BSCC 1011 Biology 2 Test 2 Review

What are the 2 unifying characteristics of Diatoms?

Diatoms are photosynthetic and have unique double tests (shells) made of silica.

After a virus enters the host cell's transcription and translation processes, what 3 sets of genes are expressed and what do they produce? After all 3 sets of genes are expressed, what is produced?

Early genes produce viral proteins, middle genes replicate viral nucleic acids (DNA or RNA) and produce capsid proteins, while late genes produce proteins for assembly and release. After all three sets of genes are expressed, the end result produced is assembly and release of viruses.

True or false: There are only a few thousand types of viruses and they can infect all organisms. Explain your answer.

False. Every single cell type has atleast one virus after it, therefore there are trillions of viruses.

True or false: fungi are mostly multicellular, mostly aerobic, mostly terrestrial, photosynthesizers. Explain your answer.

False. Fungi are not photosynthesizers.

True or false: all protists are eukaryotic, single-celled, and microscopic. Explain your answer. What makes an organism a protist?

False. Most protists are unicellular but some are multicellular organisms. Protists are not fungi, plants, or animals. They are the most diverse of the four eukaryotic kingdoms.

True or false: all protists do both asexual and sexual reproduction. Explain your answer.

False. Not all protists reproduce sexually.

What are the two shapes are viruses? What is binal symmetry? What is polymorphic?

Helical (rod-shaped, most common) and isometric (spiral); can also be icosahedral (spherical). Final symmetry refers to symmetry that contains both icosahedral (spherical) and helical portions. Polymorphic refers to enveloped viruses with no distinct symmetry.

What is the common name for Deuteromycetes? Why is it not a phylum?

Imperfect fungi. It is the only polyphyletic group and have no evidence of sexual reproduction.

If most prokaryotes are unicellular, than what are biofilms and colonies?

A biofilm refers to communities of many species of bacteria. A colony refers to a single species of bacteria attached to each other.

What is a capsid? What is an envelope? What is a naked virus?

A capsid is a protein sheath around nucleic acids that may contain specialized enzymes. An envelope is present in some viruses (not found in naked viruses) and is formed around capsid with viral proteins and host's lipids. A naked virus refers to a virus without an envelope.

What are the two types of transformation? What are the differences between the two types of transformation?

Natural transformation occurs in many bacterial species (streptococcus/Griffin exp.); DNA released from a dead cell is picked up by live cell and incorporated by homologous recombination.

List 5 non-sexually-transmitted human diseases caused by bacteria. List 3 sexually transmitted diseases caused by bacteria.

Non-sexually transmitted: Tuberculosis, leprosy, tetanus, dental caries, whooping cough. Sexually transmitted: Gonorrhea, chlamydia, syphilis.

What are stromatolites and what type of prokaryote makes them? What are biomarkers?

Stromatolites are created by cyanobacteria (blue-green algae) that trap mineral deposits and form rocks (layered rock). Biomarkers are organic molecules of biological origin whose presence is indicative of some phenomenon (disease, infection, etc).

What are internal membranes?

Structures that encase organelles and control the exchange of essential cell components for respiration; found in eukaryotes.

True or false: viruses can cause diseases, lead to cancer, and cause major agricultural and forestry loses.

True.

True or false: fungal spores can be produced through asexual and sexual reproduction, give rise to new fungi individuals, and are dispersed by wind, insects, and animals. Explain your answer.

True. Spores are the most common means of reproduction among fungi. They form through asexual/sexual reproduction; germination gives rise to new fungi through dispersion.

Why do viruses require a host to reproduce?

Viruses need a host in order to replicate. They lack the enzymes and ribosomes needed for transcription and translation, therefore viral genes are translated into proteins by the host so the virus can replicate.

Can viruses be beneficial? Briefly explain.

Yes. Viruses can cause genetic alteration of a cell's genome with the introduction of foreign DNA. They can be used to treat genetic illnesses and help fight cancer.

What are the 4 unifying characteristics of Chytridiomycetes?

1. Aquatic, flagellated fungi 2. No dikaryon stage 3. Diploid asexual reproductive cycle 4. Have zoospores (motile spores)

Name 3 groups of protists that do not fit into the 7 monophyletic groups of protists.

1.

Describe the 5 steps of the lytic cycle.

1. Attachment: tail fiber contacts host bacterial cell wall. 2. Penetration/Injection: tail contracts, passes through opening in base plate piercing bacterial cell wall, and injecting contents into cytoplasm. 3. Synthesis: viral genome and proteins are replicated. 4. Assembly: viral components are assembled and put together. 5. Release: virus exits.

What are the 6 groups of fungi? List the phylum and common name. Which group is a polyphyletic group?

1. Phylum Chytridiomycota "chytrids" (aquatic) 2. Phylum Zygomycota 3. Phylum Glomeromycota 4. Phylum Ascomycota "sac fungi" 5. Phylum Basidiomycota "club fungi" 6. Phylum Deuteromycetes "imperfect fungi" (also polyphyletic)

What is a bacteriophage? What type of cells do bacteriophages infect?

A bacteriophage is a virus that infects bacteria.

What are the 7 major groups in the Kingdom Protista?

1. Metamonada 2. Euglenozoa 3. Alveolata 4. Stramenopila 5. Rhodophyta 6. Chlorophyta 7. Chanoflagellida

What are the 4 unifying characteristics of Euglenozoa? Give examples of Euglenozoa.

1. No sign of sexual reproduction 2. Nuclear envelope remains through mitosis 3. Pellicle 4. Anterior flagella Examples: Euglena, trypanosomes

What are the 2 unifying characteristics of Dinoflagellates? Explain how Dinoflagellates are responsible for red tide.

1. Two unequal flagella (steering/repulsion) 2. DNA is not complexed with hastened (trait seem in 99% prokaryotes) Dinoflagellates are responsible for red tide through algal blooms where species causing red tides have the ability to produce toxins as metabolic by-products.

What is a chemolithotroph? What is nitrification? Besides nitrogen, what are some other inorganic molecules used by chemolithotrophs?

A chemolithotroph obtains energy from chemical bonds of inorganic molecules to synthesize carbohydrates (eukaryotes can't). Nitrification is the process by which bacteria (in soil or water) oxidize ammonia and form nitrite/nitrate. Other inorganic molecules besides nitrogen include sulfur, hydrogen gas, etc.

What is a cyst? What purpose does it serve? Do all protists produce cysts?

A cyst is a dormant cell with a resistant outer covering. It is used for disease transmission. No, not all protists make cysts.

What is an emerging disease?

A disease that has appeared in a population for the first time, or may have existed previously but is rapidly increasing in geographic area. It starts in one host then extends the host range.

What does the Gram stain test in bacteria? What does it mean if a bacteria is Gram + or Gram -?

A gram stain tests how thick or thin a cell wall is in bacteria. Gram (+) bacteria have a thick cell wall with peptidoglycan that stains violet, whereas gram (-) bacteria have a thin cell wall, but have a second outer layer of lipopolysaccharides that stains pink.

What is a heterotroph? What is the difference between a photoheterotroph and a chemoheterotroph?

A heterotroph is an organism that obtains carbon from organic carbon molecules. A photoheterotroph uses light as an energy source but carbon from organic molecules, whereas a chemoheterotroph obtains carbon and energy from organic molecules.

What is an Hfr cell? What is integration and excision? What is an F' plasmid?

A hfr (high frequency recombination) cell is a cell with F plasmid integrated into chromosome. Integration is the process where the F plasmid may combine into bacterial chromosome. F' plasmid refers to an inaccurate excision so that the F plasmid picked up chromosomal DNA.

Use the words (phage conversion, lysogeny, lysogen, prophage) to fill in the following sentences.

A host cell becomes a prophage when viral DNA is integrated into the host genome in a process called lysogeny. The integrated viral DNA segment is called lysogen. When the host's phenotype if altered by the integrated viral DNA segment, the process is called phage conversion.

What does it mean when a virus is latent? Will it ever be active again?

A latent virus refers to an inactive, dormant virus. It can be latent for years inside a host and can become active again.

Euglena have a pellicle, contractile vacuole, and stigma. What is the role of each structure?

A pellicle refers to flexible, tough, interlocking-protein strips in plasma membrane. Contractile vacuoles collect excess water. Stigma is a structure that locates light for photosynthesis.

What are phototrophs, heterotrophic phagotrophs, heterotrophic osmotrophs, and mixotrophs?

A phototroph is an organism that is photosynthetic. A heterotrophic phagotroph is an organism that obtains energy from organic molecules of others by injecting particulate food matter through phagosomes (vesicles). A heterotrophic osmotroph is an organism that obtains energy by ingesting soluble food matter. Mixotrophs are organisms which are both phototrophic and heterotrophic.

What is a prion? What group of diseases does it cause?

A prion is a proteinaceous, infectious particle that causes transmissible spongiform encephalopathies (TSE), such as Mad Cow disease, Scrapie, and Creutzfeldt-Jacob disease.

What is an s-layer? What is a capsule? What are endospores?

A s-layer is the surface layer of a rigid protein/glycoprotein outside cell wall layer in some bacteria and archaea. A capsule is a gelatinous layer that surrounds the cell wall found in some bacteria. Endospores are thick-coated, highly resistant cells produced by some bacteria when exposed to harsh conditions.

What is a virus? What is a virion?

A virus is an obligate intracellular parasite made up of genetic material (DNA or RNA) enclosed in protein that can invade living cells. A virion is a single viral cell enclosed in protein.

Circle the following fungi groups which have asexual reproduction: Chytridiomycetes, Zygomycetes, Glomeromycetes, Ascomycetes, Basidiomycetes, Deuteromycetes

All.

What is alternation of generations (also found in algae, foraminifera, and plants)? Are most fungal cells haploid (N) or diploid (2N)?

Alternation of genes refers to the occurrence of both a multicellular diploid organism (sporophyte) and a haploid organism (gametophyte). Fungal cells are mostly diploid.

What are the 2 unifying characteristics of amoebas? What are the two groups of amoebas?

Amoebas have pseudopodia (pseudopods) and experience movement through cytoplasmic streaming. The two groups are rhizopoda and actinopoda.

What is an autotroph? What is a photoautotroph? What is the difference between an oxygenic and anoxygenic photoautotroph?

An autotroph is an organism that obtains carbon from inorganic carbon dioxide. A photoautotroph is an organism that carries out photosynthesis to synthesize carbohydrates. Oxygenic photoautotrophs produce the by-product oxygen using chlorophyll, whereas an oxygenic photoautotrophs are organisms that produce the by-product sulfur/sulfate using bcateriophyll.

Circling the following metabolism types which are only found in prokaryotes: oxygenic photoautotroph, anoxygenic photoautotroph, chemolithotroph, photoheterotroph, chemoheterotroph

Anoxygenic photoautotroph and chemolithotroph.

What are the 2 unifying characteristics of Ascomycetes? Why are yeasts of Ascomycetes a unique fungal group (hint: cells)?

Ascomycetes contain an ascus (sac-shaped, sexual spore-producing structure) and ascocarb (cup/morel structure of dikaryon stage). Yeasts are the only unicellular fungi that reproduce asexually through budding or binary fission.

What are ascospores, conidia, and conidiophores of Ascomycetes?

Ascospores are sexual-walled, eight haploid nuclei produced within ascus meiosis and mitosis. Conidium (conidia) are asexual spores. Conidiophores are asexual, spore-producing structures.

What are the 3 shapes of prokaryotes?

Bacillus (straight, rod-shaped), coccus (spherical), and spirillum (long, helical-shaped). Prokaryotes can also be spirochetes (corkscrew-shaped).

Compare and contrast DNA replication and gene expression of Bacteria and Archaea.

Bacteria have simple DNA replication whereas archaea DNA replication is more similar to that of eukaryotes. Bacteria have only one RNA polymerase, whereas archaea have multiple RNA polymerases. Archaea transcription/translation is also similar to eukaryotes due to presence of introns.

Compare and contrast the plasma membranes and cell walls of Bacteria and Archaea.

Bacteria lipids are unbranched, whereas archaea lipids are branched. In both, fatty acid tails are connected to glycerol by ester linkages. Bacteria also have peptidoglycan in their cell well (gram positive) while archaea lack peptidoglycan, but some have pseudomurein which is similar to peptidoglycan. In both, the cell wall has the same function and maintains shape, protecting the cell from swelling and rupturing.

What are basidiocarps of Basidiomycetes?

Basidiocarps refer to mushrooms dikaryon stage. They are sexual spores formed entirely of secondary mycelium.

What are the 2 unifying characteristics of Basidiomycetes?

Basidiomycetes contain basidium (club-shaped, sexual spore-producing structure) and basidia are on basidiocarps (mushrooms=dikaryon stage).

What are binary fission, schizogony, and budding?

Binary fission is a type of asexual reproduction that involves the splitting of a parent cell into two equal parts. Schizogony is an asexual reproduction characterized by multiple fission. Budding is an asexual reproduction in which a new organism develops from an outgrowth of a cell/body region, leading to separation from the original into two individuals.

Circle the following methods by which you can contract HIV: blood, shaking hands, ear wax, semen, breast milk, urine, feces, sharing a cup, sneezing, saliva, coughing, vaginal secretions, oral sex, tears, anal sex, sweat, kissing, vaginal sex, unsterile hypodermic needles, toilet seat, swimming pool, mosquito.

Blood, semen, breast milk, vaginal secretions, oral sex, anal sex, vaginal sex, unsterile hypodermic needles.

What is the 1 unifying characteristic of Chlorophyta? What is the common name of Chlorophyta? Why will Phylum Chlorophyta not be considered protists soon?

Chlorophylls. Chlorophyta is commonly known as green algae. It will be moving to kingdom virdiplantae.

Circle the following fungi groups which have sexual reproduction: Chytridiomycetes, Zygomycetes, Glomeromycetes, Ascomycetes, Basidiomycetes, Deuteromycetes

Chytridiomycetes, zygomycetes, ascomycetes, and basidiomycetes.

What are the 3 unifying characteristics of Ciliates? Give an example of Ciliates.

Cilia, pellicle, two nuclei (macro/micronucleus). Examples include: Paramecium, stentor, vorticella.

Conjugation is a type of horizontal gene transfer. In your own words, describe how conjugation occurs.

Conjugation is the direct transfer of DNA from one bacterial cell to the next. It occurs with an F plasmid. Strains of bacteria containing the plasmid are F+ and those without it are F-. F+ (donor) cell produces a plus to form a conjugation bridge, resulting in 2 F+ cells. Genetic material is transferred.

What is the 1 unifying characteristic of Aveolata? Give examples of Aveolata.

Contain alveoli: flattened vesicles that function like golgi bodies for transport. Examples include: gymnopodium, Toxoplasma gondii, paramecium, etc.

What is the 1 unifying characteristic of Choanoflagellates?

Contain single emergent flagellum surrounded by a funnel-shaped contractile collar to deed on bacteria (similar to sponges).

What form is prokaryotic DNA stored in? Where in the cell is it? What are plasmids?

DNA is single, circular, double-stranded, stored in the chromosome. Plasmids refer to small, circular DNA molecules that replicate independently.

Viruses are classified by their genome. Compare and contrast the 3 types of viruses.

DNA viruses are the most stable (due to slow mutation), followed by retroviruses, and RNA viruses. DNA viruses are double-stranded, whereas RNA viruses are single-stranded. DNA replication occurs in the nucleus of a cell while RNA replication occurs in the cytoplasm of the cell. All three viruses contain a core of nucleic acid surrounded by protein and are also viral structures.

What 2 domains and what 2 kingdoms are prokaryotic?

Domains/kingdoms bacteria and archaea.

Fungi are heterotrophs that can break down plant lignin and cellulose through external digestion. What is external digestion? What is a saprobe?

External digestion is a process in which heterotrophs obtain food by secreting digestive enzymes and absorbing organic molecules (absorptive heterotroph). A saprobe refers to organisms that absorb organic matter from a non-living source.

What are F plasmid, F+ cell, F- cell, F pilus, and conjugation bridge?

F plasmid is the fertility factor; a plasmid that enables the transfer of DNA from donor to recipient cell. F+ cell is a donor cell that contains the plasmid. F- cells are recipient cells that do not contain the plasmid. The F plus is an extension of the cell wall that connects F+ to F- cell. A conjugation bridge is the connection formed between F+ and F- by attachment of F pilus.

What are the 2 unifying characteristics of Diplomonads and Parabasalids? Give examples of Diplomonads and Parabasalids.

Flagella and lack mitochondria. An example of a diplomonad is Giardia intestinalis. An example of a parabasalid is Trichomonas vaginalis.

What are flagella? What are pili?

Flagella are long, helical structures that allow the cell to move. Pili are small, hair-like structures that aid in attachment and conjugation, found in gram-negative bacteria,

What is the 1 unifying characteristic of Stramenopila? Give examples of Stramenopiles.

Flagella with fine hairs. Examples include brown algae (phaeopyta) and Laminaria (kelp).

List 3 types of locomotion in protists.

Flagellum, cilia, and pseudopodia (pseudopods).

What are the 2 unifying characteristics of Foraminifera?

Foraminifera contain tests and have thin pseudopodia emerge through pores.

Fill in the following sentences with the words: chitin, coenocytic, septa, hyphae, rhizoid, mycelia.

Fungi have a filamentous body form with filaments called hyphae which form masses called mycelia. Some are divided by cross walls called septa; others are continuous between cells, called coenocytic, which allows for cytoplasmic streaming. Like arthropod skeletons, fungi have chitin in their cells walls to give them support and structure. Root-like structures, called rhizoids, allow fungi to anchor on to the ground, rocks, or plants.

Describe 2 ways fungal mitosis differs from most eukaryotic mitosis.

Fungi undergo nuclear mitosis where the nucleus does not break down at the start of mitosis. Fungal mitosis also differs because a spindle apparatus forms within the nucleus.

What are the two types of transduction? What are the differences between the two types of transduction?

Generalized transduction is the process in which bacterial DNA is transferred (virtually every gene) to another cell via bacteriophage; occurs in lytic cycle. Specialized transduction is the process in which a restricted set of bacterial genes is transferred (only few genes); occurs when prophage excises imprecisely from chromosome; occurs by accident in lysogenic cycle.

What are the 2 unifying characteristics of Glomeromycetes?

Glomeromycetes lack septa between hyphae and show no evidence of sexual reproduction.

How does HIV attack the body? Does HIV kill you? Explain your answer.

HIV targets and kills CD4+ (T-Helper) cells which initiate immune response. As a result, the host ultimately dies from opportunistic infections because they are immunocompromised.

List at least 5 diseases from viruses.

HIV, Influenza, Ebola, HPV, Leukemia.

What does HIV stand for? What does AIDS stand for? Which is the virus and which is the disease caused by the virus? What type of virus is it?

Human immunodeficiency virus (HIV). It is a retrovirus that causes acquired immune deficiency syndrome (AIDS).

Brown algae (Phaeophyta, Stramenopila), red algae (Rhodophyta), green algae (Chlorophyta), and forams (Foraminifera) all have alternation of generations.

In alternation of generations, the gametophyte is haploid and the sporophyte is diploid.

What is the difference between monokaryotic and dikaryotic? What is the difference between homokaryotic and heterokaryotic?

Monokaryotic refers to one nucleus in the hypha, haploid or diploid. Dikaryotic refers to two haploid nuclei which coexist in hypha before fusing to form diploid nucleus. Homokaryotic refers to hypha whose nuclei are genetically similar to one another. Heterkaryotic refers to dikaryotic hypha with nuclei from genetically different individuals (different mating types).

Are viruses alive? Give 3 reasons to support your answer.

No. Viruses cannot reproduce on their own, cannot metabolize on their own to acquire and/or use energy, and have no cellular structure.

Define obligate symbiosis and facultative symbiosis. What is the difference between symbiotic relationships of pathogens, parasites, commensalisms, and mutualisms?

Obligate symbiosis refers to a partnership that is essential for fungus survival. Facultative symbiosis refers to a partnership that is nonessential for fungal survival. Pathogens are parasitic and benefit at the expense of the host. Commensalism refers to a partnership in which one organism benefits and the other is unharmed. Mutualism refers to a partnership where both organisms benefit.

Are protists monophyletic, paraphyletic, or polyphyletic? What places a protist in the Kingdom Protista?

Paraphyletic. Protists are the most diverse of the four eukaryotic kingdoms. They are not fungi, plants, or animals; mostly unicellular.

Describe 3 ways prokaryotes are beneficial.

Prokaryotes may live in symbiotic relationships with eukaryotes (nitrogen-fixing bacteria). They are crucial to chemical cycles (decomposers, photosynthesizes, nitrogen-fixers) and are used in genetic engineering.

Prokaryotes do not have sexual reproduction, so how is reproduction accomplished? Genetic recombination is not accomplished through reproduction, but instead through mutations and horizontal gene transfer. Define horizontal gene transfer.

Reproduction is accomplished through binary fission, asexual reproduction where replicated chromosomes divide into two nearly equal daughter cells. Horizontal gene transfer is the transfer of genes from one genome to another.

What is reverse transcriptase? Which type of virus does reverse transcriptase?

Reverse transcriptase is an enzyme used to generate complementary DNA from an RNA template; aka process of reverse transcription. Retroviruses use reverse transcriptase to convert genes into DNA.

What are the 2 unifying characteristics of Rhodophyta? What is the common name of Rhodophyte?

Rhodophyta lack flagella and photosynthetic pigment phycobilin (phycoerythrin); also commonly known as red algae.

What are the 2 unifying characteristics of slime molds? What are the two groups of slime molds?

Slime molds contain oozing masses (growth form) and form spores when food/moisture is scarce to last for years (environmental). The two groups of slime molds are plasmodial and cellular.

What is the difference between a sporophyte and gametophyte? What do each of them give rise to? What is the difference between a gametangium and sporangium?

Sporophyte is diploid (2N); produces spores from sporangium for asexual reproduction. Gametophyte is haploid (N); produces gametes from gametangium for sexual reproduction.

What are tests and pseudopodia of Foraminifera?

Tests are pore-studded, calcium-carbonate shells. Pseudopodia refers to a thin extension that emerges through pores in tests; used for swimming and feeding.

Fungi can reproduce sexually with a compatible mating type, asexually, or parasexually. What is the dikaryon stage (N+N) of sexual reproduction? Define plasmogamy and karyogamy.

The dikaryon stage (N+N) refers to the process where cells of two different hyphae fuse and the nuclei of each cell remain distinct within the new hyphae. Plasmogamy refers to the fusion of two hyphae's cytoplasm. Karyogamy refers to the fusion of two haploid nuclei.

What is induction?

The process by which a virus switches from the lysogenic cycle to the lytic cycle, where the prophage exits the host chromosome.

What is the host range of a virus? What is tissue tropism?

The host range refers to cells that are suitable for a virus. Tissue tropism refers to the types of cells that can be recognized by that virus to gain access to the host.

What is the lysogenic cycle? What is another name for a lysogenic virus?

The lysogenic cycle is another reproductive process of a bacteriophage that integrates viral genomes into the host's genome. It is termed temperate.

What is the lytic cycle? What is another name for a lytic virus?

The lytic cycle is a reproductive cycle that utilizes host cell's machinery to replicate viral genome and kill the host cell. It is also termed virulent.

What is unique about the dispersion method of haploid and diploid zoospores of Chytridiomycetes?

The zoospores are flagellated haploid and diploid motile spores.

What are viroids? What do they cause?

Tiny, naked molecules of circular RNA that cause disease in plants. It is unclear how they cause disease.

Transduction is a type of horizontal gene transfer. In your own words, describe how transduction occurs.

Transduction is the process in which bacteriophages bring new genetic material. There are two types of transduction - generalized and specialized. In generalized, the phage first adheres to cell, viruses package DNA with accidental viral DNA, and transfer to host. Specialized transductions occurs through the lysogenic cycle by accident.

Transformation is a type of horizontal gene transfer. In your own words, describe how transformation occurs.

Transformation is the process by which bacterial cells take up naked DNA molecules in the environment. If foreign DNA has an origin of replication recognized by the host's DNA polymerases, the bacteria will replicate the foreign DNA along with their own.

What is the 1 unifying characteristic of Zygomycetes?

Zygomycetes lack septa between hyphae except when forming sporangia or gametangia.

Circle the following fungi groups which have a dikaryon stage: Chytridiomycetes, Zygomycetes, Glomeromycetes, Ascomycetes, Basidiomycetes, Deuteromycetes

Zygomycetes, Ascomycetes, and Basidiomycetes.

What are zygosporangia, zygospores, and sporangiophores of Zygomycetes?

Zygosporangia refers to dikaryotic stage with spore-producing structures; temporarily dormant, but gametangia fuse (sexual reproduction begins). Zygospores are sexual spores developed from zygosporangia. Sporangiophores are clumps of erect stalks produced by hyphae.