Biological Classification Chapter-Wise Test 10

Correct answer Carries: 4.

Wrong Answer Carries: -1.

A composite organism contains an autotrophic partner that prepares food and a heterotrophic partner that provides shelter and absorbs water and minerals. Which additional observation would support its identification?

It grows abundantly in polluted areas.
It is generally absent from polluted areas.
Both partners possess chlorophyll.
It consists of a fungus and a plant root.
2

The organism is a lichen. Its algal phycobiont prepares food, while its fungal mycobiont provides shelter and absorbs water and mineral nutrients. Lichens do not grow in polluted areas and therefore serve as pollution indicators.

A virus infecting a plant is compared with a bacteriophage. Which combination of genetic material is most consistent with the chapter?

Plant virus—generally single-stranded RNA; bacteriophage—usually double-stranded DNA
Plant virus—always double-stranded DNA; bacteriophage—protein only
Plant virus—both DNA and RNA; bacteriophage—single-stranded RNA only
Plant virus—no nucleic acid; bacteriophage—both DNA and RNA
1

Plant viruses generally possess single-stranded RNA, whereas bacteriophages are usually double-stranded DNA viruses. A virus contains either RNA or DNA as its genetic material, never both.

A fungus grows on moist bread, has aseptate and coenocytic mycelium, and produces motile or non-motile spores inside sporangia. To which class does it belong?

Ascomycetes
Basidiomycetes
Deuteromycetes
Phycomycetes
4

Phycomycetes possess aseptate, coenocytic mycelium. Their motile zoospores or non-motile aplanospores are produced endogenously inside sporangia. Rhizopus is an example.

An organism stores reserve food as glycogen and oil droplets, obtains nutrients by absorption and generally possesses a filamentous body. In which kingdom should it be placed?

Plantae
Animalia
Fungi
Monera
3

These features indicate Kingdom Fungi. Fungi are absorptive heterotrophs, generally have filamentous bodies and store reserve food as glycogen and oil droplets.

A prokaryotic colony contains chlorophyll a, is surrounded by a gelatinous sheath and sometimes forms specialised nitrogen-fixing cells. Which group is being described?

Cyanobacteria
Dinoflagellates
Euglenoids
Diatoms
1

Cyanobacteria are photosynthetic prokaryotes containing chlorophyll a. Their colonies commonly possess a gelatinous sheath, and forms such as Nostoc and Anabaena may contain nitrogen-fixing heterocysts.

An infectious agent associated with potato spindle tuber disease is smaller than viruses and lacks a protein coat. What is its chemical nature?

Abnormally folded protein
Free RNA of low molecular weight
Double-stranded DNA enclosed by a capsid
RNA and DNA enclosed together by a protein coat
2

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

A fungus produces asexual spores externally on conidiophores and sexual spores internally within sac-like structures. Which pairing is correct?

Basidiomycetes—zoospores and ascospores
Phycomycetes—conidia and basidiospores
Ascomycetes—conidia and ascospores
Deuteromycetes—ascospores and basidiospores
3

Ascomycetes produce conidia exogenously on conidiophores. Their sexual ascospores are produced endogenously inside sac-like asci, which may be arranged in ascocarps.

An organism is multicellular, lacks a cell wall, ingests food and digests it internally. Which additional feature is expected?

Presence of chlorophyll a
Absorptive nutrition through hyphae
A cellulose cell wall
Reserve food stored as glycogen or fat
4

The organism belongs to Kingdom Animalia. Animals are multicellular heterotrophs without cell walls, obtain food by ingestion and internal digestion, and store reserve food as glycogen or fat.

A microorganism oxidises nitrites and ammonia, uses the released energy for ATP production and contributes to nutrient cycling. How should it be classified?

Photosynthetic dinoflagellate
Saprophytic slime mould
Chemosynthetic autotrophic bacterium
Parasitic protozoan
3

Chemosynthetic autotrophic bacteria oxidise inorganic substances such as nitrites and ammonia. They use the released energy for ATP production and help recycle nutrients such as nitrogen, phosphorus, iron and sulphur.

An aquatic unicellular eukaryote has no cell wall, possesses a flexible protein-rich covering and has one short and one long flagellum. How does it obtain food when sunlight is absent?

It preys on smaller organisms.
It oxidises inorganic substances.
It absorbs nutrients through fungal hyphae.
It fixes atmospheric nitrogen in heterocysts.
1

The organism is a euglenoid. Euglenoids have a protein-rich pellicle and two unequal flagella. They photosynthesise in sunlight but behave as heterotrophs by preying on smaller organisms when sunlight is unavailable.

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