Biological Classification Chapter-Wise Test 17

Correct answer Carries: 4.

Wrong Answer Carries: -1.

Which group of fungi is commonly known as “imperfect fungi” because only its asexual or vegetative phases are known?

Ascomycetes
Phycomycetes
Deuteromycetes
Basidiomycetes
3

Deuteromycetes are called imperfect fungi because only their asexual or vegetative phases are known. When their sexual forms are discovered, they are moved to the fungal classes to which they correctly belong.

Which of the following organisms has a protein-rich pellicle instead of a cell wall?

Diatom
Euglena
Nostoc
Rhizopus
2

Euglenoids such as Euglena lack a cell wall. Instead, they possess a protein-rich layer called the pellicle, which makes the body flexible.

Which group of protozoans moves and captures prey by forming pseudopodia?

Amoeboid protozoans
Flagellated protozoans
Ciliated protozoans
Sporozoans
1

Amoeboid protozoans move and capture their prey by extending pseudopodia, or false feet. Amoeba is a common example of this group.

What is the main mode of reproduction in bacteria?

Budding
Fragmentation
Fission
Formation of gametes
3

Bacteria reproduce mainly by fission. Under unfavourable conditions, some bacteria may also produce spores, and a primitive type of DNA transfer may occur between bacterial cells.

Which statement correctly describes the genetic material of viruses?

Every virus contains both RNA and DNA.
A virus contains either RNA or DNA, but never both.
Viruses contain only proteins and no genetic material.
All viruses contain only double-stranded DNA.
2

Viruses contain genetic material in the form of either RNA or DNA. No virus contains both RNA and DNA. The nucleic acid is enclosed by a protein coat called the capsid.

Which organism can multiply rapidly and cause red tides in the sea?

Euglena
Nostoc
Gonyaulax
Paramoecium
3

Red dinoflagellates such as Gonyaulax may multiply so rapidly that the sea appears red. Toxins released by these large populations may kill marine animals such as fishes.

Which fungus is mentioned as a source of antibiotics?

Penicillium
Rhizopus
Puccinia
Ustilago
1

Penicillium is mentioned as a source of antibiotics. In contrast, Puccinia causes wheat rust, while Rhizopus is commonly known as bread mould.

Which group includes organisms whose cell walls are embedded with silica?

Dinoflagellates
Diatoms
Euglenoids
Slime moulds
2

Diatom cell walls form two thin, overlapping shells and are embedded with silica, making them indestructible. Their accumulated cell-wall deposits form diatomaceous earth.

Which of the following statements about cyanobacteria is incorrect?

They have chlorophyll a and are photosynthetic autotrophs.
They possess a well-defined nucleus.
Some can fix atmospheric nitrogen in heterocysts.
They may be unicellular, colonial or filamentous.
2

Cyanobacteria are prokaryotic members of Kingdom Monera and therefore do not possess a well-defined nucleus. Some forms, such as Nostoc and Anabaena, fix atmospheric nitrogen in specialised cells called heterocysts.

Which of the following is a characteristic of Mycoplasma?

It possesses a rigid cell wall.
It is among the smallest living cells known.
It is a photosynthetic autotroph.
It has a cell wall containing peptidoglycan.
2

Mycoplasma completely lacks a cell wall and includes the smallest living cells known. These organisms can also survive without oxygen, and many are pathogenic in animals and plants.

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