Lecture 11 Flashcards
HD
What is the study of Fungi called?
Mycology
These are chemoheterotrophs, requiring organic compounds for energy and carbon. They are aerobic or facultatively anaerobic. Only a few anaerobic are known.
Fungi
These are nonfilamentous, unicellular fungi that are typically spherical or oval
Yeasts
Frequently found as a white powdery coating on fruits and leaves
Yeast
A general, imprecise term for any fungus which forms a visible layer of mycelium and/or spores on the surface of foods, walls, etc…but does not form macroscopic fruiting bodies
Mold
Multicellular fungi are identified on the basis of physical appearance, including what 2 things?
Colony characteristics and reproductive spores
An entire microscopic fungus is called
Thallus
The thallus (body) of a mold or fleshy fungus consists of long filaments of cells joined together; these filaments are called ____________
hyphae, (singular hypha).
The plant body is called
Thallo
In most molds, the hyphae contain cross-walls called __________, which divide them into distinct, uninucleate (one nucleus) cell-like units. These hyphae are called ________ _______
septa (singular septum), septate hyphae
In a few classes of fungi, the hyphae contain no septa and appear as long, continuous cells with many nuclei. These are called _________ _________
coenocytic hyphae
Hyphae grow and elongate at what point?
the tips
In the laboratory, fungi are usually grown from fragments obtained from a ______ _______. The portion of a hypha that obtains nutrients is called the ______ ______.
fungal thallus,vegetative hypha
The portion of hypha concerned with reproduction is the reproductive or ______ _______. So named because it projects above the surface medium on which the fungus is growing.
aerial hypha
When environmental conditions are suitable, the hyphae grow to form a filamentous mass called a ________, which is visible to the unaided eye.
mycelium
Filamentous fungi can reproduce _________ by fragmentation of their _______.
asexually, hyphae
Both sexual and asexual reproduction in fungi occurs by the formation of ________
spores
fungi are usually identified by ________
spore type
Are fungal spores asexual or sexual or both?
Both
Are asexual or sexual fungal spores formed by the hyphae of one organism?
Asexual - When these spores germinate, they become organisms that are genetically identical to the parent.
Do asexual or sexual fungal spores result from the fusion of nuclei from two opposite mating strains of the same species of fungus.
sexual
What occurs more frequently asexual or sexual?
Asexual
Organisms that grow from ______ spores will have genetic characteristics of both parental strains
sexual
Asexual spores are produced by an individual through _______ and subsequent cell division; there is no fusion of the nuclei of cells
mitosis
A form of nuclear division characterized by exact chromosome duplication
mitosis
One type of asexual spore is __________, a unicellular or multicellular spore that is not enclosed in a sac.
conidiospore
Conidiospores are produced in a chain at the end of a ________. Such spores are produced by __________.
conidiophore, Aspergillus.
Another type of conidiospore, ___________, consists of buds coming off the parent cell. Such spores are found in some yeast, such as Candida albicans and Cryptococcus
blastoconidia
Another type of asexual spore is __________, is formed by the fragmentation of a septate hypha into single, slightly thickened cells.
arthrospore
Another type of asexual spore is a ______________, a thick-walled spore formed by rounding and enlargement within the hyphal segment.
chlamydospore
Another type of asexual spore is a __________, formed within a sporangium, or sac, at the end of an aerial hypha called a sporangiophore. The sporangium can contain hundreds of sporangiospores.
sporangiospore
A fungal sexual spore results from sexual reproduction, consisting of three phases which are
Plasmogamy, Karyogamy. Meiosis
nucleus in which chromosomes are presented singly and unpaired
Haploid
A haploid nucleus of a donor cell(+) penetrates into the cytoplasm of a recipient cell(-) - is what phase of fungal spore reproduction
plasmogamy
The donor (+) and recipient (-) nuclei fuse to form diploid zygote nucleus - is what phase of fungal spore reproduction
Karyogamy
The diploid nucleus gives rise to haploid nuclei - is what phase of fungal spore reproduction
Meiosis
nuclei in which the chromosomes occur as homologous pairs, so that twice the haploid number is present
Diploid
A process occurring at different points in the life cycles of different organisms in which the chromosome number is reduced by half; compensates for the chromosome-doubling effect of fertilization. The sexual spores produced by fungi are the criterion used to classify the fungi into several divisions. In laboratory settings, most fungi exhibit only asexual spores and identification is based on microscopic examination of asexual spores.
Meiosis
5 Classifications of fungi
Chytridiomycetes, Ascomycetes, Basidiomycetes, Zygomycetes, Glomeromycetes
The fungi classified in the phylum Chytridiomycota, called ________, are ubiquitous in lakes and soil Some of the approximately 1,000 _______ species are decomposers, while others are parasites of protists, other fungi, plants, or animals (e.g. one such ________ parasite has likely contributed to the global decline of amphibian populations). Still other _______ are important mutualists. For example, anaerobic ______that live in the digestive tracts of sheep, cattle, kangaroos and other herbivores help to break down plant matter, thereby contributing significantly to the animal’s growth. _______ have flagellated spores and are thought to include some of the earliest fungal groups to diverge from other fungi
Chytrids (for all blanks)
This fungi include molds with septate hyphae and some yeast. Their asexual spores are usually conidiospores produced in long chains from the conidiophore. These spores freely detach from the chain at the slightest disturbance and float in the air like dust.
Ascomycota, or sac fungi,
This phylum includes fungi that produce mushrooms.
Basidiomycota, or club fungi,
How many basidiospores are there usually per basidium
four
Can some basidiomycetes produce asexually?
Yes
Saprophytic molds that have coenocytic hyhae
Zygomycota, or conjuction fungi
This is a large spore enclosed in a thick wall. This kind of spore results from the fusion of the nuclei of two cells those are morphologically similar to each other
Zygospore
In pathogenic fungi is temperature-dependent. At 37°C, the fungus is yeastlike, and at 25°C, it is moldlike. Mucor rouxii exhibits yeastlike growth, but in the agar it is mold-like with changing CO2 concentrations
Diamorphism
Some fungi most notably the pathogenic species, exhibit ____________(two forms of growth). Such fungi can grow either as a mold or as yeast. The moldlike forms produce vegetative and aerial hyphae, the yeast like forms reproduce by budding.
dimorphism
The edible part of the mushroom.
Fruiting bodies
Fruiting bodies formed through the association of a large number of individual hyphae to form a __________.
mycelium
What are 3 ways that yeasts can reproduce? What is the most common?
Sporulation, budding, or fission.
Most common - budding
Budding yeasts, such as Saccharomyces divide ________.
unevenly.
In budding, the parent cell forms a ________ on its outer surface. As the bud elongates, the parent cell’s nucleus divides, and one nucleus migrates into the bud. Cell wall material is then laid down between the bud and parent cell, and the bud eventually breaks away
protuberance
Yeasts can use ________ or an ________ ______as the final electron acceptor and as a result they can survive in various environments.
oxygen, organic compound
Yeasts are capable of what type of growth.
facultative anaerobic
If given access to oxygen, yeasts perform aerobic respiration to metabolize carbohydrates to _______ and _________
carbon dioxide and water.
If yeasts are denied oxygen, they ferment carbohydrates, and produce ________ and _________. This fermentation is used in the brewing, wine making, and baking industries.
ethanol and carbon dioxide
This organism is a combination of a green alga (or a cyanobacterium) and a fungus
Lichen
Lichens are placed in the Domain Fungi and are classified according to the fungal partner, most often an ___________.
ascomycete
Lichen is an example of what kind of relationship?
Mutualistic relationship (each partner benefits)
Approximately 13,500 species of lichens occupy quite diverse habitats. Because they can inhabit areas in which neither fungi nor algae could survive alone, lichens are often the first life forms to colonize _________ or _________
newly exposed soil or rock.
Also found on trees, concrete structures, and rooftops, ________ are some of the slowest-growing organisms on Earth.
lichens
Lichens secrete ______ _____ that chemically weather rock, and they accumulate nutrients needed for plant growth.
organic acids
Lichens can be grouped into three morphological categories which are:
Crustose lichens
Foliose lichens
Fruticose lichens
What type of lichens grow flush or encrusting onto the substratum.
Crustose
What type of lichen are lichens are more leaf-like?
Foliose
What type of lichens have fingerlike projections?
Fruticose
The lichen’s thallus, or body, forms when fungal hyphae grow around algal cells to become the ___________.
medulla.
Fungal hyphae also form a ______, or protective covering, over the algal layer and sometimes under it as well. The fungus clearly benefits from this association.
cortex
Populations of lichens readily incorporate ________ into their thalli. Therefore, the concentrations and types of _________ in the atmosphere can be determined by chemical analysis of lichen thalli. In addition, the presence or absence of species that are quite sensitive to pollutants can be used to ascertain air quality.
cations, cations
They are mostly aquatic, although some are found in soil or on trees when sufficient moisture is available there. _______ are familiar as the large brown kelp in coastal waters, the green scum in a puddle, and the green stains on soil or on rocks.
Algae
In algae, _______ is necessary for physical support, reproduction, and the diffusion of nutrients.
water
The body of a multicellular alga is called _______.
thallus.
Thalli of the larger multicellular algae, those commonly called _________, consist of branched holdfasts (which anchor the alga to a rock), stem like and often hollow stripes, and leaf like blades
seaweeds
The cells covering the thallus of algae can carry out __________.
photosynthesis.
What part of the algae absorb nutrients from the water?
entire surface
some algae are also buoyed by a floating, gas filled bladder called a __________
pneumatocyst.
Do algae reproduce sexually, asexually or both
both
When a unicellular alga divides, its nucleus divides (mitosis), and the two nuclei move to opposite parts of the cell. The cell then divides into two complete cells which is called.
cytokinesis
In some species, asexual reproduction may occur for several generations and then, under different conditions, the same species reproduce sexually. Other species alternate generations so that the offspring resulting from sexual reproduction reproduce asexually, and the next generation then reproduces sexually.
FYI
Algae are __________and are therefore found throughout the photic (light zone) of bodies of water
photoautotrophs
___________ a (a light-trapping pigment) and accessory pigments involved in photosynthesis are responsible for the distinctive colors of many algae.
Chlorophyll
______ a thickener used in many foods (such as ice cream or cake decorations), is extracted from the cell walls of brown algae. _______is also used in the production of a wide variety of nonfood goods, including rubber tires and hand lotion.
Algin, Algin
Unicellular or filamentous algae with complex cell walls that consist of pectin and a layer of silica. Two two parts of the wall fit together like the halves of a Petri dish.
Diatoms
Diatoms can be identified by
distinctive patterns in their walls
Diatoms store energy captured through photosynthesis in the form of _____.
oil
These are unicellular algae collectively called plankton, or free-floating organisms. Their rigid structure is due to cellulose embedded in the plasma membrane. Some of them produce neurotoxins. In the last 20
years, a worldwide increase in toxic marine algae has killed millions of fish, hundreds of marine mammals, and even some humans.
Dinoglagellates
When fish swim through large numbers of the dinoflagellate Gymnodinium breve, the algae trapped in the gills of the fish release a neurotoxin that stops the fish from breathing. Dinoflagellates in the genus ___________ produce neurotoxins (called saxitoxins) that cause___________________.
The toxin is concentrated when large numbers of dinoflagellates are eaten by mollusks, such as mussels or clams. Humans who eat these mollusks develop PSP. Large concentrations of Alexandrium give the ocean a deep _____ color, from which the name _____ ______ originates. Mollusks should not be harvested for consumption during this. A disease called ______ occurs when the dinoflagellate Gambierdiscus toxicus passes up the food chain and is concentrated in large fish.
Alexandrium, paralytic shellfish poisoning (PSP), red, red tide, ciguatera
Algae are an important part of any aquatic food chain because they fix ______ _______ into molecules that can be consumed by chemoheterotrophs.
carbon dioxide
Using the energy produced in photophosphorylation, algae convert carbon dioxide in the atmosphere into ___________. ______ ________ is a by-product of their photosynthesis
carbohydrates. Molecular oxygen
The top few meters of any body-water contain _______ algae
planktonic
As 75% of the Earth is covered with water, it is estimated that 80% of the Earth’s oxygen is produced by ________ algae.
planktonic
periodic increases in numbers of planktonic algae are called ______ ______.
algal blooms.
These are unicellular, eukaryotic chemoheterotrophic organisms, which inhabit in water and soil. Some are part of the normal microbiota of animals.
protozoa
Of the nearly 20,000 species of protozoa, _______ cause disease.
relatively few
How do protozoa reproduce?
asexually by fission, budding, or multiple fission. Sexually has also been observed
Protozoa reproduce asexually by fission, budding, or multiple fission, which is called __________
schizogony
the nucleus undergoes multiple divisions before the cell divides. After many nuclei are formed, a small portion of cytoplasm concentrates around each nucleus, and then the single cell separates into daughter cells.
schizogony
unicellular, eukaryotic chemoheterotrophic organisms, which inhabit in water and soil
Protozoa
Of the nearly 20,000 species of protozoa, relatively few cause disease or most cause disease?
few
The ciliates such as Paramecium, reproduce sexually by _________ which is different than the bacterial one.
conjugation
two cells fuse, and a haploid nucleus (micronucleus) from each cell migrates to the other cell.
protozoan conjugation
Under certain adverse conditions, some protozoa produce a protective capsule called a _______.
cyst.
A cyst permits the organism to survive when food, moisture, or oxygen is lacking, when temperatures are not suitable, or when toxic chemicals are present. A cyst also enables a parasitic species to survive outside a host.
FYI
Are protozoa mostly chemotrophs, autotrophs, or heterotrophs? Aerobic or anaerobic
Aerobic heterotrophs, although many intestinal protozoa are capable of anaerobic growth
All protozoa live in areas with large supply of _______.
water
Some protozoa transport food across the _____ ______.
plasma membrane
Some protozoa have protective covering, or ______, and thus require specialized structures to take in food.
pellicle
Ciliates take food by waving their cilia toward a mouthlike opening called a ________
cytostome.
_________ engulf food by surrounding it with pseudopods and phagocytizing it.
Amoebas
In all protozoa, digestion takes place in membrane-enclosed ________, and waste may be eliminated through the plasma membrane or a specialized anal pore.
vacuoles
Slime Molds have both fungal and amoebal characteristics and are probably more closely related to _________.
amoeba.
What are the two phyla of slime molds
cellular and plasmidial
What phyla of slime mold are typical eukaryotic cells that resemble amoebas
cellular
What phyla of slime mold exist as a mass of protoplasm with many nuclei? This mass of protoplasm is called a _______.
plasmodial, plasmodium.
These are parasitic animals that spend part of their lives in humans
Helminths
What are 2 phyla of helmithes?
Platyhelminthes (flatworms) Nematoda (roundworms)
These are animals characterized by segmented bodies, hard external skeletons, and jointed legs.
arthropods
Although not microbes themselves, they can transmit microbial diseases through blood suction. Arthropods that carry pathogenic microorganisms are called ________.
vectors.
What are 3 types of arthropods?
Arachnida (eight legs): spiders, mites, ticks Crustacea (four antennae): crabs, crayfish
Insecta (six legs): bees, flies, lice
