Correct Answer: (d)
E. coli is a harmless commensal in the human colon (not to be confused with E. histolytica).
Q2. Which of the following secretes toxins during storage conditions of crop plants?
Correct Answer: (a)
Aspergillus flavus produces Aflatoxins during storage.
Q3. Mycorrhiza represents
Correct Answer: (c)
Mutualism between fungi and roots of higher plants.
Q4. Which one of the following statements about mycoplasma is wrong?
Correct Answer: (b)
Penicillin acts on cell wall synthesis; Mycoplasma lacks a cell wall, so it's resistant.
Q5. Which of the following are most suitable indicators of SO2 pollution in the environment?
Correct Answer: (d)
Lichens vanish first in areas with high air pollution.
Q6. In the light of recent classification of living organisms into three domains of life (bacteria, archaea and eukarya), which one of the following statements is true about archaea?
Correct Answer: (b)
Archaea have unique cell membrane lipids and cell wall compositions.
Q7. Tobacco Mosaic Virus (TMV) genes are
Correct Answer: (b)
TMV genetic material is a single strand of RNA.
Q8. Plant decomposers are
Correct Answer: (a)
Bacteria (Monera) and Fungi are the primary natural decomposers.
Q9. Protista includes
Correct Answer: (d)
Protista includes various metabolic groups.
Q10. Which statement is correct for bacterial transduction?
Correct Answer: (a)
Transduction is virus-mediated gene transfer.
Q11. Mad cow disease in cattle is caused by an organism which has:
Correct Answer: (c)
Prions (BSE) are abnormally folded infectious proteins.
Q12. Which one of the following is true for fungi?
Correct Answer: (c)
Fungi are absorptive heterotrophs.
Q13. Lichens indicate SO2 pollution because they
Correct Answer: (c)
They are 'Canaries in the coal mine' for air quality.
Q14. Organisms called methanogens are most abundant in a:
Correct Answer: (b)
Methanogens live in the rumen of cattle and are abundant in dung.
Q15. Auxopores and hormocysts are formed, respectively, by:
Correct Answer: (a)
Auxospores are in diatoms; Hormocysts are in some BGA.
Q16. Viruses have either DNA or RNA as the genetic material. Viruses having RNA as the genetic material are known as retroviruses.
Correct Answer: (a)
Retroviruses (like HIV) use RNA as their genetic blueprint.
Q17. In prokaryotes, the genetic material is
Correct Answer: (d)
Prokaryotic DNA is circular and lacks basic histone proteins.
Q18. Choose the wrong statements:
Correct Answer: (b)
Morels and Truffles are highly prized edible delicacies.
Q19. Which one of the following fungi contains hallucinogens?
Q20. In the five-kingdom system of classification, which single kingdom out of the following can include blue green algae, nitrogen-fixing bacteria and methanogenic archaebacteria?
Correct Answer: (d)
All prokaryotic organisms belong to the kingdom Monera.
Q21. Tobacco mosaic virus is a tubular filament of size
Correct Answer: (d)
Dimensions are roughly 300nm length and 18-20nm diameter.
Q22. Mycorrhiza is
Correct Answer: (a)
Fungus-root mutualism.
Q23. Adhesive pad of fungi penetrates the host with the help of
Correct Answer: (a)
Appressorium uses both physical force and hydrolytic enzymes to penetrate.
Q24. The most thoroughly studied fact of the known bacteria-plant interactions is the
Correct Answer: (c)
Ciliates (like Paramecium) have nuclear dimorphism.
Q26. Virus is an ultra microscopic nucleoprotein entity which becomes active only inside a living cell. It resembles living beings due to presence of genetic material and reproduction.
Correct Answer: (a)
Reproduction and heredity are living traits of viruses.
Q27. Which of the following statements is incorrect?
Correct Answer: (d)
Yeasts are unicellular and do not form mycelial hyphae.
Q28. The causative agent of mad-cow disease is a
Correct Answer: (a)
Prions cause spongiform encephalopathies like BSE.
Q29. Which of the following structures is not found in a prokaryotic cell?
Correct Answer: (d)
Prokaryotes lack a membrane-bound nucleus.
Q30. Which one belongs to monera?
Correct Answer: (b)
Escherichia (bacterium) is a member of Monera.
Q31. Rickettsiae constitute a group under
Correct Answer: (a)
Rickettsiae are specialized obligate intracellular bacteria.
Q32. Which fungal disease spreads by seed and flowers?
Correct Answer: (a)
Loose smut (Ustilago) is internally seed-borne and infects ovaries through flowers.
Q33. The vector for sleeping sickness is
Correct Answer: (b)
Glossina (Tse-tse fly) is the vector.
Q34. Single-celled eukaryotes are included in:
Correct Answer: (a)
Protista is the kingdom for single-celled eukaryotes.
Q35. The structures that help some bacteria to attach to rocks and/or host tissues are:
Correct Answer: (a)
Fimbriae are bristle-like fibers used for attachment.
Q36. True nucleus is absent in:
Correct Answer: (d)
Anabaena is a prokaryotic cyanobacterium.
Q37. Which one single organism or the pair of organisms is correctly assigned to its taxonomic group?
Correct Answer: (c)
Yeast (Saccharomyces) is a unicellular ascomycete fungus.
Q38. One scientist cultured Cladophora in a suspension of Azotobacter and illuminated the culture by splitting light through a prism. He observed that bacteria accumulated mainly in the region of:
Correct Answer: (a)
Photosynthesis (O2 production) is highest in blue and red light regions.
Q39. How many organisms in the list given below are autotrophs? Lactobacillus, Nostoc, Chara, Nitrosomonas, Nitrobacter, Streptomyces, Saccharomyces, Trypanosoma, Porphyra, Wolffia
Correct Answer: (c)
Nostoc, Chara, Nitrosomonas, Nitrobacter, Porphyra, Wolffia are autotrophs. Total = 6.
Q40. Albugo candida is an obligate parasite causing white rust on members of family
Correct Answer: (a)
Causes white rust of crucifers (Mustard family).
Q41. Which among the following is not a prokaryote?
Correct Answer: (a)
Saccharomyces (Yeast) is a eukaryotic fungus.
Q42. Satellite RNAs are present in some
Correct Answer: (a)
Satellite RNAs require a helper virus (common in plants) to replicate.
Q43. In which of the animals dimorphic nucleus is found?
Correct Answer: (d)
Paramecium has a large macronucleus and a small micronucleus.
Q44. The motile bacteria are able to move by:
Correct Answer: (b)
Flagella are the primary organelles for bacterial locomotion.
Q45. What is true for archaebacteria?
Correct Answer: (d)
Archaebacteria are considered 'living fossils' and the oldest life forms.
Q46. African sleeping sickness is due to
Correct Answer: (c)
Caused by T. gambiense and spread by Glossina (Tse-tse fly).
Q47. Which of the following organisms are known as chief producers in the oceans?
Correct Answer: (b)
Diatoms are the 'pearls of the ocean' and primary producers.
Q48. Which among the following are the smallest living cells, known without a definite cell wall, pathogenic to plants as well as animals and can survive without oxygen?
Correct Answer: (b)
Mycoplasmas are the smallest known prokaryotes lacking a cell wall.
Q49. Black rust of wheat is caused by
Correct Answer: (a)
Puccinia graminis tritici causes black rust.
Q50. Thermococcus, Methanococcus and Methanobacterium exemplify:
Correct Answer: (a)
Some Archaea possess proteins homologous to eukaryotic histones.
Q51. Cauliflower mosaic virus contains
Correct Answer: (c)
CaMV is a rare plant virus containing double-stranded DNA.
Q52. Nitrogen fixer soil organisms belong to
Correct Answer: (b)
Bacteria (Rhizobium, Azotobacter, BGA) are the primary biological N2 fixers.
Q53. The hereditary material present in the bacterium Escherichia coli is
Correct Answer: (c)
E. coli has a double-stranded circular DNA molecule.
Q54. Name the organisms which do not derive energy directly or indirectly from sun
Correct Answer: (a)
Chemoautotrophs get energy from chemical oxidation of inorganic compounds.
Q55. Transfer of genetic information from one bacterium to another in the transduction process is through
Correct Answer: (b)
Transduction uses viruses (bacteriophages) as vectors.
Q56. The chief advantage of encystment to an Amoeba is
Correct Answer: (b)
Cyst formation protects Amoeba during unfavorable conditions.
Q57. A few organisms are known to grow and multiply at temperatures of 100–105°C. They belong to
Correct Answer: (b)
Thermoacidophiles grow in extreme heat and acidic conditions.
Q58. In which group of organisms the cell walls form two thin overlapping shells which fit together?
Correct Answer: (d)
Diatoms (Chrysophytes) have soap-box like silica walls.
Q59. Which of the following statements is correct?
Correct Answer: (b)
Lichens are extremely sensitive to SO2 and do not thrive in polluted environments.
Q60. Which is true about Trypanosoma?
Correct Answer: (a)
Trypanosoma exists in different structural forms during its life cycle.
Q61. Five kingdom system of classification suggested by R.H. Whittaker is not based on:
Correct Answer: (a)
Whittaker's system was based on cell structure, body organization, nutrition, reproduction, and phylogenetic relationships.
Q62. The cyanobacteria are also referred to as
Correct Answer: (d)
Cyanobacteria are commonly known as Blue-Green Algae (BGA).
Q63. Excretion in Amoeba occurs through
Correct Answer: (d)
Though major waste diffuses, some is excreted via CV.
Q64. What is common about Trypanosoma, Noctiluca, Monocystis and Giardia?
Correct Answer: (d)
All are members of the kingdom Protista (unicellular eukaryotes).
Q65. Which one is the wrong pairing for the disease and its causal organism?
Correct Answer: (d)
Late blight of potato is caused by Phytophthora infestans.
Q66. Macro and micronucleus are the characteristic feature of
Correct Answer: (a)
Ciliates have dimorphic nuclei.
Q67. Which of the following statements is wrong for viroids?
Correct Answer: (d)
Viroid RNA is of very LOW molecular weight.
Q68. Which one of the following statements about viruses is correct?
Correct Answer: (d)
Viruses must live inside host cells to survive and replicate.
Q69. Which of the following environmental conditions are essential for optimum growth of Mucor on a piece of bread? A. Temperature of about 25°C B. Temperature of about 5° C C. Relative humidity of about 5% D. Relative humidity of about 95% E. A shady place F. A brightly illuminated place
Correct Answer: (a)
Mucor is a fungus. Fungi generally grow best in warm (around 25°C), humid (95% humidity), and shady/dark places.
Q70. Artificial system of classification was first used by
Correct Answer: (a)
Linnaeus used an artificial system (sexual system) based on stamen characteristics.
Q71. Viroids differ from viruses in having;
Correct Answer: (c)
Viroids are exclusively composed of naked ssRNA.
Q72. Specialized cells for fixing atmospheric nitrogen in Nostoc are
Correct Answer: (b)
Heterocysts are thick-walled specialized cells for N2 fixation.
Q73. Most of the Lichens consist of
Correct Answer: (b)
Typically Green algae or Cyanobacteria paired with Ascomycetes.
Q74. A bite of Tse-Tse fly may pass to humans
Correct Answer: (b)
Tse-tse flies transmit T. gambiense.
Correct Answer: (a)
BGA perform oxygenic photosynthesis and fix nitrogen via nitrogenase.
Q80. Sex factor in bacteria is
Correct Answer: (b)
The Fertility (F) plasmid acts as the sex factor.
Q81. Membrane-bound organelles are absent in:
Correct Answer: (b)
Streptococcus is a bacterium (prokaryote).
Q82. Which of the following shows coiled RNA strand and capsomeres?
Correct Answer: (b)
TMV has a helical symmetry with coiled RNA inside capsomeres.
Q83. Which pair of the following belongs to Basidiomycetes?
Correct Answer: (d)
Puffballs and Bird's nest fungi belong to Basidiomycota.
Q84. Puccinia forms
Correct Answer: (b)
Uredospores and Teleutospores are formed on the primary host (Wheat).
Q85. Pick up the wrong statement
Correct Answer: (c)
Monera (bacteria) are prokaryotic and lack a nuclear membrane.
Q86. Which statement is wrong for viruses?
Correct Answer: (b)
Viruses have various symmetries (polyhedral, helical, binal).
Q87. System of classification used by Linnaeus was
Correct Answer: (b)
Linnaeus' system was artificial as it relied on a few superficial traits.
Q88. In fungi stored food material is
Correct Answer: (a)
Fungi store excess energy as Glycogen and oil droplets.
Q89. Temperature tolerance of thermal blue-green algae is due to
Correct Answer: (d)
Thermal resistance is due to the presence of stable homopolar bonds in proteins.
Q90. Viruses are no more 'alive' than isolated chromosomes because
Correct Answer: (a)
Neither can reproduce or show metabolism outside a host cell.
Q91. Phylogenetic classification is based on
Correct Answer: (d)
Phylogenetic classification is based on evolutionary relationships (phylogeny).
Q92. Protistan genome has
Correct Answer: (a)
Protists are eukaryotes; they have membrane-bound nuclei.
Q93. The fungus that causes the disease 'Ergot of Rye' is Claviceps purpurea. It contains many poisonous alkaloids. The hallucinogenic drug LSD is extracted from this fungi. Rust of wheat is used by
Correct Answer: (a)
Rust refers to Puccinia.
Q94. Genetic information in Paramecium is contained in
Correct Answer: (a)
The micronucleus is responsible for genetic/sexual functions.
Q95. The imperfect fungi which are decomposers of litter and help in mineral cycling belong to:
Correct Answer: (d)
Deuteromycetes (Imperfect Fungi) are major litter decomposers.
Q96. Which of the following components provides sticky character to the bacterial cell?
Correct Answer: (c)
Glycocalyx (capsule/slime layer) provides adhesion and protection.
Q97. Escherichia coli is used extensively in biological research as it is
Correct Answer: (a)
E. coli is the model organism for molecular biology because it's cheap and grows fast.
Q98. Which one of the following organisms is not an example of eukaryotic cells?
Correct Answer: (b)
E. coli is a prokaryotic bacterium.
Q99. In the five-kingdom classification, Chlamydomonas and Chlorella have been included in
Correct Answer: (a)
Whittaker placed them in Protista due to their unicellular eukaryotic nature.
Q100. Bacteria lack alternation of generation because there is
Correct Answer: (a)
Bacteria reproduce asexually; they lack true sexual fusion and meiosis.
Q101. The infective stage of malarial parasite Plasmodium that enters human body is
Correct Answer: (b)
Sporozoites injected by the mosquito infect the human liver.
Q102. The chemical compounds produced by the host plants to protect themselves against fungal infection is
Correct Answer: (c)
Phytoalexins are antimicrobial compounds synthesized by plants in response to stress.
Q103. Photosynthetic bacteria have pigments in
Correct Answer: (d)
Prokaryotes lack plastids; pigments are in internal membrane folds called chromatophores.
Q104. The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the ones categorised as:
Correct Answer: (d)
Lactobacillus (curd) and Streptomyces (antibiotics) are heterotrophs.
Q105. Fungi are nutritionally saprophytes, which grow on dead and decaying matter. They secrete enzyme to the external medium where digestion takes place and digested food is absorbed by the body surface. They convert complex organic constituents of dead body into simple soluble forms. That is why fungi are regarded as decomposers.
Correct Answer: (a)
Fungi and bacteria are the primary decomposers.
Q106. Classification given by Bentham and Hooker is
Correct Answer: (b)
They provided a comprehensive natural system for flowering plants.
Q107. Which of the following is correct about viroids?
Correct Answer: (a)
Viroids are naked RNA particles discovered by T.O. Diener.
Q108. There exists a close association between the alga and the fungus within a lichen. The fungus
Correct Answer: (a)
Symbiosis: Fungi provide shelter and water; Algae provide food.
Q109. Protists obtain food as
Correct Answer: (a)
Protists show diverse nutritional modes.
Q110. In eubacteria, a cellular component that resembles eukaryotic cells is:
Correct Answer: (a)
The basic structure of the plasma membrane (lipid bilayer) is conserved.
Q111. One of the major components of cell wall of most fungi is
Correct Answer: (a)
Fungal cell wall is made of Chitin (N-acetylglucosamine polymer).
Q112. Which of the following are found in extreme saline conditions?
Correct Answer: (d)
Halophiles (Archaebacteria) live in high salt conditions.
Q113. Which one of the following matches is correct?
Correct Answer: (a)
Alternaria belongs to Fungi Imperfecti (Deuteromycetes).
Q114. Which of the following are likely to be present in deep sea water?
Correct Answer: (d)
Archaebacteria (like methanogens/thermoacidophiles) thrive in extreme conditions.
Q115. Virus envelope is known as:
Correct Answer: (a)
The protective protein coat is called a capsid.
Q116. The main difference in Gram (+)ve and Gram (–)ve bacteria resides in their
Correct Answer: (a)
Difference lies in the peptidoglycan thickness and lipid content of the cell wall.
Q117. In Amoeba and Paramecium osmoregulation occurs through
Correct Answer: (c)
Contractile vacuoles pump out excess water.
Q118. The function of contractile vacuole, in protozoa, is
Correct Answer: (c)
It maintains water balance in the cell.
Q119. Plasmodium, the malarial parasite, belongs to class
Correct Answer: (c)
Plasmodium belongs to Sporozoa (lack locomotor organelles).
Q120. Smut disease is caused by Ustilago species of basidiomycetes fungi. It is characterised by
Correct Answer: (a)
Ustilago species produce massive black spore masses.
Q121. Viruses that infect bacteria, multiply and cause their lysis, are called
Correct Answer: (c)
Lytic phages cause immediate burst/death of the bacterial cell.
Q122. Which of the following statements is incorrect?
Correct Answer: (c)
The genetic material (DNA/RNA) is the infective part, not the capsid.
Q123. Organisms which are indicator of SO2 pollution of air
Correct Answer: (b)
Lichens are the best bio-indicators for SO2.
Q124. Lichens are a well known combination of an alga and a fungus where fungus has
Correct Answer: (d)
Mutualism (Symbiosis).
Q125. The causal organism for African sleeping sickness is
Correct Answer: (d)
Trypanosoma gambiense is the main causal agent.
Q126. Which one of the following is a slime mould?
Correct Answer: (a)
Physarum polycephalum is a cellular/acellular slime mould.
Q127. Trypanosoma belongs to class
Correct Answer: (b)
It moves using a flagellum.
Q128. Which one of the following is not true about lichens?
Correct Answer: (d)
Lichens grow extremely slowly (often < 1mm to 1cm per year).
Q129. Bacterial leaf blight of rice is caused by a species of