What features do archaebacteria represent?
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A combination of prokaryotic and eukaryotic features.
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What features do archaebacteria represent?
A combination of prokaryotic and eukaryotic features.
What can adversely affect the growth of bacteria?
Organic compounds.
What do iron bacteria oxidize and what is produced in this process?
They oxidize ferrous compounds into ferric forms, releasing energy used in the synthesis of organic compounds.
What are the two subgroups of autotrophs based on energy source?
Phototrophs and Chemotrophs.
What are the four distinct regions recognized in an advanced foliose lichen?
Upper cortex, lower cortex, medulla, and algal layer.
What are four well-known examples of green sulfur bacteria?
Chlorobium, Prosthecochloris, Pelodictyon, and Clathrochloris.
What is a common name for vibrios?
'Comma bacteria'.
What shape do vibrios have?
Slightly curved rods resembling a comma.
What is the internal structure of lichens composed of?
A combination of algal and fungal components.
Do archaebacteria have membrane-bound cell organelles?
No, they lack membrane-bound cell organelles.
What is the term used for the thallus composed of algal and fungal components?
Consortium.
What role do lichens play in new terrains?
They are pioneer organisms that colonize bare rocks, cliffs, and mountains.
Where are chlorophyll pigments located in bacteria?
Within involuted cytoplasmic membranes.
What are the three representative groups of Archaebacteria?
Methanogens, Halophiles, Thermoacidophilic bacteria.
What is a unique feature of the cell wall of archaebacteria?
It does not contain peptidoglycan.
What are Archaebacteria often referred to as?
Living fossils.
Where do Methanogens typically inhabit?
Sewage swamps and the digestive tract of animals.
What are iron bacteria and where do they form colonies?
Iron bacteria, such as Sphaerotilus and Ferrobacillus, form natural colonies in fresh water ponds and springs with high contents of reduced sulphur salts.
What is the size range of cocci bacteria?
0.5 - 2.25 μm in diameter.
What is the fungal component of lichens called?
Mycobiont.
In which kingdom are bacteria placed?
Procaryotae.
What is the growth rate of lichens dependent on?
Both the species and the environmental conditions around them.
What pigments do purple sulfur bacteria use for photosynthesis?
Bacteriochlorophyll a and/or b.
Can a single bacterium exhibit more than one shape during its life cycle?
Yes, a single bacterium may occur in more than one shape in its life cycle.
What provides the reducing power for purple sulfur bacteria?
H2S, which is oxidized anaerobically to sulfate.
How can chemoautotrophs be classified?
Based on substrate specificity.
What other compounds can some purple sulfur bacteria use instead of H2S?
Thiosulfate, sulfite, etc.
How do lichens contribute to soil formation?
They erode rocks and accumulate minerals and organic matter.
What are rod-like bacteria called?
Bacilli.
Are there intercellular spaces between the hyphae in the upper cortex?
Usually no; if present, they are filled with gelatinous substances.
What is a key prokaryotic feature of archaebacteria?
Absence of organized nucleus with nuclear envelope, nucleolus, and organized chromosomes.
What are spherical bacteria called?
Cocci (singular: coccus).
What is the algal component of lichens called?
Phycobiont.
What ability do photosynthetic bacteria share with higher plants?
They can convert radiant energy into chemical energy.
What happens to the ferric iron produced by iron bacteria?
It is deposited as insoluble ferric hydroxide.
What is the width range of vibrios?
1.5 - 1.7 μm.
What is the function of the upper cortex in lichens?
It serves as the outermost thick and protective zone of the thallus.
What are micrococci?
Cocci that occur singly, such as Micrococcus cerolyticus, M. cyrophilus, and M. luteus.
What are pili in gram-negative bacteria?
Minute hair-like cytoplasmic appendages extruding through the cell wall.
What are the fungal components of lichens primarily classified as?
Basidiomycetes or Ascomycetes.
What protein composes the pili in gram-negative bacteria?
Fimbrillin.
What is the average diameter of bacillus bacteria?
About 0.5 μm.
How do bacteria reproduce?
Primarily through binary fission.
What is the chemical equation representing the process involving green sulfur bacteria?
6 CO2 + 12 H2S → 12 (CH2O) + H2SO4.
What does pleomorphic mean in the context of bacteria?
It refers to bacteria that can change their shape and size temporarily in response to environmental changes.
What is the most common mode of nutrition for bacteria?
Heterotrophic mode of nutrition.
What is the generalized reaction of photosynthesis in photosynthetic bacteria?
CO2 + 2 H2A → (CH2O) + H2O + 2A.
Where do sulphur bacteria occur?
In sulphur-containing terrestrial and aquatic environments.
What is the arrangement of hyphae in the upper cortex of lichens?
They are arranged at right angles to the surface of the thallus.
What is the algal layer in lichens?
The algal layer occurs just below the upper cortex and is also known as the gonidial layer.
What genetic feature is present in archaebacteria but absent in prokaryotes?
Introns in the gene sequence.
Where can Archaebacteria typically be found?
In extreme environments such as hot springs, salt lakes, and deep-sea vents.
Which organisms do lichens use to fix nitrogen?
Cyanobacteria.
What are photosynthetic bacteria also known as?
Photoautotrophic or photolithotrophic bacteria.
How long are vibrios typically?
About 10 μm.
Is true sexual reproduction present in bacteria?
No, true sexual reproduction is absent in bacteria.
What type of ribosomes do archaebacteria possess?
70 S ribosomes, which are typical of prokaryotes.
What are spherical bacteria called?
Cocci.
What is the arrangement of cocci bacteria?
They often occur in chains or clusters of variable size and shapes.
What type of bacteria possess bacteriochlorophyll?
Autotrophic bacteria.
Name two examples of vibrios.
Vibrio coli and V. cholerae.
What is the cellular structure of bacteria?
Unicellular and morphologically least complex.
How do sulphur bacteria derive energy?
By the oxidation of reduced sulphur compounds.
What are lichens?
A small group of curious plants that resemble moss and grow on surfaces like rocks, trees, and walls.
What two components make up lichens?
Algal and fungal components.
What are the four common forms of bacteria?
Spherical, rod-like, curved, and spiral.
What do Methanogens produce?
Methane.
What are spiral or helical bacteria also known as?
Spirilla (singular: spirillum).
What is the process of fixing nitrogen?
Changing unusable nitrogen into a usable form.
What are some common green and blue-green algae found in lichens?
Species of Protococcus, Pleurococcus, Cladophora, Trebauxia, Trentepohilia (Chlorophyceae), and Nostoc, Glococapsa, Rivularia (Myxophyceae).
What types of plants appear later in succession after lichens?
Grasses and mosses.
How do bacterial ribosomes compare to those of other organisms?
They sediment somewhat more slowly in a centrifuge.
Where do Archaebacteria typically inhabit?
Anaerobic environments, such as extremely saline, acidic, or hot environments.
What is the medulla in lichens?
The central part of the thallus, comprised of loosely interwoven fungal hyphae with large spaces between them.
What are viruses classified as?
Simple and acellular infectious agents.
How does the internal structure of crustose lichens compare to foliose lichens?
It is more or less similar.
What pigments do purple sulfur bacteria use for photosynthesis?
Bacteriochlorophyll a and/or b.
Name an example of bacillus bacteria.
Bacillus anthracis.
What are the nutritional requirements of methanogenic archaebacteria?
They have simple nutritional requirements and can be either autotrophs or forms that use a variety of carbon compounds.
What does the alga in lichens synthesize for both components?
Organic food materials.
What is the function of bacteriorhodopsin in archaebacteria?
It utilizes light energy for the production of ATP.
What do lichens secrete to help dissolve rocks?
Organic acids such as carbonic acids.
What was the basis for the classification of bacteria in the first edition of the Manual published in 1923?
Phenotypic characterization.
What are curved bacteria called?
Vibrios.
How do lichens contribute to soil formation?
By adding organic matter when they die.
What is the branch of science that studies viruses called?
Virology.
Why are lichens considered pollution indicators?
They are present in areas with low pollution levels.
What shape are the male sex organs of lichens?
Flask-shaped.
In what conditions do chemoautotrophs grow?
In a strictly mineral medium and in the dark.
How can scientists use lichens to assess air quality?
By extracting toxins from lichens to determine levels of air pollution.
Where do methanogenic bacteria occur and what do they produce?
They occur in waste disposal plants and produce methane (biogas).
What occurs if there is greater oxidation of the substrate in non-sulfur purple bacteria?
CO₂ is given off, similar to respiration.
In which kingdom are bacteria classified in the five kingdom classification system?
Kingdom Monera.
What diseases can pathogenic bacteria cause in plants and animals?
Citrus canker in plants and pneumonia, typhoid in animals.
What is the role of root nodule bacteria (Rhizobium)?
They fix atmospheric nitrogen to augment the nitrogen supply for leguminous plants.
What is the fruiting body structure of Pyrenocarpeae?
A flask-shaped perithecium.
What conditions can lichens survive?
High temperature and dry conditions.
What type of environment is believed to have existed before the emergence of life on Earth?
A highly anaerobic and warm environment.
What are autotrophic bacteria?
Bacteria capable of synthesizing their food by themselves from organic and inorganic substances.
Where can bacteria be found?
In all possible habitats.
Give an example of a pleomorphic bacterium.
Acetobacter, which can be seen as bacillus or streptobacillus.
What do motile bacteria possess for movement?
One or more flagella composed of eight parallel chains of flagellin.
What organelles are absent in bacteria?
Mitochondria, endoplasmic reticulum, and Golgi apparatus.
How does the plant body of lichens compare to algae and fungi?
It neither resembles algae nor fungi.
What are bacteria?
Single-celled microorganisms that can exist independently or as parasites.
What does the sulphur bacterium Beggiatoa oxidize?
Hydrogen sulphide to elemental sulphur.
What significant role did Archaebacteria play in the evolution of life on Earth?
They transformed the initial environment by accumulating organic substances before the evolution of photosynthesis.
What does the algal component of lichens produce through photosynthesis?
Carbohydrates, which are utilized by both the algal and fungal components.
How do spirilla typically occur?
Singly or in small chains.
What determines the extent of CO₂ reduction in non-sulfur purple bacteria?
The organic substrate used.
Where do viruses replicate and show living properties?
Inside the living cells of other organisms.
What is the most common form of bacteria?
Bacillus or rod-shaped bacteria.
How are algal cells and fungal filaments arranged in species like Parmelia and Physcia?
They are interwoven within the thallus.
What characterizes crustose lichens?
They have an inconspicuous, thin, and flat thallus that is firm in texture.
What is the decomposition of carbohydrates by saprophytic bacteria known as?
Fermentation.
What are the two types of fruiting bodies in lichens?
Apothecia (disc-shaped) and perithecia (flask-shaped).
What variations can exist in the shape of bacilli?
They may have rounded or blunt ends, and can vary from very short to long and narrow.
What are halophilic archaebacteria?
They are salt-loving aerobes that thrive in salt lakes, tidal pools, and salt brines.
How is alcohol produced from lichens in Sweden and Russia?
From species like Cetraria islandica, which contain carbohydrates in the form of lichenin.
Which bacteria carry out lactic acid fermentation of milk?
Lactic acid bacteria (Lactobacillus).
What occurs during putrefaction?
Reduction of protein to peptone, polypeptide, peptides, and amino acids.
What do many saprophytic bacteria require for breaking down amino acids?
Oxygen.
What type of nucleus do bacteria lack?
A well-organized nucleus characteristic of eukaryotes.
Is the nuclear material in bacteria surrounded by a nuclear membrane?
No, it is not surrounded by a nuclear membrane.
Are cocci bacteria motile or non-motile?
Non-motile.
What are hydrogen bacteria capable of utilizing?
Molecular hydrogen.
What are the three types of heterotrophic bacteria?
Parasitic, saprophytic, or symbiotic.
What is a characteristic feature of vibrios?
A single flagellum at its tip.
In higher plants, what substitutes for A in the photosynthesis reaction?
Oxygen.
What are some common examples of purple sulfur bacteria?
Chromatium, Thiocystis, Thiospirillum, and Amoebobacter.
What structure in bacteria carries out the function of mitochondria?
Complex localized infoldings in the cell membrane known as mesosomes.
What conditions do Archaebacteria retain adaptations for?
Very high levels of temperature, pH, and salt concentration.
What is a key characteristic of non-sulfur purple bacteria?
They are motile and do not produce gas vacuoles or accumulate sulfur.
How are bacteria distinguished from other microorganisms?
Based on their typical prokaryotic structure.
What is the average length of bacillus bacteria?
About 1.5 μm.
What are common H2-oxidizing bacteria?
Pseudomonas saccharophila and P. facilis.
Which type of bacteria are most abundant and important geochemical agents?
Chemosynthetic bacteria.
What photosynthetic pigment do non-sulfur purple bacteria possess?
Bacteriochlorophyll.
What is Bergey's Manual of Determinative Bacteriology?
The standard reference book for classification and identification of bacteria.
Which lichens are known for producing delicate perfume?
Lobularia pulmonaria and Evernia prunastri.
What biological stain is obtained from Rocella tinctoria?
Orcein.
What are the male sex organs of lichens called?
Spermogonia.
Why are Archaebacteria considered a primitive group of organisms?
Because they still retain adaptations for living under primitive Earth conditions.
What types of pollutants can lichens absorb?
Heavy metals, carbon, sulfur, and other pollutants.
What are endosymbionts?
Symbiotic bacteria that live inside the host tissue.
What types of pollutants can some lichens tolerate?
Sulphur and nitrogen compounds.
What role does lichen ground cover play in tundra ecosystems?
It helps to insulate the ground and may provide forage for grazing animals.
What are Ascolichens?
Lichens where the fungal component is a member of the class Ascomycetes.
How does the fungal component protect the alga in lichens?
From high temperature and desiccation.
What is the fruiting body structure of Gymnocarpeae?
A disc-like apothecium.
What is the decomposition of proteins by saprophytic bacteria known as?
Putrefaction.
What type of organisms are bacteria believed to be among the first on Earth?
Primitive organisms.
What is an example of halophilic archaebacteria?
Halobacterium.
Where have extremely thermophilic microorganisms been recently discovered?
Mainly from volcanic walls.
What is the size and differentiation level of bacteria?
They are microscopic and the least differentiated living organisms.
What is the basis for dividing autotrophs into lithotrophs and organotrophs?
The nature of substances oxidized; lithotrophs utilize inorganic substances, while organotrophs oxidize organic matter.
What methods do bacteria use for genetic recombination?
Conjugation, transformation, and transduction.
How do lichens convert nitrogen in the air?
By associating with algae to convert it into nitrates.
What are the algal components of lichens primarily classified as?
Chlorophyceae or Myxophyceae.
What happens to nitrates when it rains?
They are leached from lichens.
What is the end product of the photosynthesis process in higher plants?
Free oxygen.
What are the two main groups of bacteria based on their mode of nutrition?
What type of structure do lichens have?
A composite thalloid structure formed by the association of algae and fungi.
What are diplococci?
Cocci that occur in pairs, exemplified by Diplococcus pneumoniae.
What is the size range of bacteria?
Typically between 0.5 to 5 micrometers in diameter.
What is the role of Nitrobacter in bacteria?
Nitrobacter carries out oxidation, using nitrite as its only source of energy.
How do lichens affect the erosive potential of downpours?
They absorb much of the raindrops' force, greatly lessening erosive potential.
How do lichens transform barren regions?
By converting them into areas that can support vegetation.
What is a key feature of Archaebacterial cell membranes?
They contain unique lipids that differ from those found in bacteria and eukaryotes.
What do nitrifying bacteria oxidize?
Ammonia to nitrate.
What are the three major nutritional categories of heterotrophic bacteria?
Parasitic bacteria, saprophytic bacteria, and mutualistic bacteria.
How do some hyphae in the lower cortex become specialized?
They extend downward from the lower surface of the cortex to help in attachment.
What is the significance of nitrifying bacteria in nature?
They help greatly in the economy of nitrogen.
What are parasitic bacteria?
Bacteria that feed on living organisms.
What do spermogonia produce?
Spermatia.
What characteristics do bacilli have?
They are rod-shaped, cylindrical or elongate, and can be motile or non-motile.
Where can thermoacidophilic archaebacteria typically be found?
In hot sulphur springs.
Which lichen is known as Iceland moss and is consumed in Scandinavian countries?
Cetraria islandica.
How many ascospores does an ascus produce?
Eight.
What are lichen acids useful for?
Identification and classification of lichens.
How was Evernia prunastri used by the Egyptians?
As baking powder.
How do bacteria resemble other living organisms?
They have resemblance with both plants and animals.
What specific acid do lichens produce?
Lichen acid.
Where is sulfur deposited in purple sulfur bacteria?
Intracellularly (extracellularly in Ectothiorhodospira).
What is scented incense obtained from?
Species of Ramalina and Evernia.
What do hydrogen bacteria produce when they oxidize molecular hydrogen?
Water and energy.
What distinguishes non-sulphur purple bacteria from purple sulphur bacteria?
Non-sulphur purple bacteria can grow in the presence of oxygen.
What is the composition of the bacterial cell wall?
Made up of amino acid subunits and saccharide subunits.
What percentage of lichens have algal components from Chlorophyceae?
About 75%.
What makes archaebacteria unusual monerans?
They possess certain peculiar characters.
What is the typical length of a spirillum?
Up to 15 μm.
What conditions are required for methanogenesis to occur?
An oxygen-free environment at temperatures from about 10 °C to 100 °C.
What happens to elemental sulphur in Beggiatoa?
It is deposited in the filaments as minute granules.
What do saprophytic bacteria grow on?
Dead and decaying organic matter.
What term is used for lichens where algal cells and fungal hyphae are uniformly distributed?
Homoisomerous.
What is the role of bacteria in the ecosystem?
They decompose organic matter and recycle nutrients.
What are sarcinae?
Spherical bacteria that divide in three planes, forming a cuboidal arrangement, such as Sarcinae lutea and S. verticuli.
In what industries are some species of lichens useful?
Brewing, distilling, tanning, and dyeing.
What nutrients are lichens rich in?
Polysaccharides, some vitamins, and certain enzymes.
What types of organisms benefit from lichens as a habitat?
Insects, arthropods, and other small invertebrates.
What is the first step of nitrification?
Oxidation of ammonia or ammonium ions to nitrate by Nitrosomonas.
What is the lung wart lichen used for?
Tanning, brewing, and as a substitute for hops in brewing.
What is a common example of fermentation?
Breakdown of sugars by yeast, releasing CO2.
What occurs in the second step of nitrification?
Oxidation of nitrite to nitrate.
What are Pyrenocarpeae also known as?
Pyrenolichens (e.g., Dermatocarpon).
How are bacteria classified based on nutrition?
Bacteria are classified into two groups: Autotrophic bacteria and Heterotrophic bacteria.
How do the ribosomal RNA and protein synthesis mechanisms of archaebacteria compare to eukaryotes?
They are similar to their eukaryotic counterparts.
What is a key characteristic of bacterial photosynthesis?
Oxygen is never released during photosynthesis.
What term is used for bacteria that are intermediate between cocci and bacilli?
Coccobacilli.
What is the common name for a lichen used as a fixative in perfumes in Southern Europe?
Oak moss.
What is the chemical equation representing the process involving green sulfur bacteria?
6 CO2 + 12 H2S → 12 (CH2O) + H2SO4.
What is one medicinal use of lichens?
Preparation of ointment for wounds and burns.
Is cellulose present in the cell wall of bacteria?
No, cellulose is absent in bacteria.
In lichens, what is the nature of the relationship between algal and fungal components?
Symbiotic, where both are equally benefited.
What is the function of the lower cortex in lichens?
It is composed of compactly arranged hyphae that help in the attachment of the thallus to the substratum.
What are ectosymbionts?
Symbiotic bacteria that live on the surface of the host.
What is the shape and motility of green sulphur bacteria?
They are small, nonmotile, rod-shaped bacteria.
How are bacillus bacteria classified?
Based on their arrangement.
What are Deuterolichens?
Lichens where the fungal component is a member of the class Deuteromycetes.
What is the photosynthetic pigment found in green sulphur bacteria?
Chlorobium chlorophyll.
What are bacillus bacteria called when they occur in pairs?
Diplobacillus.
How are lichens classified based on the structure of their thallus?
Into three broad types: crustose, foliose, and fruticose.
What alternative compounds can some purple sulfur bacteria use instead of H2S?
Other reduced sulfur compounds like thiosulfate and sulfite.
How do symbiotic bacteria assist in digestion?
They secrete enzymes that help in the digestion of cellulose.
From which lichen is litmus obtained?
Rocella mountaignel.
What is the sole source of energy for Nitrosomonas?
The oxidation of ammonia.
What do leguminous plants provide to root nodule bacteria?
Shelter and carbohydrates.
What are the two parts of the carpogonium in lichens?
A basal coiled ascogonium and an elongated multicellular trichogyne.
With what type of bacteria are halophilic archaebacteria frequently associated?
Coccoid bacteria.
How are cocci classified?
Based on the arrangement and the number of cells in a cluster.
Which lichens are reported to have perfumed volatile oils used in cosmetics?
Evernia, Ramalina, and Pseudorina.
What are four well-known examples of green sulfur bacteria?
Chlorobium, Prosthecochloris, Pelodictyon, and Clathrochloris.
What type of bacteria are anaerobic and do not release oxygen during photosynthesis?
Anaerobic photoautotrophic bacteria.
How do lichens absorb water and nutrients?
Through their surface.
What are fungus-like bacteria?
Bacteria that form branched filaments, such as Actinomyces and Streptomyces.
In non-sulfur purple bacteria, what can replace sulfur in their metabolism?
Some organic compounds.
What pigment do archaebacteria possess in their purple membranes?
Bacteriorhodopsin.
What are the common colors of lichens?
Usually grey or greyish green, but can also be yellow, red, orange, or brown.
How do Archaebacteria obtain energy?
Through various metabolic pathways, including methanogenesis, sulfur reduction, and photosynthesis.
What is the basis for further treatment of the kingdom Procaryotae?
Cellular characteristics.
What is the role of the fungal component in lichens?
Responsible for the absorption and retention of water.
What is the significance of Archaebacteria in evolutionary biology?
They provide insights into the early evolution of life on Earth and the origins of eukaryotes.
What are the two major groups of bacteria based on morphology?
Unicellular and Mycelial.
Name a common example of a spirillum.
Spirillum undulum, S. volutans, or S. minus.
What is litmus used for in laboratories?
As an acid-base indicator.
How does the thallus of crustose lichens interact with the substratum?
It is very closely adhered to the substratum and provides a crust-like appearance.
How do birds utilize lichens?
They use different species of lichens, usually fruticose types, to build their nests.
What is the culinary use of species of Parmelia or rock flower?
Used in curry preparation.
What type of cellular characteristics do bacteria exhibit?
Typical prokaryotic characters.
What is notable about the growth rate of lichens?
It is extremely slow.
How do fruticose lichens grow?
They grow erect or hang from the substratum.
What are filamentous bacteria?
Bacteria that form unbranched filamentous structures, like Beggiatoa and Thiothrix.
What is the typical diameter of a spirillum?
About 1.5 μm.
What are streptococci?
Spherical bacteria that occur in long chains, such as Streptococcus lactis and S. pyogenes.
What type of bacteria are nitrifying bacteria?
Soil-borne obligate autotrophs.
How are algal cells arranged in some lichen species like Collema and Leptogium?
In these species, algal cells and fungal hyphae are distributed more or less uniformly throughout the thallus.
What do lichens absorb from the atmosphere that benefits humans?
Pollutants and potentially toxic compounds.
What are bacteria considered in terms of cellular organization?
The smallest and most successful prokaryotes.
What is absent in fructicose lichens due to their cylindrical structure?
The lower cortex.
What have the fungal components of some lichen species been used for?
As dyes in coloring fabrics and paints.
What is the economic importance of certain species of lichens?
They are valuable sources of food.
What is one of the dyes produced by lichens?
Orchill.
What are some nutritional classifications of bacteria?
Autotrophs, heterotrophs, and chemotrophs.
What is the organism called from which parasitic bacteria obtain their food?
Host.
Who discovered the tobacco mosaic virus and in what year?
Beijerinck in 1898.
What is a frequent limitation of chemosynthetic bacteria?
Inability to use organic compounds as energy and carbon sources.
What happens to the thallus of crustose lichens in relation to the substratum?
It is wholly or partially embedded in the substratum, with only fruiting bodies visible above the surface.
What is the female sex organ in lichens called?
Carpogonium.
What species of lichen is prized as food in Southern India?
A species of Parmelia.
What is Lecanora esculenta commonly known as?
Manna lichen.
What is Cetraria islandica used for?
As fodder for horses.
What substance secreted from Usnea barbata is effective in tuberculosis?
Usnic acid, along with Streptomycin.
What are gonidium cells?
Gonidium cells are reproductive cells of algae found in the algal layer of lichens.
What is the process of methane production in Methanogens called?
Methanogenesis.
What is the most common method of multiplication in bacteria?
Binary fission.
How do heterotrophic bacteria obtain their food?
They obtain their readymade food from any organic source.
Where are lichens most noticeable?
On the tundra.
What are the main shapes of bacteria?
Cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped).
From where do chemosynthetic bacteria derive their energy?
From ammonia, nitrate, nitrite, ferrous iron, hydrogen sulphide, and other inorganic compounds.
What do lichens, mosses, and liverworts constitute in tundra ecosystems?
The majority of ground cover.
Who first discovered and described bacteria?
Antony van Leeuwenhoek in 1676.
What type of structures do lichens have to anchor themselves?
Root-like structures (but not true roots).
What are thermoacidophilic archaebacteria?
Aerobes that inhabit hot and acidic environments.
How many steps are involved in the nitrification process?
Two steps.
What term is used for lichens where algal cells and fungal filaments are interwoven?
Heteromerous.
How do lichens reproduce asexually?
By forming various types of asexual spores, such as oidia and pycnidia.
What are bacillus bacteria called when they occur in long chains?
Streptobacillus.
Name some examples of foliose lichens.
Parmelia, Physcia, Peltigera, Xanthoria, Gyrophora, and Collema.
What do plant viruses infect?
Only plants.
What is the shape of halophilic archaebacteria?
They are rod-shaped forms.
Do anaerobic bacteria require oxygen for putrefaction?
No, the process does not require oxygen.
Which lichen species are commonly used as fodder for animals?
Stereocaulon, Evernia, Parmelia, and Lecanora.
What are symbiotic bacteria?
Bacteria that grow in close (beneficial) association with other living organisms.
What are tetracocci?
Cocci that form groups of four cells, like Pedicoccus cerevisiae and Neisseria.
What are the two divisions of Procaryotae?
Cyanobacteria and Bacteria.
What are Basidiolichens?
Lichens where the fungal component is a member of the class Basidiomycetes.
What role do lichens play in erosion control?
They enrich the soil by trapping water, dust, and silt.
What does Thiobacillus thiooxidans utilize?
Free sulphur.
How are lichens classified based on external morphology?
They are classified into three types based on thallus organization.
How do saprophytic bacteria obtain their food?
By decomposing complex organic molecules into simple inorganic constituents.
What does Thiobacillus thiooxidans produce?
Sulphuric acid.
How are foliose lichens attached to their substratum?
By rhizoid-like outgrowths called rhizines.
What significant role do lichens play in nitrogen fixation?
They can be a significant source of nitrogen for plants.
What is methane used for?
It is utilized in various domestic and industrial processes as a fuel.
What do thermoacidophilic archaebacteria oxidize under aerobic conditions?
Sulphur to sulphuric acid.
What byproduct is formed during the photosynthesis of green sulphur bacteria?
Elemental sulphur.
Can you name some examples of crustose lichens?
Graphis, Haematomma, Lecidia, Rhizocarpon, Strigula.
How are plant viruses categorized?
Depending upon the host, into bacterial viruses, algal viruses, fungal viruses, etc.
Which lichen serves as food for musk ox, Caribou, and reindeer in tundra?
Cladonia rangiferina (Reindeer Moss).
What is the shape of the plant body of lichens?
Thalloid and irregular in shape.
What are the types of photoautotrophic bacteria mentioned?
Green sulphur bacteria.
What substance from Cetraria islandica is used as a laxative?
A mucilaginous substance.
What are spiral bacteria called?
Spirilla.
What provides the reducing power for purple sulfur bacteria?
H2S, which is oxidized anaerobically to sulfate.
What compound obtained from lichens is used in anti-cancer drugs?
Protolochesterinic acid.
What is a characteristic feature of spirilla regarding flagella?
They have one or more flagella at each pole.
Where is sulfur deposited in purple sulfur bacteria?
Intracellularly (extracellularly in Ectothiorhodospira).
Who is known as the father of bacteriology?
Louis Pasteur.
How do lichens respond to pollution?
Some are tolerant while others are sensitive to pollutants.
What is Orchil and what is it used for?
A blue dye obtained from Roccella and Leconara, used to dye woolen articles and silk fabrics.
What do green sulphur bacteria use as an electron donor?
H2S or other reduced inorganic sulphur compounds.
Which component of lichens is involved in sexual reproduction?
Only the fungal component.
What happens when an ascospore germinates and contacts a suitable alga?
It forms a new lichen thallus.
What products can be made from sweet-scented thalli of certain lichens?
Scents, perfumes, dhup, hawan samagris.
What medicinal uses have lichens been known for since ancient times?
To cure fever, jaundice, skin diseases, and epilepsy.
What type of bacteria are chemosynthetic bacteria?
Non-photosynthetic but autotrophic.
What is the composition of the cell wall in archaebacteria?
It is made up of polysaccharides and protein subunits.
What are foliose lichens commonly known as?
Leafy lichens.
What are staphylococci?
An irregular group of many spherical bacteria, including Staphylococcus albus and S. aureus.
What type of lipids are found in the plasma membrane of archaebacteria?
Branched chain lipids (glycerol ether lipids).
Describe the structure of foliose lichens.
They are flat with leaf-like and lobed thallus, generally grayish or brownish in color, spreading out in a horizontal layer.
What happens when the ratio of hydrogen to oxygen is greater than two to one in non-sulfur purple bacteria?
Excess hydrogen is used to reduce CO₂.
What is an example of symbiotic bacteria in humans and animals?
Bacteria inhabiting the intestine.
What is a characteristic of chemosynthetic bacteria regarding energy sources?
They have high specificity with respect to inorganic energy sources.
How many turns of a helix does a spirillum have?
More than one turn.
What are viral particles known as when not inside an infected cell?
Virions.
What can some forms of thermoacidophilic archaebacteria reduce under anaerobic conditions?
Sulphur to hydrogen sulphide.
Where is the elemental sulphur deposited after being formed?
Extracellularly.
In which country are lichens used in confectionery for making chocolates and pastries?
France.
How is the plant body of fruticose lichens attached to the substratum?
With the help of a basal attachment.
Why are methanogenic bacteria considered beneficial?
They are exploited as alternative energy sources.
What does the fungal component provide to the alga in lichens?
Food, water, and minerals.
What types of life forms can viruses infect?
All types, from multicellular to unicellular organisms.
Where is chlorobium chlorophyll located in green sulphur bacteria?
In the invaginations of the cytoplasmic membrane.
Give an example of a diplobacillus.
Corynebacterium diphtheriae.
Can foliose lichens be easily dismantled?
Yes, they can be easily dismantled without damaging the substrates.
What are Gymnocarpeae also known as?
Discolichens (e.g., Parmelia).
Name an example of a streptobacillus.
Bacillus tuberculosis.
What are fruticose lichens commonly known as?
Shrubby lichens.
Describe the structure of fruticose lichens.
They have a well-developed, shrub-like, cylindrical, and branched thallus.
What are Archaebacteria?
A group of single-celled microorganisms that are distinct from bacteria and eukaryotes.
