Dikaryon formation is the characteristic feature of
ascomycetes and basidiomycetes.
phycomycetes and basidiomycetes.
ascomycetes and phycomycetes.
phycomycetes and zygomycetes.
Correct Answer :
A. ascomycetes and basidiomycetes.
In fungi (ascomycetes and basidiomycetes), kayrogamy is delayed and occurs just before meiosis. In the stage intervening between plasmogamy and karyogamy the cells often contain two nuclei or dikaryons (n + n). Such cells are called dikaryotic cells. The phase is known as dikaryophase.
Related Questions
Read the given statements and answer the question.
(i) It includes unicellular as well as multicellular fungi.
(ii) In multicellular forms hyphae are branched and septate.
(iii) Conidiophore produces conidia (spores) exogenously in chain.
(iv) Sexual spores are ascospores produced endogenously in chain.
(v) Fruiting body is called ascocarp.
Identify the correct class of fungi which have all the given characteristics.
Phycomycetes
Sac fungi
Club fungi
Fungi imperfecti
Mycorrhizae are useful for plants because they
fix atmospheric nitrogen.
enhance absorption of nutrients from the soil.
kill insects and pathogen.
provide resistance against abiotic stresses.
When a moist bread is kept exposed in air, it becomes mouldy and black because
spores are present in the water.
spores are present in the bread.
spores are present in the air.
the bread decomposes.
Select the correct match from the given option.
Occurrence of dikaryotic stage - ascomycetes and basidiomycetes.
Saprophytes - They are autotrophic and absorb soluble organic matter from dead substrates.
Vegetative mean of reproduction in fungi - fragmentation, budding and sporangiophores.
Steps involved in asexual cycle of fungi - plasmogamy, karyogamy and meiosis in zygote resulting in haploid spores.
Which of the following is smallest living cell and can live without oxygen ?
Mycoplasma
Mycorrhiza
Euglena
Trypanosoma
Bacteria are found to be primitive organisms because they
are small, microscopic which are not seen with naked eye.
cause serious diseases to human being, domesticated animals and crop plants.
produce endospores which are very resistant to adverse conditions.
possess incipient nucleus and show amitotic division.
The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the ones categorised as
cyanobacteria
archaebacteria
chemosynthetic autotrophs
heterotrophic bacteria
The given characters are seen in which of the following group?
(i) Unicellular, colonial, filamentous, marine or terrestrial forms.
(ii) The colonies are surrounded by a gelatinous sheath.
(iii) Some can fix atmospheric nitrogen in specialized cells called heterocysts.
(iv) They often form blooms in water bodies.
Archaebacteria
Cyanobacteria
Chrysophytes
Dinoflagellates
Which of the following statement(s) is/are correct ?
(i) Reproduction in fungi can take place by vegetative means fragmentation, fission and budding.
(ii) Fusion of two nuclei is called plasmogamy.
(iii) Fusion of protoplasms between two motile or nonmotile gametes is called karyogamy.
(iv) Meiosis in zygote results in diploid spores.
Only (i)
Both (ii) and (iii)
(ii), (iii) and (iv)
All of these
Read the following statements and answer the question.
(i) Some members are saprophytes or parasites while a large number of them are decomposers of litter and help in mineral cycling.
(ii) They reproduce only by asexual spores known as conidia.
(iii) Mycelium is septate and branched.
(iv) Alternaria, Colletotrichum and Trichoderma are examples of this class.
Which of the following class of fungi is being described by the above statements ?
Phycomycetes
Deuteromycetes
Basidiomycetes
Ascomycetes
Fungi are filamentous with the exception of X which is unicellular. Identify X.
Yeast
Algae
Bacteria
Lichen
Identify the basis of classification of fungi into phycomycetes, ascomycetes, basidiomycetes and deuteromycetes.
i. Fruiting bodies
ii. Nature of habitat
iii. Morphology of mycelium
iv. Mode of spore formation
i & ii only
ii & iii only
i, ii, & iv only
All of these
Chemosynthetic autotrophic bacteria are named so because
they oxidize various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production.
they oxidize various organic substances and use the released energy for their ATP production.
both (a) and (b)
none of these
Which statement is not correct for viruses ?
Viruses are obligate parasites.
Viruses can multiply only when they are inside the living cells.
Viruses cannot pass through bacterial filters.
Viruses are made up of protein and DNA or RNA (never both DNA and RNA).
Choose the correct names of the different bacteria given below according to their shapes.
A – Cocci, B – Bacilli, C – Spirilla, D – Vibrio
A – Bacilli, B – Cocci, C – Spirilla, D – Vibrio
A – Spirilla, B – Bacilli, C – Cocci, D – Vibrio
A – Spirilla, B – Vibrio, C – Cocci, D – Bacilli
Bladderwort and Venus fly trap are examples of
insectivorous plants
parasitic plants
N2 rich plants
aquatic plants
Which of the following pair is not correctly matched ?
Anabaena Cyanobacteria
Amoeba Protozoa
Gonyaulax Dinoflagellates
Albugo Chrysophytes
Which of the following are the characters of dinoflagellates?
(i) They are planktonic golden yellow algae with soap box like structure.
(ii) They are marine red biflagellated protista.
(iii) They appear yellow, green, brown, blue and red in colour.
(iv) They are biflagellated organisms with pellicle.
(v) They are saprophytic (or) parasitic unicellular forms.
(ii) and (iii)
(ii) and (v)
(i), (ii) and (iii)
(ii), (iv) and (v)
Which of the following is used extensively in biochemical and genetic work ?
Agaricus
Alternaria
Neurospora
Mucor
The symbiotic association of fungi and algae is called
lichen
mycorrhiza
rhizome
endomycorrhiza
Bacteria were regarded to be plants because
some of them are green in colour.
they are present every where.
some of them cannot move.
they have a rigid cell wall.
How many bacteria are produced in four hours if a bacterium divides once in half an hour ?
8
64
16
256
T. O. Diener discovered a new infectious agent that was smaller than viruses and have the following characteristics.
(i) It causes potato spindle tuber disease.
(ii) It has free RNA.
(iii) Molecular weight of RNA is low.
Identify the infections agent.
Viruses
Viroids
Virion
Mycoplasma
Which of the following statement is not correct for methanogens?
They are archaebacteria.
They live in marshy areas.
Methane is their preferred carbon source.
They are present in guts of several ruminant animals (cow, buffaloes) and produce biogas (CH4) from the dung of these animals.
Which of the following statement(s) is/are correct about ascomycetes ?
(i) Neurospora, which is used in biochemical and genetic work is a member of this class.
(ii) They are mostly multicellular, e.g., Yeast, or rarely unicellular, e.g., Penicillium.
(iii) They are saprophytic, decomposers, parasitic or coprophilous.
(iv) Some examples are Aspergillus, Claviceps and Neurospora.
Both (i) and (ii)
Only (ii)
(i), (iii) and (iv)
All of these
Clamp connection is found in
basidiomycetes
ascomycetes
saccharomycetes
haplomycetes
A specimen of fungus is brought by a student for identification. Upon close examination, he discovered that its hyphae are completely septate and it has gills on the underside of the pileus. To which fungal group does it most likely belong ?
Basidiomycetes
Zygomycetes
Ascomycetes
Chytrids
Lichens indicate SO2 pollution because they
show association between algae and fungi.
grow faster than others.
are sensitive to SO2.
flourish in SO2 rich environment.
Which of the following processes involved in the reproduction of protists ?
Binary fission and budding
Cell fusion and zygote formation
Spore formation and cyst formation
All of the above
Choose the correct statements (i v) regarding mycoplasma
(i) Mycoplasma has no cell wall.
(ii) Mycoplasma is the smallest living organism.
(iii) Mycoplasma cannot survive without O2.
(iv) Mycoplasma are pathogenic in animals and plants.
(v) A sort of sexual reproduction occurs in bacterium by adopting a primitive DNA transfer from one bacterium to the other.
Only (iii)
(i), (iii) and (v)
(i), (ii), (iv), and (v)
All of the above