Ustilago causes plant diseases (called smuts) because
they parasitize on cereals.
they lack mycelium.
they develop sooty masses of spores.
their affected parts becomes completely black.
Correct Answer :
D. their affected parts becomes completely black.
Smut disease is caused by Ustilago species of basidiomycetes fungi. It is characterized by formation of black coloured chlamydospores or teleutospores (called smut spores) due to which the affected part becomes black.
Related Questions
Which of the following class of fungi is being described by the given statements ?
(i) They are found in aquatic habitats and on decaying wood in moist and damp places.
(ii) Mycelium is aseptate and coenocytic.
(iii) Asexual reproduction takes place by zoospores (motile) or by aplanospores (non-motile).
(iv) Some common examples are Mucor, Rhizopus and Albugo.
Ascomycetes
Phycomycetes
Basidiomycetes
Deuteromycetes
Ustilago causes plant diseases (called smuts) because
they parasitize on cereals.
they lack mycelium.
they develop sooty masses of spores.
their affected parts becomes completely black.
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
A virus can be considered a living organism because it
responds to touch stimulus
respires
reproduces (inside the host)
can cause disease
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
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.
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
Which scientist classify plants into trees, shrubs and herbs & animals into two groups having red blood cells and without red blood cells?
Aristotle
R. H. Whittaker
D. J. Ivanowsky
W. M. Stanley
Which of the following statements regarding cyanobacteria is incorrect?
It is also called blue green algae.
They are chemosynthetic autotrophs.
It forms blooms in polluted water bodies.
It is unicellular, colonial or filamentous, marine or terrestrial bacteria.
Protists are
single-celled eukaryotes.
multicellular eukaryotes.
single-celled prokaryotes.
single-celled akaryote.
Which of the following pairs comes under the group chrysophytes ?
Diatoms and Euglena
Euglena and Trypanosoma
Diatoms and Desmids
Gonyaulax and Desmids
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 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
Bacteria lack alternation of generation because there is
neither syngamy nor reduction division.
no distinct chromosomes.
no conjugation.
no exchange of genetic material.
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)
The genetic material of virus includes
only RNA.
only DNA.
RNA and DNA both
RNA or DNA i.e. one nucleic acid in a virus.
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.
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.
Which group of fungi is commonly known as imperfect fungi ?
Phycomycetes
Ascomycetes
Basidiomycetes
Deuteromycetes
Refer the given figure of bacteria cell and Nostoc and choose the option which shows correct label for the structure marked as A, B, C, D and E ?
A – Cell wall, B – Cell membrane, C – Heterocyst, D – DNA, E – Mucilagenous sheath
A – Cell wall, B – Cell membrane, C – DNA, D – Heterocyst, E – Mucilagenous sheath
A – Mucilagenous sheath, B – Cell membrane, C – DNA, D – Heterocyst, E – Cell wall
A – Cell membrane, B – Cell wall, C – DNA, D – Heterocyst, E – Mucilagenous sheath
Fungi show asexual reproduction by all of the following kinds of spores except
conidia
oospores
sporangiospores
zoospores
Fungi are filamentous with the exception of X which is unicellular. Identify X.
Yeast
Algae
Bacteria
Lichen
The given figure shows some labelled structure as A, B, C and D. In which structure the protein coat that encloses the nucleic acid is present?
A
B
C sheath
D tail fibres
Which of the following statement is/ are correct for bacteria ?
They are the members of the kingdom monera.
They live in extreme habitats such as hot springs, deserts, snow and deep oceans.
They show the most extensive metabolic diversity.
All of the above
A fungus contains cells with two nuclei from different genomes. The nuclei do not fuse but divide independently and simultaneously as new cells are formed. This fungus belongs to
phycomycetes
zygomycetes
deuteromycetes
basidiomycetes
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
The subunit of capsid is called
core
nucleotide
amino acid
capsomere
Which of the following statement is correct for dinoflagellates flagella ?
A single flagellum lies in the transverse groove between the cell plates.
A single flagellum lies in the longitudinal groove between the cell plates.
Two flagella, one lies longitudinally and the other transversely in a furrow between the wall plates.
Flagella are absent.
Which of the following statement is incorrect ?
TMV has a double-stranded RNA molecule.
Most plant viruses are RNA viruses.
The bacteriophage has a double-stranded DNA molecule.
Most animal viruses are DNA viruses.
Which of the following kingdom does not have nuclear membrane ?
Protista
Fungi
Monera
Plantae