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4

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.

A. Archaebacteria

B. Cyanobacteria

C. Chrysophytes

D. Dinoflagellates

Correct Answer :

B. Cyanobacteria


Cyanobacteria are aquatic and photosynthetic, i.e., they live in the water, and can manufacture their own food. They are quite small and usually unicellular, though they often grow in colonies large enough to see. They are the first organisms to make the atmosphere aerobic.

Related Questions

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4

The given statements are some characters of a particular group of Kingdom protista.
(i) Most of them are fresh water organisms found in standing water.
(ii) They have a protein rich layer (called pellicle) which makes their body flexible.
(iii) They have two flagella, a short and a long one.
(iv) Though they are photosynthetic in the presence of sunlight, but in the absence of sunlight they behave like heterotrophs by predating on other smaller organisms.
Identify the correct group on the basis of these characters.

A. Protozoans

B. Chrysophytes

C. Slime moulds

D. Euglenoids

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4

In some viruses, RNA is present instead of DNA indicating that

A. their nucleic acid must combine with host DNA before replication.

B. they cannot replicate.

C. there is no hereditary information.

D. RNA can transfer heredity material.

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4

Which of the following is an example of amoeboid protozoans ?

A. Trypanosoma

B. Paramecium

C. Gonyaulax

D. Entamoeba

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4

Which of the following characteristic(s) is used by Whittaker for the classification of organisms ?

A. Mode of nutrition

B. Thallus organisation

C. Phylogenetic relationships

D. All of the above

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4

Chemosynthetic autotrophic bacteria are named so because

A. they oxidize various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production.

B. they oxidize various organic substances and use the released energy for their ATP production.

C. both (a) and (b)

D. none of these

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4

Match the characters given in column I with their examples given in column II.
Column IColumn 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. A-(v) B-(ii) C-(iv) D-(iii) E-(i)

B. A-(iii) B-(i) C-(iv) D-(ii) E-(v)

C. A-(ii) B-(i) C-(iii) D-(v) E-(iv)

D. A-(iii) B-(ii) C-(iv) D-(i) E-(v)

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4

When a moist bread is kept exposed in air, it becomes mouldy and black because

A. spores are present in the water.

B. spores are present in the bread.

C. spores are present in the air.

D. the bread decomposes.

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4

Which statement is not correct for viruses ?

A. Viruses are obligate parasites.

B. Viruses can multiply only when they are inside the living cells.

C. Viruses cannot pass through bacterial filters.

D. Viruses are made up of protein and DNA or RNA (never both DNA and RNA).

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4

The figure given below shows the structure of a bacteriophage. Identify its parts labelled as A, B, C and D. 
img4

A. A - Tail fibres B - Head C - Sheath D - Collar

B. A - Sheath B - Collar C - Head D - Tail fibres

C. A - Head B - Sheath C - Collar D - Tail fibres

D. A - Collar B - Tail fibres C - Head D - Sheath

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4

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.

A. Ascomycetes

B. Phycomycetes

C. Basidiomycetes

D. Deuteromycetes

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4

Read the following statements and answer the question given below
(i) They are saprophytic protists.
(ii) Under suitable conditions, they form an aggregation (called plasmodium) which may grow and spread over several feet.
(iii) During unfavourable conditions, the plasmodium differentiates and forms fruiting bodies bearing spores at their tips.
Which of the following class of protists is being described by the above statements ?

A. Euglenoids

B. Dinoflagellates

C. Slime moulds

D. Protozoans

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4

Bladderwort and Venus fly trap are examples of

A. insectivorous plants

B. parasitic plants

C. N2 rich plants

D. aquatic plants

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4

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.
img5

A. Spores - Reproduction

B. Heterocysts - Nitrogen fixation

C. Pellicle - Recycling of nutrition

D. Mucilaginous sheath - Photosynthesis

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4

Lichens indicate SO2 pollution because they

A. show association between algae and fungi.

B. grow faster than others.

C. are sensitive to SO2.

D. flourish in SO2 rich environment.

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4

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.

A. Only (iii)

B. (i), (iii) and (v)

C. (i), (ii), (iv), and (v)

D. All of the above

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4

Which of the following is/are example(s) of deuteromycetes?

A. Alternaria

B. Colletotrichum

C. Trichoderma

D. All of these

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4

Which one of the following is a characteristic feature of chrysophytes?

A. They are parasitic forms which cause diseases in animals.

B. They have a protein rich layer called pellicle.

C. They have indestructible wall layer deposited with silica.

D. They are commonly called dinoflagellates.

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4

The genetic material of virus includes

A. only RNA.

B. only DNA.

C. RNA and DNA both

D. RNA or DNA i.e. one nucleic acid in a virus.

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4

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?

A. Sac fungi

B. Bracket fungi

C. Imperfect fungi

D. Phycomycetes

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4

Match the class of fungi given in column I with their examples given in column II and choose the correct option
Column-IColumn-II
(Class of fungi)(Examples)
A. AscomycetesI. Rhizopus
B. BasidiomycetesII. Penicillium
C. DeuteromycetesIII. Ustilago
D. PhycomycetesIV. Alternaria

A. A IV, B III, C I, D II

B. A II, B III, C IV, D I

C. A IV, B I, C II, D III

D. A III, B IV, C II, D I

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4

Match column I (Kingdom) with column II (Class) and select the correct options
Column-IColumn-II
(Kingdom)(Class)
A. PlantaeI. Archaebacteria
B. FungiII. Euglenoids
C. ProtistaIII. Phycomycetes
D. MoneraIV. Algae

A. A IV, B III, C II, D I

B. A I, B II, C III, D IV

C. A III, B IV, C II, D I

D. A IV, B II, C III, D I

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4

The bacteria which oxidize various inorganic substances and use the released energy for their ATP production are called _______________.

A. Archaebacteria

B. Heterotrophic bacteria

C. Photosynthetic autotrophic bacteria

D. Chemosynthetic autotrophic bacteria

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4

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? 
img6

A. A

B. B

C. C sheath

D. D tail fibres

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4

Which of the following pair is correctly matched ?

A. Fungi Saprophytic parasitic mode of nutrition.

B. Monera Nuclear membrane is present.

C. Plantae Cell wall is made up of cellulose.

D. Animalia Cell wall is absent.

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4

Which of the following statement is incorrect ?

A. TMV has a double-stranded RNA molecule.

B. Most plant viruses are RNA viruses.

C. The bacteriophage has a double-stranded DNA molecule.

D. Most animal viruses are DNA viruses.

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4

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.

A. Only (i)

B. Both (ii) and (iii)

C. (ii), (iii) and (iv)

D. All of these

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4

The symbiotic association of fungi and algae is called

A. lichen

B. mycorrhiza

C. rhizome

D. endomycorrhiza

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4

Which of the following statements regarding cyanobacteria is incorrect?

A. It is also called blue green algae.

B. They are chemosynthetic autotrophs.

C. It forms blooms in polluted water bodies.

D. It is unicellular, colonial or filamentous, marine or terrestrial bacteria.

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4

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.

A. (ii) and (iii)

B. (ii) and (v)

C. (i), (ii) and (iii)

D. (ii), (iv) and (v)

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4

How many bacteria are produced in four hours if a bacterium divides once in half an hour ?

A. 8

B. 64

C. 16

D. 256