In some viruses, RNA is present instead of DNA indicating that
their nucleic acid must combine with host DNA before replication.
they cannot replicate.
there is no hereditary information.
RNA can transfer heredity material.
Correct Answer :
D. RNA can transfer heredity material.
Viruses are defined as infectious nucleoproteins. A complete virus particle is called virion whose main function is to deliver its DNA or RNA gesnome into the host cell, so that genome can be expressed by the host cell. In a particular virus either DNA or RNA is genetic material, never both are present in a virus. Hence, viruses are:
(i) Double stranded DNA or ds DNA - Hepatitis B
(ii) Single stranded DNA or ss DNA - coliphage
(iii) Double stranded RNA or ds RNA - Reo virus, wound Tumor virus
(iv) Single stranded RNA or ss RNA - Tobacco mosaic virus (TMV)
Related Questions
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 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.
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 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 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 bacteria which oxidize various inorganic substances and use the released energy for their ATP production are called _______________.
Archaebacteria
Heterotrophic bacteria
Photosynthetic autotrophic bacteria
Chemosynthetic autotrophic bacteria
Which of the following is smallest living cell and can live without oxygen ?
Mycoplasma
Mycorrhiza
Euglena
Trypanosoma
Which of the following is an example of amoeboid protozoans ?
Trypanosoma
Paramecium
Gonyaulax
Entamoeba
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.
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
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
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.
Match the terms given in column-I with their examples given in column-II and choose the correct option
| Column-I | Column-II |
|---|---|
| (Terms) | (Examples) |
| A. Ascus | I. Spirulina |
| B. Basidium | II. Penicillium |
| C. Protista | III. Agaricus |
| D. Cyanobacteria | IV. Euglena |
| E. Animalia | V. Sponges |
A II, B III, C IV, D V, E I
A I, B II, C III, D V, E IV
A II, B V, C III, D I, E IV
A II, B III, C IV, D I, E V
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.
In some viruses, RNA is present instead of DNA indicating that
their nucleic acid must combine with host DNA before replication.
they cannot replicate.
there is no hereditary information.
RNA can transfer heredity material.
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.
Match the class of fungi given in column-I with their common name given in column-II and select the correct option.
| Column-I | Column-II |
|---|---|
| (Class of fungi) | (Common name) |
| A. Phycomycetes | I. Sac fungi |
| B. Ascomycetes | II. Algal fungi |
| C. Basidiomycetes | III. Fungi imperfecti |
| D. Deuteromycetes | IV. Club fungi |
A II, B I, C IV, D III
A II, B IV, C I, D III
A IV, B I, C II, D III
A IV, B III, C II, D I
Assume that two normal hyphal cells of different fungal mating types unite. After a period of time, the cell between these cells will dissolve producing a
mycelium
fruiting body
zygote
dikaryotic cell, which is also heterokaryotic
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
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.
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
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.
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
Which of the following statement is correct for both bluegreen algae and bacteria ?
Both show anaerobic respiration.
Both have chlorophyll pigment.
Both are devoid of true nucleus.
None of the above
Which of the following is/are example(s) of deuteromycetes?
Alternaria
Colletotrichum
Trichoderma
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
How many bacteria are produced in four hours if a bacterium divides once in half an hour ?
8
64
16
256
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
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
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