Bacteria and Fungi Flashcards

Question

Dikaryotic

Answer 1

two haploid nuclei from each parent”, a transition stage between haplontic and diplontic where plasmogamy (fusion of cytoplasm's from parental mycelia) has occurred, but karyogamy (fusion of nuclei, thus completing fertilization) has not

Answer 2

fusion of nuclei, thus completing fertilization

Answer 3

produces the zygote (zygospore) a sturdy multinucleate structure in which karyogamy and meiosis occur produced by plasmogamy represents the zygote (2n) stage in the life cycle, it is not a zygote in the usual sense (that is, a cell with one diploid nucleus) a zygosporangium is a multinucleate structure, first heterokaryotic with many haploid nuclei from the two parents, then with many diploid nuclei after karyogamy.

Answer 4

diploid nuclei produced by karogamy in zygomycetes

Answer 5

the fruiting body of a sac fungus | contain spore forming asci

Answer 6

a saclike spore capsule located at the tip of a dikaryotic hypha of a sac of fungi

Answer 7

(sexual spore) are produced in dikaryotic asci contained within ascocarps

Answer 8

are produced in structures called conidiophores

Answer 9

fruiting body of a dikaryotic mycelium of a club fungus

Answer 10

sexual spore) are produced in dikaryotic basidia contained within basidiocarps

Answer 11

(endomycorrhizal) -> Have branched hyphae called arbuscules that penetrate plant host cells to exchange nutrient

Answer 12

Ectomycorrhizal fungi form sheaths of hyphae over the surface of a root and typically grow into the extracellular spaces of the root cortex Arbuscular mycorrhizal fungi (from the Latin arbor, tree) extend branching hyphae through the root cell wall and into tubes formed by invagination (pushing inward) of the root cell plasma membrane

Answer 13

Fungi reproduce via spores, which can be produced sexually (meiospores) or asexually (mitospores)

Answer 14

Phylogenetics has suggested fungi originated from a flagellated unicellular aquatic protist ancestor * Animals, fungi, and protistan relatives form a monophyletic clade called the Opisthokonts (opistho = flagellal position) * Fungi more related to single-celled protistan relatives (nucleariids) than animals proper Nucleariids consist of amoebas that feed on algae and bacteria DNA evidence suggests that animals are more related to another group of protists (choanoflagellates) than to either fungi or nucleariids We can conclude then that multicellularity evolved independently in animals and fungi

Answer 15

``` Chytridiomycetes Glomeromycetes Zygomycetes Ascomycetes Basidiomycetes ```

Answer 16

Phylum: Chytridiomycota (mycota- phylum level) basal fungi ~1000 species Found in lakes and soils, hydrothermal vents Most are decomposers(pollen grain), but some are pathogenic Batrachochytrium salamandrivorans attacks amphibians and has decimated their populations ) some chytrids are mutualists (Live in the guts of sheep to help break down plant matter) All chytrids have flagellated zoospores (spores that move) Have cells walls of chitin

Answer 17

moulds” ~1000 species Found in soils and air, Most are fast-growing moulds, microscopic Rizopus stolonifer is a common bread mould Hyphae are coenocytic with septa only in reproductive hyphae Sporangia -> produces spores Zygosporangia -> produces the zygote (zygospore) dominant stage; Haploid

Answer 18

“mycorrhizae” Phylum: Glomeromycota (formerly Zygomycota) ~200 species Found in soils and air, Most are arbuscular mycorrhizal About 80% plants associate with Glomeromycota Hyphae are coenocytic Spores look similar to zygospores Similar life cycle to zygomycota Molecular evidence however has discerned that the Glomeromycota is its own monophyletic clade dominant stage: haploid

Answer 19

“sac fungi” Phylum:Ascomycota ~65,000 species Found in marine, freshwater, and terrestrial habitats Can be unicellular yeasts, or multi- cellular fungi Saprotrophs, pathogens, mutualists, mycorrhizal Fruiting body: ascocarps Produces ascospores (sexual) in asci (sing. ascus) Hyphae are septate Dominant stage; haploid

Answer 20

club fungi” Phylum: Basidiomycota ~30,000 species Contain puffballs, “mushrooms”, shelf fungi Saprotrophs, pathogens (rusts and smuts), mutualists, mycorrhizal Fruiting body: basidiocarps containing “gills” Produces basidiospores (sexual) in dikaryotic basidia (sing. basidium) contained on the gills Hyphae are septate FYI: When conditions are optimal for reproduction, basidiocarps can establish within hours dominant stage; dikaryotic

Answer 21

Bacteria and Archaea

Answer 22

Tailing ponds from mining Super salty deserts and lakes (ie Great Salt Lake in Utah) Under glaciers in the Arctic and Antarctic Blood falls in Antarctica Thermophilic bacteria in yellowstone Thermal vents surrounding volcanic features Human gut(very acidic!)

Answer 23

Can use metagenomics to identify prokaryotic species in soil and even the human gut (called the microbiome) The study of metagenomes

Answer 24

0.5 - 5μm in size (exception Thiomargarita namibiensis is 750 μm across!) Unicellular Lacks membrane-bound organelles (contains a plasmid (contains the DNA) within the nucleoid,) Come in three main shapes Have a cell wall of peptidoglycan (bacteria) Cell wall is surrounded by a capsule or slimy covering Some prokaryotes also have fimbriae Prokaryotes can move within the environments Can use a flagellum Reproduce via binary fission

Answer 25

Bacterial cell walls are composed of peptidoglycan(Structural carbohydrate composed of sugars cross-linked with short polypeptides) • Archaeal cells walls are composed of other complex sugars and proteins but lack peptidoglycan

Answer 26

slimy covering surrounding cell wall Composed of polysaccharides and/ or protein Allows adherence to substrata or each other within the colony Protects against desiccation and bacteriophages(viruses)

Answer 27

Hairlike projections to anchor to hosts or substrata(or to each other)

Answer 28

uses crystal violet dye and iodine, and alcohol rinse, and a final stain of red dye

Answer 29

Chemotaxis-->response to a chemical Positive chemotaxis -> towards a chemical Negative chemotaxis -> away from a chemical flagellum

Answer 30

Much thinner than eukaryotic flagella and not covered with an extension of the plasma membrane different in their molecular composition and their mechanism of propulsion Bacteria and archaea flagella differ in protein composition but are similar in size and rotation mechanism,

Answer 31

The structure of the flagella across the 3 domains suggest they arose independently -> they are analogous structures!

Answer 32

binary fission Under optimal conditions can divide every 1-3 hours They don’t over divide because of space availability competition Nutrient and space availability (quorum sensing), self-poisoning, competition limits colony cell Colony of E.coli can divide in 20 mins They are small, they reproduce by binary fission, and they have short generation times

Answer 33

need O2 for cellular respiration

Answer 34

are poisoned by O2 Something else sulfate Acquire energy from fermentation or anaerobic respiration

Answer 35

in organic molecules other than oxygen accept electrons at the downhill end of the electron transport chain

Answer 36

use O2 when available but will carry out fermentation or anaerobic respiration when oxygen is absent

Answer 37

converting N2 to NH3 | some have mutualistic relationships with plants

Answer 38

a non membrane bounded region in a prokaryotic cell where the DNA is concentrated

Answer 39

a small circular double stranded DNA molecule

Answer 40

Prokaryotes generally have circular chromosomes whereas eukaryotes have linear chromosome in prokaryotes the chromosome is associated with many fewer proteins than are the chromosomes of eukaryotes prokaryotes lack a membrane-bounded nucleus; their chromosome is located in the nucleoid, a region of cytoplasm that is not enclosed by a membrane In addition to its single chromosome, a typical prokaryotic cell may also have much smaller rings of independently replicating DNA molecules called plasmids

Answer 41

Prokaryotes have diverse nutritional adaptations allowing them to inhabit diversely harsh environments Obligate aerobes Obligate anaerobes Facultative anaerobes nitrogen fixation -

Answer 42

Have specialized cells called heterocysts in photosynthetic prokaryotes to carry out N-fixation Nitrogen fixers are often poisoned by oxygen so they have to contain the nitrogen fixing enzyme within a special cell the heterocyst and that is a anaerobic environment just within that specialized cell Allows them to do photosynthesis and nitrogen fixation

Answer 43

the community of microorganisms that live in or on the body

Answer 44

Diverse nutritional modes allow diverse bacteria to inhabit the human gut (called our microbiome) (if you eat a lot of carbs your microbiome is going to be different from a person who eats a lot of veggies) Contain ~10 trillion bacteria in our guts Are mutualists -> break down food that we cannot We can absorb the nutrients they break down in exchange for our blood cells producing anti-microbial compounds to reduce competition and keep only the “good” bacteria We consume probiotics to help establish healthy populations of “good” bacteria

Answer 45

Archaea are prokaryotes that inhabit some of the harshest environments (we call these extremophiles) (difference in cell wall composition allow them to do this) Thermophile will have different cell wall composition then acidophile –species specific

Answer 46

Archaea are prokaryotes that inhabit some of the harshest environments (we call these extremophiles) (difference in cell wall composition allow them to do this) Thermophile will have different cell wall composition then acidophile –species specific

Answer 47

Bacteria are basal archaea are more closely related to domain eukarya than they are bacteria

Answer 48

There are ~ 100,000 species of identified fungi Could be up to 1.5 million species! Fungi can be single-celled(yeasts), microscopic(molds), filamentous or macroscopic(mushrooms) Found in all habitats, both terrestrial and aquatic Fungi are the nutrient recyclers within the ecosystem, breaking down decaying organic matter can be saprotrophs (decomposers), parasites, pathogens, mutualists

Answer 49

•Like animals, fungi are heterotrophs Animals > ingestion Fungi > absorption

Answer 50

Secrete hydrolytic enzymes into the environment through threadlike hyphae which breaks down nutrients Secrete enzymes to penetrate cell walls of host cells, allowing fungi to get nutrients through parasitism and infection Can break down a variety of compounds, including lignin(wood) and cellulose (which animals cannot digest)

Answer 51

Single-celled fungus that reproduces asexually by binary fission or by the pinching of small buds off a parent cell. Some species exhibit cell fusion between different mating types.

Answer 52

are multicellular or single cells ( yeasts)

Answer 53

Hyphae (sing. Hypha) - tiny tubular filaments surrounding the plasma membrane (between the cells and substrate absorbing the nutrients, fingers and arms) Mycelium > a mass of hyphae that maximizes SA:volume ratio(body) Fruiting body > reproductive structure (mushroom we eat) Cell walls > composed of chitin (nitrogen containing polysaccharide)

Answer 54

One of many connected filaments that collectively make up the mycelium of a fungus.

Answer 55

The densely branched network of hyphae in a fungus | that infiltrates the material on which the fungus feeds

Answer 56

Septate (divided, allowing large macromolecules to pass between hyphal cells Coenocytic (lacking septa/no divisions) with a continuous cytoplasmic mass

Answer 57

are specialized fungi that form associations with plants Many mycorrhizal fungi look like regular “mushrooms” (Mushroom sitting under the tree that is the fruiting body reproductive structure all of the mycorrhizal part of the fungi is underground)

Answer 58

forms sheaths of hyphae around plants roots(form hyphae along outside of plant root, become extension of roots absorbing nutrients in exchange for photosynthates )

Answer 59

Mycorrhizal mycelia increase the surface area and efficiency of absorbing phosphate ions and other minerals in the soil • More efficient than plant roots In exchange, plants provide the fungus organic nutrients Mutualistic relationship because plant provides fungi with protection

Answer 60

diploid or haploid

Answer 61

Theres no genders in fungi just + or – strain

Answer 62

``` Sexual reproduction: Plasmogamy (fusion of cytoplasm) (Heterokaryotic stage) Karyogamy (zygote) (diploid) Meiosis(meiospores) (haploid) Germination (haploid) mycelium (haploid) ``` Asexual: all haploid spore producing structures make mitospores germination mycelium

Answer 63

The sexual processes of karyogamy and meiosis generate extensive genetic variation, a prerequisite for natural selection The heterokaryotic condition also offers some of the advantages of diploidy in that one haploid genome may compensate for harmful mutations in the other.

Answer 64

Many fungi reproduce asexually by growing as filamentous fungi that produce (haploid) spores by mitosis; such species are informally called moulds if they form visible mycelia by growing as single-celled yeasts. Instead of producing spores, asexual reproduction in yeasts occurs by ordinary cell division or by the pinching of small “bud cells” off a parent cell

Answer 65

Multicellular plant structure in which gametes are formed. Female gametangia are called archegonia, and male gametangia are called antheridia

Answer 66

1. Mycelia one (+)and one (-) 2. neighbouring mycelia of different mating types form hyphael extensions (gametangia) and the gametangia encloses several haploid nuclei (some from both mating types) 3. Plasmogamy: A zygosporangium forms containing multiple haploid nuclei from both parents HETEROKARYOTIC 4. the zygosporangium develops a rough thick cell walled coating that can resist harsh conditions for months 5. Karyogamy: (diploid nuclei) when conditions are favourable karyogamy occurs in meiosis 6. The zygosporangium germinates into a sporangium on a short stalk (HAPLOID) 7. The sporangium disperse genetically diverse haploid spores 8. the spores germinate and grow into new mycelia (HAPLOID) 9. Mycelia can also reproduce asexually forming sporangia that produce genetically identical haploid spores

Answer 67

life cycle follows the standard fungal cycle dominant stage: HAPLOID Asexual Stage: • Conidiospores are produced in structures called conidiophores (compare with the sporangia in Zygomycetes) Sexual Stage: 1. conidia of opposite mating type fuse to hyphae 2. Plasmogamy: dikaryotic hyphae produce many dikaryotic asci 3. Karyogmay:diploid- occurs within each ascus producing a diploid nucleus 4. Meiosis:(HAPLoid) each diploid nucleus divides by meiosis yielding 4 haploid nuclei 5. each haploid nucleus divides y mitosis making 8 nuclei , cell wall and plasma membrane develop around the nuclei forming ascocarp 6. Ascospores are discharged from asci germinating ones give rise to new mycelia * Ascospores (sexual spore) are produced in dikaryotic asci contained within ascocarps * Contain 8 ascospores per ascus * Conidia may be involved in sexual reproduction of a – conidiospore meets up with a + conidiospore

Answer 68

life cycle follows the standard fungal cycle Asexual Stage: none or very rare • Sexual Stage: 1. 2 haploid mycelia of different mating types undergo plasmogamy 2. A dikaryotic mycelium forms growing faster than and ultimately crowding out the haploid parental mycelia 3. Environmental cues cause the dikaryotic mycelium to form basidiocarps 4. the basidiocarp gills are lined with terminal dikaryotic cells called basidia 5. Karyogamy in each basidium produces a diploid nucleus which undergo meiosis 6. Each diploid nucleus yields 4 haploid nuclei each of which develop into basidospore 7. When mature the basidiospores are ejected and dispersed 8. In suitable environment the basidiospores germinate and grow into short lived haploid mycelia Basidiospores (sexual spore) are produced in dikaryotic basidia contained within basidiocarps • Contain 4 basidiospores per basidium

Answer 69

decomposers Break down wood, leaf litter, organic matter is soil Really any carbon-containing substrate->even jet fuel! Provides inorganic nutrients essential for plant growth

Answer 70

Endophytic fungi associate with plants Not limited to roots (compared to mycorrhizae), found in all plant tissues (leaves stems) Most are ascomycetes Provide a range of beneficial effects including producing anti-herbivory toxins, increasing heat/drought/heavy metal tolerance Animal mutualists Some occur in the guts of animals (chytrids in sheep) Ant colonies farming fungi for nutrients (Leaf cutter ants)

Answer 71

Symbiotic relationships between an ascomycete (or sometimes a basidiomycete or glomeromycete) fungus and a green alga and/or cyanobacterium Grow on various substrata: rocks, soil, trees, metal, concrete, plant leaves Most are terrestrial but some are aquatic ~13,000 species of lichens identified to date growth forms: fruticose(shrubs), foliose(leaf like broad lobes), crustose (super small foliose)

Answer 72

Sexual via fungal life cycle (ascomycete fungus it'll produce asci and ascospores germinate release into environment Asexual via soredia, fragmentation, other specialized structures (fungus plus algae in same blob and when they disperse if they find a favorable habitat they have both partners together and need to just grow on lichen)

Bacteria and Fungi Flashcards

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