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
Correct Answer :
D. heterotrophic bacteria
The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the heterotrophic bacteria. Lactobacillis bacteria convert milk into curd.
Related Questions
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 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
The figure given below shows the structure of a bacteriophage. Identify its parts labelled as A, B, C and D.
A - Tail fibres B - Head C - Sheath D - Collar
A - Sheath B - Collar C - Head D - Tail fibres
A - Head B - Sheath C - Collar D - Tail fibres
A - Collar B - Tail fibres C - Head D - Sheath
Which one of the following statement is correct for archaea?
Archaea resemble eukaryotes in all respects.
Archaea have some novel features that are absent in other prokaryotes and eukaryotes.
Archaea completely differ from both prokaryotes and eukaryotes.
Archaea completely differ from prokaryotes.
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
Match column I (Kingdom) with column II (Class) and select the correct options
| Column-I | Column-II |
|---|---|
| (Kingdom) | (Class) |
| A. Plantae | I. Archaebacteria |
| B. Fungi | II. Euglenoids |
| C. Protista | III. Phycomycetes |
| D. Monera | IV. Algae |
A IV, B III, C II, D I
A I, B II, C III, D IV
A III, B IV, C II, D I
A IV, B II, C III, D I
Which of the following is not a viral disease ?
AIDS and mumps
Small pox and herpes
Influenza
Cholera
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
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
Which group of fungi is commonly known as imperfect fungi ?
Phycomycetes
Ascomycetes
Basidiomycetes
Deuteromycetes
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
Match the scientists given in column I with their discovery given in column II and choose the correct option.
| Column-I | Column-II |
|---|---|
| (Scientists) | (Discovery) |
| A. Ernst Mayr | I. Discovered Viroids |
| B. Whittaker | II. Gave the name virus |
| C. Pasteur | III. Proposed five kingdom classification |
| D. Diener | IV. Darwin of the 20th century |
A IV, B III, C II, D I
A III, B IV, C II, D I
A II, B III, C IV, D I
A I, B II, C III, D IV
Clamp connection is found in
basidiomycetes
ascomycetes
saccharomycetes
haplomycetes
Which of the following statement(s) is/are correct about class basidiomycetes ?
(i) They are commonly known as imperfect fungi because only the asexual or vegetative phases of these fungi are known.
(ii) They grow in soil, on logs and tree stumps and in living plant bodies as parasites, e.g., rusts and smuts.
(iii) The mycelium is branched and septate.
(iv) Some common members are Agaricus, Ustilago and Puccinia.
Only (i)
Both (ii) and (iii)
(ii), (iii) and (iv)
All of these
Which class of fungi lacks sex organs but the process of plasmogamy is brought about by fusion of two vegetative or somatic cells of different strains or genotypes?
Sac fungi
Bracket fungi
Imperfect fungi
Phycomycetes
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.
Which of the following kingdom does not have nuclear membrane ?
Protista
Fungi
Monera
Plantae
Protists are
single-celled eukaryotes.
multicellular eukaryotes.
single-celled prokaryotes.
single-celled akaryote.
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/ 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
Fungi are filamentous with the exception of X which is unicellular. Identify X.
Yeast
Algae
Bacteria
Lichen
Match column I (containing fungus name) with column II (common name) and choose the correct options.
| Column-I | Column-II |
|---|---|
| (Fungus name) | (Commonly called) |
| A. Puccinia | I. Yeast |
| B. Ustilago | II. Mushroom |
| C. Agaricus | III. Smut fungus |
| D. Saccharomyces | IV. Rust fungus |
A I, B II, C III, D IV
A II, B III, C IV, D I
A III, B IV, C I, D II
A IV, B III, C II, D I
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
Which one single organism or the pair of organisms is correctly assigned to its taxonomic group?
Paramecium and Plasmodium belong to the same kingdom as that of Penicillium.
Lichen is a composite organism formed from the symbiotic association of an alga and a protozoan.
Yeast used in making bread and beer is a fungus.
Nostoc and Anabaena are examples of protista.
Which one of the following is a characteristic feature of chrysophytes?
They are parasitic forms which cause diseases in animals.
They have a protein rich layer called pellicle.
They have indestructible wall layer deposited with silica.
They are commonly called dinoflagellates.
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.
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.
How many bacteria are produced in four hours if a bacterium divides once in half an hour ?
8
64
16
256
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.
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.