NEET Biology Biological Classification MCQs Set 21

Answer: (b) Three

Explanation:
1. Euglena, Chlorella and Physarum are unicellular or acellular eukaryotes of Protista.
2. Nostoc, Spirulina and Azotobacter are prokaryotes (Monera), and Azolla is a fern (Plantae).

Teacher's Note:
1. So three belong to Protista.
2. Slime moulds like Physarum are placed in Protista.

Answer: (b) Puccinia - Red rust of tea

Explanation:
1. Puccinia causes black rust of wheat, whereas red rust of tea is caused by the alga Cephaleuros.

Teacher's Note:
1. The other three pairs are correctly matched.
2. Puccinia is a basidiomycete.

Answer: (d) All of the above

Explanation:
1. Heterocysts are thick-walled cells of filamentous cyanobacteria like Nostoc and Anabaena.

Teacher's Note:
1. They lack photosystem II, so they do not photosynthesise, and they fix atmospheric nitrogen.
2. All three statements are correct.

Answer: (d) Most of them have two flagella, one lies longitudinally and the other transversely in a furrow

Explanation:
1. Two flagella, one longitudinal and one transverse in a furrow, describe dinoflagellates and not chrysophytes.

Teacher's Note:
1. Chrysophytes include diatoms and golden algae, and they are microscopic and float passively.
2. Diatoms have siliceous walls that form diatomaceous earth.

Answer: (d) Symbiotic association between fungi and roots of higher plants

Explanation:
1. Mycorrhiza is a mutualistic association between a fungus and the roots of a higher plant.

Teacher's Note:
1. The fungus helps in absorption of phosphorus and the plant gives food.
2. Association of algae and fungi is called lichen.

Answer: (c) Capsomere

Explanation:
1. The protein coat of a virus is the capsid, which is made of many small units called capsomeres.

Teacher's Note:
1. The capsid protects the nucleic acid.
2. Capsomeres decide the symmetry of the virus.

Answer: (b) Basidiomycetes

Explanation:
1. Clamp connections occur in the dikaryotic hyphae of Basidiomycetes and help to maintain the dikaryotic condition.

Teacher's Note:
1. They distribute the nuclei equally to the daughter cells.
2. Ascomycetes form septate hyphae without clamps.

Answer: (a) Unicellular eukaryotes

Explanation:
1. All protists are unicellular eukaryotes with a well-defined nucleus.

Teacher's Note:
1. Prokaryotes belong to Monera.
2. Chrysophytes, dinoflagellates, euglenoids, slime moulds and protozoans are protists.

Answer: (c) Air pollution

Explanation:
1. Lichens are very sensitive to sulphur dioxide and do not grow in polluted air.

Teacher's Note:
1. Their presence shows clean air.
2. They are a symbiosis of an alga and a fungus.

Answer: (b) Ammonia or ammonium compounds into nitrates

Explanation:
1. Nitrosomonas converts ammonia to nitrite, and Nitrobacter converts nitrite to nitrate.

Teacher's Note:
1. Conversion of nitrate to nitrogen is denitrification.
2. Nitrogen is fixed by different bacteria.

Answer: (b) Mycoplasma

Explanation:
1. Mycoplasma is the smallest living cell and has no cell wall.

Teacher's Note:
1. It can survive without oxygen and is pleomorphic.
2. It causes diseases in plants and animals.

Answer: (c) Oscillatoria

Explanation:
1. Hormogonia are small fragments of a filament of the cyanobacterium Oscillatoria that grow into new filaments.

Teacher's Note:
1. Ulothrix and Spirogyra are green algae.
2. Chlamydomonas is a unicellular alga.

Answer: (d) Agaricus and Claviceps, respectively

Explanation:
1. Agaricus (mushroom) is a basidiomycete that forms a basidiocarp, and Claviceps is an ascomycete that forms an ascocarp.

Teacher's Note:
1. Alternaria is a deuteromycete and has no sexual fruiting body.
2. Ustilago (smut) forms no basidiocarp.

Answer: (b) Dinoflagellates - soap box like cell walls

Explanation:
1. Soap box like walls with two overlapping shells belong to diatoms.

Teacher's Note:
1. Dinoflagellates have stiff cellulose plates on the outer surface.
2. The other three matches are correct.

Answer: (b) Protista

Explanation:
1. Protista forms a link between monera, plants, fungi and animals, so its boundaries are not well defined.

Teacher's Note:
1. Some protists are photosynthetic and some are consumers.
2. This makes the kingdom a connecting group.

Answer: (c) Chlorophyll a

Explanation:
1. Both have chlorophyll a and carry out oxygenic photosynthesis.

Teacher's Note:
1. Cyanobacteria have 70S ribosomes and a peptidoglycan wall.
2. Green plants cannot fix nitrogen.

Answer: (c) Somatogamy

Explanation:
1. In smut fungi like Ustilago, sexual reproduction takes place by fusion of two vegetative (somatic) cells, called somatogamy.

Teacher's Note:
1. Conidia are asexual spores.
2. Gametangial contact and copulation are seen in Phycomycetes.

Answer: (d) Cytoplasm

Explanation:
1. The cell envelope has three layers: glycocalyx, cell wall and plasma membrane.

Teacher's Note:
1. The cytoplasm lies inside the envelope.
2. The glycocalyx can be a loose slime layer or a thick capsule.

Answer: (b) Viruses

Explanation:
1. Viruses are non-cellular and are not placed in any of the five kingdoms.

Teacher's Note:
1. Bacteria are in Monera, and slime moulds and protozoans are in Protista.
2. Viruses are classified separately.

Answer: (b) Unfavourable conditions

Explanation:
1. Slime moulds form fruiting bodies with spores under unfavourable conditions.

Teacher's Note:
1. The spores have true walls and are dispersed by air currents.
2. In favourable conditions they feed as plasmodium.

Answer: (c) Agaricus - Vinegar

Explanation:
1. Vinegar is made by Acetobacter, whereas Agaricus is an edible mushroom.

Teacher's Note:
1. Yeast ferments sugar to ethanol, Streptomyces gives streptomycin, and methanogens form biogas.
2. Acetobacter oxidises ethanol to acetic acid.