaryotic life forms whose cells lack cell walls and contain membrane-bound organelles.

Modern Classification Systems

Since Linnaeus' time, various modifications have been made to the original classification scheme, primarily due to advances in molecular biology and genetic studies. Some key changes include:

Kingdom Protista: Replaced with separate domains Bacteria and Archaea to account for prokaryotic differences from Eukarya.
Phylum Chordata: Split to accommodate placental mammals, marsupials, monotremes, birds, reptiles, amphibians, fish, and lancelets.
Class Mammalia: Expanded to include Eutheria (placental mammals), Metatheria (marsupial mammals), and Monotremata (egg-laying mammals).
Order Primates: Further divided into superfamilies, families, and subfamilies.

Key Scientists in Taxonomy

Some notable individuals who contributed significantly to the field of taxonomy include:

Caroline Herschel: Known for discovering eight comets, she also cataloged over 2,500 stars.
Louisa Swainson: The first woman to describe a new species of bird and the only female taxonomic artist for the British Museum's collection.
Alfred Russel Wallace: Co-discoverer of the theory of evolution by natural selection with Charles Darwin.

Significant Contributions in Taxonomy

Some significant contributions to taxonomy include:

Biogeography: Studying the distribution of species across the globe.
Systematics: Analyzing relationships and classifying organisms based on shared traits.
Phylogenetics: Inferring evolutionary relationships and constructing evolutionary trees from genetic data.
Ethnobotany: Studying plants used by different cultures or ethnic groups for food, medicine, shelter, etc..

Taxonomy Advancements in Recent Years

Recent advancements in technology have greatly impacted taxonomy:

DNA Sequencing: Allows scientists to analyze genetic material from individuals, populations, or entire species.
Computational Tools: Software programs like BOLD, iBOL, and Cytochrome PCR can help with identification and classification.
Machine Learning Algorithms: These algorithms can assist in identifying relationships between taxa based on large datasets.

In summary, taxonomy has seen significant changes over time, transitioning from Linneaus' hierarchical system to modern classifications influenced by molecular biology and genetic studies. Key contributions include the work of notable figures such as Caroline Herschel and Alfred Russel Wallace, while recent advancements rely heavily on technological tools like DNA sequencing and computational algorithms to better understand organisms and their relationships.

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