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Q1. Difference between virus and viroid is

• Protein coat absent in viroid but present in virus
• Low molecular weight RNA present in virus but absent in viroid
• Both a and b
• None of the above

Solution

In viruses, the genetic material can be RNA or DNA which is enclosed by the capsid. In viroids, the genetic material is RNA which is free and not enclosed by any protein coat.

Q2. Which one does not possess nucleic acid? 

• Prion
• Viroid
• Virus
• Mycoplasma

Solution

Prions are abnormally folded proteins which are made of amino acids.   Nucleic acids are used in the reproduction of DNA and play a role in protein synthesis, but they are not directly embedded into the protein.   Therefore, prions do not contain any nucleic acid (or genetic information) within them. 

Q3. Who proposed Contagium vivum fluidum?

• D. J. Ivanowsky
• M. W. Beijerinck
• A. Roxberg
• Virchow

Solution

M. W. Beijerinck demonstrated that the extract of infected tobacco plant can infect the healthy plant. He named this extract as Contagium vivum fluidum.

Q4. Single-celled eukaryotes are included in

• Monera
• Protista
• Fungi
• Archaea

Solution

Unicellular eukaryotes (except some unicellular algae and fungi) are grouped under kingdom Protista. Protists are considered as the phylogenetic link between kingdom Monera and multicellular eukaryotic organisms.

Q5. Virus was placed in

• Monera
• Protista
• Fungi
• None of these

Solution

Viruses do not belong to any kingdom in biological classification. Viruses are inert when outside the living cell. They are active and can replicate only when they infect the host cell.

Q6. Cauliflower mosaic virus contains 

• ssRNA
• dsRNA
• dsDNA
• ssDNA

Solution

Cauliflower mosaic virus (CMV) also called caulimovirus contains double-stranded (ds) DNA. 

Q7. Lichens are a well-known combination of an alga and a fungus, where the fungus has

• An epiphytic relationship with the alga
• A parasitic relationship with the alga
• A symbiotic relationship with the alga
• A saprophytic relationship with the alga

Solution

Lichens are a permanent symbiotic association between mycobiont, i.e. the fungal component, and phycobiont, i.e. the algal component.

Q8. Which of the following is a prokaryote?

• Amoeba
• Spirogyra
• Bacteria
• Chlamydomonas

Solution

Bacteria belong to kingdom Monera, and it is a prokaryote. A prokaryote does not have membrane-bound cell organelles.

Q9. When fungi feed on dead organic matter, they are known as

• Dimorphic
• Parasites
• Saprophytes
• None of these

Solution

Fungi are saprophytes. They absorb organic constituents as their food from dead and decaying matter.

Q10. Desmids are also called

• Blue-green algae
• Slime moulds
• Mycoplasma
• Golden algae

Solution

Pigment fucoxanthin present in desmids imparts a golden-brown colour. Hence, they are also called golden algae.

Q11. Interferons are 

• Antiviral proteins
• Antibacterial proteins
• Anticancer proteins
• Complex proteins

Solution

Interferons are anti-viral, regulatory glycoproteins which are produced in virus-infected cells for defence. They are non-antigenic proteins weighing 2000 Da. They were discovered by Isaacs and Lindenmann in 1957. These interferons induce formation of certain enzymes which suppress viral multiplication in host cells and protect the host from further viral reinfection. 

Q12. Fungi are always

• Heterotrophs
• Saprotrophs
• Parasites
• Autotrophs

Solution

Fungi are heterotrophs. They can be saprophytic, parasitic or symbiotic.

Q13. Sexual reproduction is absent in

• Ascomycetes
• Deuteromycetes
• Basidiomycetes
• Phycomycetes

Solution

Deuteromycetes is a group of fungi. In them, the sexual reproduction is either absent or unknown. As and when the mode of sexual reproduction was known, the fungi were moved to either ascomycetes or basidiomycetes. Deuteromycetes reproduce asexually by producing spores called conidia.

Q14. Red tide is caused by

• Noctiluca
• Gymnodinium
• Gonyaulax
• All of these

Solution

Noctiluca, Gymnodinium and Gonyaulax are dinoflagellates. Due to their rapid multiplication, the sea appears red which is known as red tide.

Q15. Which of the following is not the locomotory organ of protozoa?

• Cilia
• Flagella
• Parapodia
• Pseudopodia

Solution

In protozoans, locomotion occurs either by pseudopodia, cilia or flagella. Example: Amoeba has pseudopodia, paramoecium locomotes by cilia and trypanosome has flagella as their locomotory organs.

Q16. The shape of the cocci bacteria is

• Rod-shaped
• Spherical
• Comma-shaped
• Spiral

Solution

Bacteria are found in four shapes—cocci (spherical, ovoid shape), bacilli (rod-shaped), spirilla (spiral shaped/coiled) and vibrio (comma-shaped).

Q17. Match the following and choose the correct combination from the options given Column I (Group Protista) Column II (Example) (a)Chrysophytes (i)Paramecium (b)Dinoflagellates (ii)Euglena (c)Euglenoids (iii)Gonyaulax (d)Protozoans (iv)Diatoms

• (a)- (i), (b) - (iii), (c) - (ii), (d) - (iv)
• (a)- (i), (b) - (iv), (c) - (iii), (d) - (ii)
• (a)- (iv), (b) - (ii), (c) - (iii), (d) - (i)
• (a)- (iii), (b) - (iv), (c) - (i), (d) - (ii)
• (a)- (iv), (b) - (iii), (c) - (ii), (d) - (i)

Solution

Column I (Group Protista) Column II (Example - Answers) (a)Chrysophytes (i) Diatoms (b)Dinoflagellates (ii) Gonyaulax (c)Euglenoids (iii) Euglena (d)Protozoans (iv) Paramecium

Q18. The accumulated food reserve in fungi is

• Protein
• Starch
• Glycogen
• Fat

Solution

Fungi are saprophytes, i.e. they absorb soluble organic substances from dead and decaying matter. In fungi, the food is stored in the form of glycogen and oil droplets.

Q19. Study of fungi is

• Palynology
• Mycology
• Phycology
• Microbiology

Solution

Mycology is the branch of biology which deals with the study of fungi, including their properties, taxonomy and whether they are useful or harmful.

Q20. The beautiful diatoms and desmids are placed under

• Chrysophytes
• Dinoflagellates
• Euglenoids
• Slime moulds

Solution

Diatoms and desmids are placed under Chrysophytes (Kingdom: Protista).

Q21. The influenza virus has 

• DNA
• RNA
• Both RNA and DNA
• Only proteins and no nucleic acids

Solution

Influenza virus is single stranded RNA virus, which cannot serve directly as mRNA but rather as templates for mRNA synthesis via viral transcriptase. 

Q22. Which of the following are intracellular obligate parasites?

• Bacteria
• Viruses
• Slime moulds
• Blue-green algae

Solution

An obligate parasite cannot complete its life cycle without a suitable host. Viruses infect a cell, take the machinery of the cell and replicate. Hence, they are intracellular obligatory parasites.

Q23. Heterotrophic fungi can live as

• Saprophytes
• Symbionts
• Parasites
• All of these

Solution

Saprotrophic fungi absorb organic matter from dead and decaying plants or animals. Some fungi such as rusts and smuts grow as parasites on certain crops such as wheat and corn by decomposing their cellulose. In lichens, the mycobiont part, i.e. fungi are in symbiotic association with the phycobiont part, i.e. algae.

Q24. Virus envelop is known as

• Core
• Capsid
• Virion
• Nucleoprotein

Solution

Virus envelop is made of protein and is called a capsid. It is made of subunits called capsomeres.

Q25. Rhizopus belongs to

• Zygomycetes
• Basidiomycetes
• Ascomycetes
• Deuteromycetes

Solution

Rhizopus belongs to zygomycetes of kingdom Fungi. Fungi which belong to the group zygomycetes show the presence of septate mycelium, sporangia at the tips of hyphae, sexual reproduction by conjugation and absence of non-motile zoospores.

Q26. One of these is not a characteristic feature of cyanobacteria.

• They are multicellular.
• They form colonies.
• They form blooms in polluted water.
• They can fix atmospheric nitrogen.

Solution

Cyanobacteria are unicellular, colonial or filamentous organisms. They are also called blue-green algae.

Q27. Nuclear membrane is absent in

• Monera
• Protista
• Fungi
• Plantae

Solution

Monerans are prokaryotic organisms. Prokaryotic cells do not have membrane-bound organelles and a distinct nucleus bound by the nuclear membrane.

Q28. Tobacco mosaic virus (TMV) genes are 

• Double-stranded RNA
• Single-stranded RNA
• Polyribonucleotides
• Proteinaceous

Solution

Tobacco mosaic virus (TMV) is an elongated and rod-like plant virus with 95% protein and 5% RNA. The genetic material of TMV is linear, single-stranded and 6500 nucleotides in length. 

Q29. Viruses are non-cellular organisms but replicate themselves when they infect the host cell. To which of the following kingdoms do viruses belong?

• Monera
• Protista
• Fungi
• None of these

Solution

Viruses do not belong to any kingdom in biological classification. Viruses are inert when outside the living cell. They are active and can replicate only when they infect the host cell.

Q30. An edible fungus is

• Aspergillus
• Ustilago
• Polyporus
• Morchella

Solution

Species of fungi from the genus Morchella are edible. They belong to the group ascomycetes. Their ascocarps are cap-like, fleshy, sponge-like and edible. They are considered a table delicacy in India and are grown in Kashmir and Punjab. Examples: Morchella esculenta, Morchella deliciosa, Morchella crassipes

Q31. Mycobiont and phycobiont are found in

• Mycorrhiza
• Root
• Lichens
• BGA

Solution

Lichens are a symbiotic association between fungi and algae. The fungal component is heterotrophic and known as mycobiont, while the algal component is autotrophic and known as phycobiont.  

Q32. Who proposed the five kingdom classification?

• Carl Linnaeus
• R. H. Whittaker
• Schwann and Schleiden
• Virchow

Solution

R. H. Whittaker, an American ecologist, proposed the five kingdom classification. He divided organisms into five kingdoms—Monera, Protista, Fungi, Animalia and Plantae.

Q33. Lichens are described as indicators of

• Air pollution
• Water pollution
• Soil pollution
• Agricultural productivity

Solution

Lichens do not grow in polluted air. Hence, the regions where there is minimal growth of lichens despite the suitable condition for their growth may indicate increased pollution in that region.

Q34. The chemical compounds produced by the host plants to protect themselves against fungal infection is

• phytotoxin
• pathogen
• phytoalexins
• hormone

Solution

Phytoalexins are chemical substances produced by plants in response to fungal infection and are toxic to fungi.

Q35. Thread-like filaments which constitute the body of fungi are

• Paraphyses
• Rhizoids
• Haptera
• Hyphae

Solution

Hyphae are long, thread-like and filamentous. The network of hyphae is known as mycelium.

Q36. Bacteria that live in hot springs are called

• Methanogens
• Halophiles
• Thermoacidophiles
• Thermohalophiles

Solution

Thermoacidophiles are bacteria which can thrive at very high temperatures and in extreme acidic environments.

Q37. Mycorrhizae show

• Ammensalism
• Parasitism
• Commensalism
• Symbiosis

Solution

Mycorrhiza is the symbiotic association of fungus with the roots of higher plants. The fungus receives food and shelter from the tree. In return, the fungus absorbs water and minerals from the soil and transports it to the tree, thus helping the tree to grow.

Q38. Among rust, smut and mushroom, all the three

• Are pathogens.
• Are saprobes.
• Bear ascocarps.
• Bear basidiocarps.

Solution

Rust, smut and mushroom belong to phylum basidiomycetes of kingdom Fungi. Basidiomycetes decompose the woody structure of trees. They decompose cellulose and lignin. Rusts are parasitic on certain species of wheat and coffee. Smuts infect corn, wheat etc., and mushrooms are parasitic on the bark and roots of certain trees.

Q39. Common bread mould is

• Yeast
• Rhizopus
• Clostridium
• Myxovirus

Solution

Rhizopus is a saprophytic fungus. It spoils food items such as bread, strawberries, apples etc. It is frequently observed growing on bread and is hence also called common bread mould.

Q40. In plants, mosaic formation, leaf rolling and curling, yellowing of plant parts, vein clearing, dwarfing and stunted growth are symptoms of 

• Bacterial diseases
• Mycoplasmal diseases
• Viral diseases
• Fungal diseases