Biological Classification Chapter-Wise Test 8

Correct answer Carries: 4.

Wrong Answer Carries: -1.

A fungus has branched, septate mycelium, produces conidia externally and forms sexual spores inside sac-like structures. Which group and common name correctly identify it?

Phycomycetes—algal fungi
Ascomycetes—sac fungi
Basidiomycetes—imperfect fungi
Deuteromycetes—club fungi
2

The fungus belongs to Ascomycetes, commonly called sac fungi. Their asexual conidia are produced externally on conidiophores, whereas sexual ascospores are formed inside sac-like asci.

In a lichen, partner X prepares food while partner Y provides shelter and absorbs water and minerals. Which additional observation would support the identification of this association?

It grows abundantly in highly polluted areas.
X is the fungal mycobiont.
Y is the fungal mycobiont, and the association is sensitive to pollution.
Both partners are heterotrophic fungi.
3

In lichens, the algal phycobiont prepares food, while the fungal mycobiont provides shelter and absorbs water and mineral nutrients. Lichens do not grow in polluted areas and therefore serve as pollution indicators.

An organism is heterotrophic, has a cell wall and obtains nutrients by absorption. Most members are filamentous, but some are unicellular. In which kingdom should it be placed?

Monera
Protista
Fungi
Animalia
3

Kingdom Fungi includes absorptive heterotrophs with cell walls. Most fungi are filamentous and multicellular, but yeasts are unicellular exceptions.

A very small prokaryotic cell survives without oxygen and causes disease in plants and animals. Which structural observation would identify it as Mycoplasma?

It possesses stiff cellulose plates.
It completely lacks a cell wall.
It possesses a membrane-bound nucleus.
It has a silica-containing shell.
2

Mycoplasma completely lack a cell wall. They are the smallest living cells known, can survive without oxygen and include pathogenic forms that cause diseases in plants and animals.

An organism belongs to Monera but survives in an extremely salty area because its cell wall differs from that of other bacteria. How should it be classified?

A halophilic archaebacterium
A methanogenic eubacterium
A photosynthetic protist
A thermoacidophilic fungus
1

Archaebacteria living in extremely salty habitats are called halophiles. Their unusual cell-wall structure helps them survive in these extreme environmental conditions.

A saprophytic protist moves over decaying leaves and twigs, engulfing organic material. Under favourable conditions, what structure can it form?

An ascocarp containing asci
A basidiocarp containing basidia
A filament containing heterocysts
A plasmodium that may spread over several feet
4

The organism is a slime mould. Slime moulds are saprophytic protists that engulf organic material, and under suitable conditions they form a plasmodium that may spread over an area of several feet.

An infectious agent associated with potato spindle tuber disease consists of free, low-molecular-weight RNA and has no protein coat. Which conclusion is correct?

It is a virus crystallised by W. M. Stanley.
It is a prion made of abnormal protein.
It is a viroid discovered by T. O. Diener.
It is a bacteriophage containing double-stranded DNA.
3

The agent is a viroid. T. O. Diener discovered it while studying potato spindle tuber disease. Viroids consist of free RNA of low molecular weight and lack the protein coat found in viruses.

A parasitic protozoan possesses flagella and causes sleeping sickness. Which organism and protozoan group are correctly matched?

Trypanosoma—flagellated protozoan
Plasmodium—sporozoan
Paramoecium—amoeboid protozoan
Entamoeba—ciliated protozoan
1

Trypanosoma is a parasitic flagellated protozoan that causes sleeping sickness. Plasmodium belongs to the sporozoans, while Paramoecium is a ciliated protozoan.

Two aquatic protists each possess two flagella. Organism X has one longitudinal and one transverse flagellum, whereas organism Y has one short and one long flagellum. Which identification is correct?

X—euglenoid; Y—dinoflagellate
X—diatom; Y—slime mould
X—dinoflagellate; Y—euglenoid
X—amoeboid protozoan; Y—ciliated protozoan
3

Dinoflagellates possess one longitudinal and one transverse flagellum. Euglenoids also possess two flagella, but these are described as one short and one long.

An aquatic microscopic organism is photosynthetic, floats passively with plankton and possesses indestructible silica-containing walls. Which ecological conclusion follows?

It is a major decomposer of forest litter.
It is a dinoflagellate that necessarily causes red tides.
It is a methanogen involved in biogas production.
It is a diatom and is among the chief producers in oceans.
4

The organism is a diatom, a photosynthetic chrysophyte that forms part of the plankton. Diatoms are described as the chief producers in oceans, and their accumulated silica-rich walls form diatomaceous earth.

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