The given figure shows the structure of filamentous blue green algae, Nostoc with a structure marked as X. Select the option which shows the correct identification of the X with its feature.
Spores - Reproduction
Heterocysts - Nitrogen fixation
Pellicle - Recycling of nutrition
Mucilaginous sheath - Photosynthesis
Correct Answer :
B. Heterocysts - Nitrogen fixation
Heterocysts are pale-yellow, thick-walled cells that are capable of nitrogen fixation and therefore play a major part in the nitrogen cycle.
Related Questions
Fungi are filamentous with the exception of X which is unicellular. Identify X.
Yeast
Algae
Bacteria
Lichen
Dikaryon formation is the characteristic feature of
ascomycetes and basidiomycetes.
phycomycetes and basidiomycetes.
ascomycetes and phycomycetes.
phycomycetes and zygomycetes.
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
Plasmogamy is the fusion of
two haploid cells including their nuclei.
two haploid cells without nuclear fusion.
sperm and egg.
sperm and two polar nuclei.
Clamp connection is found in
basidiomycetes
ascomycetes
saccharomycetes
haplomycetes
Which of the following group of kingdom protista is being described by the statements given below ?
(i) This group includes diatoms and golden algae.
(ii) They are microscopic and float passively in water currents (plankton).
(iii) Most of them are photosynthetic.
(iv) They have deposits in their habitat; this accumulation over billion of years is referred to as diatomaceous earth.
Dinoflagellates
Chrysophytes
Euglenoids
Slime moulds
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
Bacteria and yeast are similar in all the following features except that
both are unicellular.
both are prokaryotes.
both are capable of causing fermentation.
both produce spores.
Match the class of fungi given in column I with their examples given in column II and choose the correct option
| Column-I | Column-II |
|---|---|
| (Class of fungi) | (Examples) |
| A. Ascomycetes | I. Rhizopus |
| B. Basidiomycetes | II. Penicillium |
| C. Deuteromycetes | III. Ustilago |
| D. Phycomycetes | IV. Alternaria |
A IV, B III, C I, D II
A II, B III, C IV, D I
A IV, B I, C II, D III
A III, B IV, C II, D I
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.
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
Which of the following is/are example(s) of deuteromycetes?
Alternaria
Colletotrichum
Trichoderma
All of these
Which of the following is not a viral disease ?
AIDS and mumps
Small pox and herpes
Influenza
Cholera
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
Why food can be kept for a longer time in cold house than in normal conditions ? Because,
insect cannot enter.
bacterial multiplication stops.
bacterial multiplication is reduced.
there is plasmolysis at low temperature.
Which of the following pairs comes under the group chrysophytes ?
Diatoms and Euglena
Euglena and Trypanosoma
Diatoms and Desmids
Gonyaulax and Desmids
Match the characters given in column I with their examples given in column II.
| Column I | Column II |
|---|---|
| A. Long slender thread | (i) Lichen like structures |
| B. Association of fungi with | (ii) Mycorrhiza roots of higher plants |
| C. Parasitic fungi on mustard | (iii) Neurospora |
| D. Fungi extensively used in | (iv) Albugo biochemical and genetic work |
| E. An association in which | (v) Hyphae algal component is called phycobiont |
A-(v) B-(ii) C-(iv) D-(iii) E-(i)
A-(iii) B-(i) C-(iv) D-(ii) E-(v)
A-(ii) B-(i) C-(iii) D-(v) E-(iv)
A-(iii) B-(ii) C-(iv) D-(i) E-(v)
How many organisms in the list given below are autotrophs? Lactobacillus, Nostoc, Chara, Nitrosomonas, Nitrobacter, Streptomyces, Saccharomyces, Trypanosomes, Porphyra, Wolffia
Four
Five
Six
Three
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
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 of the following groups of protozoan is not correctly matched with its feature?
Amoeboid - Marine forms have silica shells on their surface.
Flagellated - Either free living or parasitic.
Ciliated - Actively moving organisms due to presence of cilia.
Sporozoans - Move and capture their prey with the help of false feet.
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.
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.
Bladderwort and Venus fly trap are examples of
insectivorous plants
parasitic plants
N2 rich plants
aquatic plants
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 of the following characteristic(s) is used by Whittaker for the classification of organisms ?
Mode of nutrition
Thallus organisation
Phylogenetic relationships
All of the above
Consider the following statements with respect to characteristic features of the kingdom.
(i) In animalia, the mode of nutrition is autotrophic.
(ii) In monera, the nuclear membrane is present.
(iii) In protista, the cell type is prokaryotic.
(iv) In plantae, the cell wall is present.
Of the above statements, which one is correct ?
(i) only
(ii) only
(iii) only
(iv) only
Fungi show asexual reproduction by all of the following kinds of spores except
conidia
oospores
sporangiospores
zoospores
Protista includes
unicellular eukaryotes with well-defined nucleus only.
unicellular prokaryotes with membrane bound organelles.
unicellular eukaryotes with well-defined nucleus and membrane bound organelles.
both unicellular and multicellular eukaryotes with welldefined nucleus and membrane bound organelles.