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Topicwise Solved Previous Year Qs 10
Biological Classification
1. The causal organism for African
sleeping sickness is [1989] (a) Trypanosoma cruzi
(b) T. rhodesiense (c) T. tangela
(d) T. gambiense Solution: (d) African sleeping sickness disease also called trypanosomiasis common in Africa is
caused by parasite Trypanosoma
gambiense. The parasite is transmitted by Tse-Tse fly (Glossina palpalis).
2. The vector for sleeping sickness is
[1989] (a) House fly
(b) Tse-Tse fly (c) Sand fly
(d) Fruit fly
Solution: (b) Vector for sleeping sickness is TseTse fly
(Glossina palpalis). The parasite Trypanosoma is transmitted through the
bite of this fly. Tse-tse have been extensively studied because they are
biological vectors of the African
trypanosomiasis, deadly disease which include sleeping sickness in people and
nagana in cattle. Tse-tse have existed in the modern morphological form for at least
34 million years since fossil tse-tse have been recovered from the Florissant Fossil
Beds in Colorado.
3. Trypanosoma belongs to class [1989]
(a) Sarcodina (b) Zooflagellata
(c) Ciliata (d) Sporozoa
Solution: (b) Zooflagellata of Protozoan Protista. They
have flagella and heterotrophic (Parasitic) mode of nutrition.
4. Malaria fever coincides with liberation of
(a) cryptomerozoites (b) metacryptomerozoites
(c) merozoites (d) trophozoites
Solution: (c)
Malarial parasite, (Plasmodium vivax),
Protist of class Sporozoa, digenetic parasite causes malarial fever in human. The
malarial parasite was discovered by Laveran (1880). Sir Ronald Ross (1898)
discovered that Malaria disease is spread by mosquitoes. Its life cycle completes in
two organisms-Primary host, female Anopheles mosquito and man (Intermediate
or Secondary host). It enters into human
blood-through sporozoites. Malarial fever begins with the release of merozoites in the
liver cells, from RBC of human.
5. A bite of Tse-Tse fly may pass to humans
(a) Leishmania donovani
(b) Trypanosoma gambiense (c) Entamoeba histolytica
(d) Plasmodium vivax Solution: (b)
Tse-Tse fly is vector of sleeping sickness disease and it transmits Trypanosoma
gambiense through its bite.
6. The infective stage of malarial
parasite Plasmodium that enters human body is [1989]
(a) merozoite (b) sporozoite
(c) trophozoite (d) minuta form
Solution: (b) The infective stage of Plasmodium that
enters human blood is sporozoite.
7. Lichens indicate SO2 pollution
because they [1989] (a) show association between algae and
fungi (b) grow faster than others
(c) are sensitive to SO2
(d) flourish in SO2 rich environment Solution: (c)
Lichens typically grow in harsh environments in nature, most lichens,
especially epiphytic fruticose species and those containing cyanobacteria, are
sensitive to manufactured pollutants. Hence, they have been widely used as
pollution indicator organisms. Lichens are
symbiotic associations of a fungus with a photosynthetic partner (called a photobiont
Topicwise Solved Previous Year Qs 11
or phycobiont) that can produce food for
the lichen from sunlight.
8. Which one belongs to monera? [1990] (a) Amoeba
(b) Escherichia (c) Gelidium
(d) Spirogyra Solution: (b) Whittaker (1969) divided organisms into
five kingdoms: Monera, Protista, Plantae, Fungi and Animalia. Kingdom Monera
includes all prokaryotes – Mycoplasma, bacteria, actinomycetes, blue-green algae,
archaebacteria, methanogens. Escherichia is bacteria, Amoeba, Gelidium come under
Protista, Spirogyra is algae.
9. The main difference in Gram (+)ve and
Gram (–)ve bacteria resides in their [1990, 2001]
(a) cell wall (b) cell membrane
(c) cytoplasm (d) flagella
Solution: (a) Gram +(ve) and Gram –(ve) bacteria separates on the basis of their cell wall
composition. Christian Gram on the basis of staining behaviour of the cell wall with
Gram‘s stain, grouped bacteria into Gram +ve and Gram –ve type. The bacteria which
retain blue or purple colour after staining are Gram +ve e.g. Bacillus subtilis and
which loses blue colour is Gram –ve e.g. E.
coli. In Gram –ve stain is washed due to high lipid content in the cell wall having
thick wall, Gram +ve has single layered cell wall
10. Genetic information in Paramecium
is contained in [1990]
(a) micronucleus (b) macronucleus
(c) both micronucleus and macronucleus (d) mitochondria
Solution: (a)
11. Which is true about Trypanosoma? [1990]
(a) Polymorphic (b) Monogenetic
(c) Facultative Parasite (d) Non-pathogenic
Solution: (a) Trypanosoma is polymorphic i.e. it exists
in different forms in the successive stages
of its life cycle. These are Leishmania, Leptomonad, Crituidial and trypanosomal
stages.
12. Amoebiasis is prevented by [1990] (a) eating balanced food
(b) eating plenty of fruits
(c) drinking boiled water (d) using mosquito nets
Solution: (c) Amoebiasis or amoebic dysentry is caused
by a parasite Entamoeba histolytica present in the upper part of large intestine
of human. It is caused due to ingesting contaminated food or water with cyst
(trophozoite) of Entamoeba. It feeds on
R.B.C of intestinal blood capillaries and damages intestinal mucosa secreting an
enzyme - histolysin.
13. Plasmodium, the malarial parasite, belongs to class [1990]
(a) Sarcodina (b) Ciliata
(c) Sporozoa
(d) Dinophyceae Solution: (c) Plasmodium belongs to class Sporozoa of protozoan profists. It is an endoparasite
lacking any locomotony structure and contractile vacules. It reproduces through
spore formation.
14. A nonphotosynthetic aerobic
nitrogen fixing soil bacterium is [1990, 1994]
(a) Rhizobium (b) Clostridium
(c) Azotobacter (d) Klebsiella
Solution: (c) Azotobacter is free living soil bacteria that are able to pick up dinitrogen from the soil
and fixes it into organic nitrogenous
Topicwise Solved Previous Year Qs 12
material like aminoacid. Clostridium is
anaerobic free living soil N2 fixing bacteria. Rhizobium is symbiotic N2 fixing bacteria.
15. Absorptive heterotrophic nutrition is
exhibited by [1990] (a) Algae
(b) Fungi (c) Bryophytes
(d) Pteridophytes
Solution: (b) 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 absorbed by the body surface. They
convert complex organic constituents of
dead body into simple soluble forms. That is why Fungi are decomposers.
16. Who discovered Plasmodium in
R.B.C of human beings? [1991] (a) Ronald Ross
(b) Mendel (c) Laveran
(d) Stephens
Solution: (c) Laveran discovered Plasmodium in R.B.C
of human beings and concluded that malaria is caused by Plasmodium vivax. Sir
Ronal Ross (1896) was the first to observe oocytes of Plamodium in female Anopheles.
17. Malignant tertian malarial parasite is
[1991]
(a) Plasmodium falciparum (b) P. vivax
(c) P. ovale (d) P. malariae
Solution: (a) In human beings different types of malaria
are caused by 4 different species of
Plasmodium. They are: 1. Benign Tertian Malaria – Plasmodium vivax.
2. Malignant (Pernicious or cerebral) Tertian Malaria – Plasmodium falciparum.
3. Quartan Malaria – Plasmodium malariae.
4. Mild Tertian Malaria – Plasmodium ovale.
18. Name the organisms which do not derive energy directly or indirectly from
sun [1991]
(a) Chemosynthetic bacteria
(b) Pathogenic bacteria (c) Symbiotic bacteria
(d) Mould Solution: (a) Chemosynthetic bacteria does not require sunlight as a source of energy directly or
indirectly. The energy for the synthesis of food is obtained by the oxidation of certain
inorganic substances present in the
medium. The chemical energy obtained from oxidation reaction is trapped in ATP
molecules. The ATP is used in CO2 assimilation.
19. African sleeping sickness is due to
[1991]
(a) Plasmodium vivax transmitted by Tse tse fly
(b) Trypanosoma lewsii transmitted by Bed Bug
(c) Trypanosoma gambiense transmitted by Glossina palpalis
(d) Entamoeba gingivalis spread by Housefly.
Solution: (c) I. African sleeping sickness disease also called as trypansomiasis common in
western and central parts of African continent. II. The disease is caused by
parasite Trypanosoma gambiense of class zooflagellata. III. The parasite is
transmitted (vector) through bite of Tse-Tse fly (Glossina palpalis). IV. The disease
appears when the causal organism enters
into cerebrospinal fluid of human. V. Trypanosoma is an obligate parasite,
Digenetic and Polymorphic organism.
20. In Amoeba and Paramecium osmoregulation occurs through [1991,
2002]
(a) pseudopodia (b) nucleus
(c) contractile vacuole (d) general surface
Solution: (c) Contractile vacuole in Amoeba and
Paramecium maintain the water balance of the cell. This is known as osmoregulation.
21. Bacteria lack alternation of generation because there is [1991, 1992]
(a) neither syngamy nor reduction division
Topicwise Solved Previous Year Qs 13
(b) distinct chromosomes are absent
(c) no conjugation (d) no exchange of genetic material
Solution: (a) In bacteria asexual reproduction through
binary fission is the most common method of multiplication. Sexual reproduction
which comprises of syngamy and meiosis is entirely absent. Hence no gamete formation
takes place. In sexually reproducing
organism alternation of generation occurs.
22. The part of life cycle of malarial parasite Plasmodium vivax, that is
passed in female Anopheles is [1992] (a) sexual cycle
(b) pre-erythrocytic schizogony
(c) exoerythrocytic schizogony (d) post-erythrocytic schizogony
Solution: (a) Plasmodium vivax completes Sexual cycle
or Gamogony in female Anopheles mosquito. Asexual cycle is passed in man
(Schizogony).
23. Organisms which are indicator of
SO2 pollution of air [1992] (a) Mosses
(b) Lichens (c) Mushrooms
(d) Puffballs Solution: (b) Lichens are composite organisms representing a symbiotic association
between fungus and a algae. It can be
Crustose, Foliose and Fruticose types. They are the pioneer organisms in a new habitat.
Lichens used as indicator of air pollution. It does grow in the environment where
pollution level is high, SO2 is strong air pollutant and lichens are very sensitive to
SO2.
24. Escherichia coli is used extensively
in biological research as it is [1993] (a) easily cultured
(b) easily available (c) easy to handle
(d) easily multiplied in host Solution: (a) Escherichia coli, lives as a symbiont in
human intestine.
25. Genophore/bacterial genome or
nucleoid is made of [1993] (a) histones and nonhistones
(b) RNA and histones (c) a single double stranded DNA
(d) a single stranded DNA Solution: (c) The bacterial genome/nucleoid is made of single circular double stranded DNA
without histone protein as it is a
prokaryotic organisms. The genome contains some 100 chemical sites or loci.
Each locus contains many genes. E coli contains about 4000 genes.
26. If all ponds and puddles are
destroyed, the organism likely to be
destroyed is [1993] (a) Leishmania
(b) Trypanosoma (c) Ascaris
(d) Plasmodium Solution: (d) Plasmodium transmitted through female Anopheles mosquito to Human and the
most favourite dwelling place for Anopheles
is water or moist places like ponds and puddles.
27. Schizogont stage of Plasmodium
occurs in human cells [1993] (a) Erthrocytes
(b) Liver cells (c) Erythrocytes and liver cells
(d) Erythrocytes, liver cells and spleen cells
Solution: (c) Schizogont or Asexual stage occurs in
human erythrocytes and liver cells.
28. Reverse transcriptase is [1994] (a) RNA dependent RNA polymerase
(b) DNA dependent RNA polymerase
(c) DNA dependent DNA polymerase (d) RNA dependent DNA polymerase
Solution: (d) H. Temin and D. Baltimore (1970)
discovered that tumor viruses contain RNA as genetic material and replicate by
synthesizing complementary DNA. This process is called reverse transcription and
it is carried by an RNA dependent DNA
polymerase called as reverse transcriptase.
Topicwise Solved Previous Year Qs 14
29. Tobacco Mosaic Virus (TMV) genes
are [1994] (a) double stranded RNA
(b) single stranded RNA (c) polyribonucleotides
(d) proteinaceous Solution: (b) All viruses are nucleoprotein (Nucleic acid + Protein) in the structure. The nucleic acid
(DNA and RNA) is genetic material. In a
particular virus either DNA or RNA is genetic material never both are present in a
virus. Hence viruses are: (i) Double stranded DNA or ds DNA - Hepatitis B (ii)
Single stranded DNA or ss DNA - coliphage (iii) Double stranded RNA or ds RNA - Reo
virus, wound Tumor virus (iv) Single
stranded RNA or ss RNA - Tobacco mosaic virus (TMV)
30. Organelle/organoid involved in
genetic engineering is [1994] (a) plasmid
(b) mitochondrion (c) golgi apparatus
(d) lomasome
Solution: (a) Besides Nuclear DNA, bacteria possesses
extranuclear DNA (outside the nucleoid region) called as plasmid which can
replicate independently. Due to this property plasmid holds great importance in
genetic engineering. Plasmid can be taken out of bacteria and made to combine with
desired DNA segment. A plasmid carrying
DNA of other organism now it is known as cosmid which can be introduced into any
desired cells. This is the basis of genetic engineering.
31. The term antibiotic was first used by
[1994, 2003]
(a) Flemming (b) Pasteur
(c) Waksman (d) Lister
Solution: (c) The term antibiotics was coined by
Waksman but the first known antibiotic, penicillin was extracted from fungi
Penicillium notatum by A Flemming 1944.
Antibiotics are the chemicals that are produced from the living organisms, used
to kill another living organisms. About
2300 antibiotics discovered so far e.g.
Streptomycin, Tetracycline etc.
32. Temperature tolerance of thermal blue-green algae is due to [1994]
(a) cell wall structure (b) cell organisation
(c) mitochondrial structure (d) homopolar bonds in their proteins
Solution: (d) Some of the blue green algae can tolerate extremes of temperature due to presence of
gelatinous sheath, and compactness of protein molecules in protoplasm.
33. Nonsymbiotic nitrogen fixers are
[1994]
(a) Azotobacter (b) Pseudomonas
(c) soil fungi (d) blue-green algae
Solution: (a) Azotobacter is nonsymbiotic, free living
nitrogen fixing bacteria.
34. Rickettsiae constitute a group under
[1994] (a) bacteria
(b) viruses (c) independent group between bacteria and
viruses (d) fungi
Solution: (c) Rickettsias are tiny obligate, intracellular
parasites found in blood sucking insects
like lices, mites, ticks. They were first observed by Ricketts 1909 but it was
properly described by Rocha-lime 1916, who named them as Rickettsia. They have
mucopeptide cell wall with DNA as genetic material and are independent entity
produces diseases like Q-fever, typhus etc.
35. Nitrogen fixer soil organisms belong
to [1994] (a) mosses
(b) bacteria (c) green Algae
(d) soil Fungi Solution: (b) Only some bacteria and Blue green algae
(cynobacteria) has capacity to fix atmospheric nitrogen. • Bacteria:
Azotobacter, Rhizobium, Frankia etc. •
Topicwise Solved Previous Year Qs 15
Bluegreenalgae: Nostoc, Oscillatoria,
Anabaena etc.
36. Protistan genome has [1994] (a) membrane bound nucleoproteins
embedded in cytoplasm (b) free nucleic acid aggregates
(c) gene containing nucleoproteins condensed together in loose mass
(d) nucleoprotein in direct contact with cell
substance Solution: (a) Protistans are eukaryotes and their genetic material is organised in form of nucleus.
DNA is associated with histone protein.
37. Entamoeba coli causes [1994]
(a) Pyrrhoea (b) Diarrhoea
(c) Dysentery (d) None
Solution: (d) Pyrrhoea is caused by bacterial infections
along with other factor, Diarrhoea by caused by rotavirus along with many other
factor. Dysentery by Entamoeba histolytica.
38. Protists obtain food as [1994]
(a) photosynthesisers, symbionts and holotrophs
(b) photosynthesisers (c) chemosynthesisers
(d) holotrophs Solution: (a) Members of kingdom Protista have diverse
mode of nutrition. They are photosynthetic, saprophytic parasitic and ingestive. They
are major heterotroph.
39. Protista includes [1994] (a) heterotrophs
(b) chemoheterotrophs
(c) chemoautotrophs (d) all the above
Solution: (d) Kingdom Protista includes flagellates
(euglenophyceae), diatoms, dinoflagellates, slime moulds, sarcodines, ciliates,
sporozoans. They are photosynthetic, chemotrophic, heterotropic in mode of
nutrition.
40. Ustilago caused plant diseases called
smut because [1994] (a) they parasitise cereals
(b) mycelium is back (c) they develop sooty masses of spores
(d) affected parts becomes completely black.
Solution: (d) Smut disease caused by Ustilago species of basidiomycetes fungi. It is characterised by
formation of black coloured chlamydospores or teleutospores called
smut spore due to which the affected part becomes black.
41. Claviceps purpurea is causal
organism of
(a) Smut of Barley (b) Rust of Wheat
(c) Ergot of Rye (d) Powdery Mildew of Pea.
Solution: (c) 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 Puccinia graminis. • Powdery Mildew of Pea
is caused by Erysiphae.
42. Decomposers are organisms that [1994]
(a) illaborate chemical substances, causing
death of tissues (b) operate in living body and simplifying
organic substances of cells step by step (c) attack and kill plants as well as animals
(d) operate in relay terms, simplifying step by step the organic constituents of dead
body Solution: (d) Decomposers act on dead bodies
converting complex organic constituents into simple soluble form. They obtain their
energy from dead organisms. Decomposers themselves are organisms (often fungi,
earthworms, or bacteria) that break down
Topicwise Solved Previous Year Qs 16
organic materials to gain nutrients and
energy. Decomposers accelerate the natural process of decomposition. They supply the
required nutrients for other trophic levels. The fungi on the tree are decomposers.
When an organism dies, it leaves behind nutrients that are locked tightly together. A
scavenger might eat the carcass, but its feces would still contain a considerable
amount of unused energy and nutrients.
Decomposers will later induce further breakdown. This last step releases raw
nutrients (such as nitrogen, phosphorus and magnesium) in a form usable to plants,
which quickly incorporate the chemicals into their own cells. This process greatly
increases the nutrientload of an ecosystem,
in turn allowing for greater biodiversity.
43. Mycorrhiza represents [1994, 2003] (a) antagonism
(b) endemism (c) symbiosis
(d) parasitism Solution: (c) Mycorrhiza is symbiotic association
between fungi and roots of higher plants. Mycorrhiza form wooly covering of fungal
hyphae on the surface and remain in upper layers. It is of two types Ecto and
Endomycorrhiza. In some endomycorrhiza, the fungal hyphae develop some organs
called vesicles within the root cortical cells, such mycorrhizae are called VAM (vesicular
arbuscular mycorrhizae). It is meant for
phosphate nutrition.
44. The plasmid [1995] (a) helps in respiration
(b) genes found inside nucleus (c) is a component of cell wall of bacteria
(d) is the genetic part in addition to DNA in
micro-organisms Solution: (d)
The term ‗plasmid‘ was introduced by Lederberg in 1952 for extragenomic DNA
segment. It is a small circular molecule of DNA found in bacterial cell in addition to
the larger circular bacterial DNA.
45. Which of the following organism
possesses characteristics of both a plant and an animal?
(a) Bacteria
(b) Euglena
(c) Mycoplasma (d) Paramecium
Solution: (b) The Euglena is an organism, which
possesses both the characteristics of plants and animals, as it can move with a flagella
and also contains chlorophyll. Its nutrition is mixotrophic.
46. The function of contractile vacuole, in protozoa, is [1995]
(a) locomotion (b) food digestion
(c) osmoregulation (d) reproduction
Solution: (c) In protozoa, the function of contractile vacuole is the removal of excretory
substances, carbon dioxide etc. It is very essential to regulate water content i.e.,
osmoregulation.
47. Macro and micronucleus are the characteristic feature of [1995]
(a) Paramecium and Vorticella
(b) Opelina and Nictothisus (c) Hydra and Ballantidium
(d) Vorticella and Nictothirus Solution: (a) The macronucleus lacks nuclear membrane and is formed of
trophochromatin. It regulates the metabolic activities of the body and it is also known
as trophonucleus. The micronucleus has a
definite nuclear membrane and controls the reproductive activities of Paramecium
and Vorticella.
48. Excretion in Amoeba occurs through [1995]
(a) lobopodia
(b) uroid portion (c) plasma membrane
(d) contractile vacuole Solution: (d) The conractile vacuole is supposed to assist excertion in Amoeba, as its watery
contents possess traces of carbon dioxide and urea. The CO2 diffuses directly through
plasmalemma.
49. The organism, used for alcoholic
fermentation, is [1995]
Topicwise Solved Previous Year Qs 17
(a) Pseudomonas
(b) Penicillium (c) Aspergillus
(d) Saccharomyces Solution: (d) Fermentation refers to the breakdown of organic substances, particularly
carbohydrates, under anaerobic conditions. Saccharomyces cerevisiae is used for
fermenting carbohydrate. The ethyl alcohol
and carbon dioxide are formed at the end of the process.
50. Which of the following is not
correctly matched? [1995]
(a) root knot disease - Meloidogyne javanica (b) smut of bajra - Tolysporium penicillariae
(c) covered smut of barley - Ustilago nuda (d) late blight of potato - Phytophthora
infestans Solution: (c) Covered smut of barley is caused by Ustilago hordei, not by Ustilago nuda. This
disease is purely externally seed borned.
51. The chemical compounds produced
by the host plants to protect themselves against fungal infection is [1995]
(a) phytotoxin (b) pathogen
(c) phytoalexins (d) hormone
Solution: (c) Phytoalexins are non-specific antibiotic substances produced by plants in response
to infection by a fungus.
52. White rust disease is caused by [1995]
(a) Claviceps
(b) Alternaria (c) Phytophthora
(d) Albugo candida Solution: (d) Albugo candida is an obligate parasite causing white rust on members of family
Cruciferae and other hosts.
53. Azotobacter and Bacillus polymyxa
are the examples of [1996] (a) symbiotic nitrogen-fixers
(b) non-symbiotic nitrogen-fixers
(c) ammonifying bacteria
(d) disease-causing bacteria Solution: (b) Azotobacter and Bacillus polymyxa are the examples of non-symbiotic nitrogenfixers.
54. Sex factor in bacteria is [1996]
(a) Chromosomal replicon (b) F-replicon
(c) RNA
(d) Sex-pilus Solution: (b) Sex-factor or F-factor in bacteria results in high frequency conjugation. It allows
bacteria to produce sex pilus necessary for conjugation.
55. Influenza virus has [1996] (a) DNA
(b) RNA (c) both DNA and RNA
(d) only proteins and no nucleic acids. Solution: (b) Influenza virus is a retrovirus wherein, the genetic material comprises of RNA. There
are three genera of influenza virus,
identified by antigenic differences in their nucleoprotein and matrix protein: •
Influenza virus A are the cause of all flu pandemics and are known to infect
humans, other mammals and birds (see also avian influenza). • Influenza virus B
are known to infect humans and seals. • Influenza virus C are known to infect
humans and pigs.
56. In bacterial chromosomes, the
nucleic acid polymers are [1996] (a) linear DNA molecule
(b) circular DNA molecule (c) of two types-DNA and RNA
(d) linear RNA molecule
Solution: (b) Bacterial chromosomes comprise of
circular DNA.
57. Interferons are [1996] (a) antiviral proteins
(b) antibacterial proteins (c) anticancer proteins
(d) complex proteins
Solution: (a)
Topicwise Solved Previous Year Qs 18
Interferons are virus induced proteins
produced by cells infected with viruses. They are antiviral in action.
58. Which one of the following is not
true about lichens? [1996] (a) Their body is composed of both algal
and fungal cells (b) Some form food for reindeers in arctic
regions
(c) Some species can be used as pollution indicators
(d) These grow very fast at the rate of about 2 cm per year
Solution: (d) Lichens are composite dual organisms
formed by the association between a
fungus and a photosynthetic symbiont. The bulk of lichen body is formed of fungus.
59. Mycorrhiza is [1996]
(a) a symbiotic association of plant roots and certain fungi
(b) an association of algae with fungi (c) a fungus parasitising root system of
higher plants
(d) an association of Rhizobium with the roots of lenguminous plants
Solution: (a) Association of algae and fungi is referred to
as lichen. Symbiotic association of Rhizobium with roots of leguminous plants
is referred to as symbiosis. Mycorrhiza is symbiotic association between fungi and
roots of higher plants. The fungal partner of
mycorrhiza obtains food from roots of the higher plant and in return supplies mineral
elements to it.
60. The hereditary material present in the bacterium Escherichia coli is [1997,
98]
(a) single stranded DNA (b) deoxyribose sugar
(c) double stranded DNA (d) single stranded RNA
Solution: (c) In any kind of Bacteria (E.coli) double
stranded DNA is present.
61. The plasmids pesent in the bacterial
cells are [1997] (a) circular double helical DNA molecules
(b) circular double helical RNA molecules
(c) linear double helical DNA molecules
(d) linear double helical RNA molecules. Solution: (a) Plasmids are the extrachromosomal DNA.
62. Which one of the following statements about viruses is correct?
[1997] (a) Viruses possess their own metabolic
system
(b) Viruses contain either DNA or RNA (c) Viruses are facultative parasites
(d) Viruses are readily killed by antibiotics Solution: (b) Viruses have either DNA or RNA as the genetic material. Viruses having RNA as the
genetic material are known as Retroviruses.
63. Most of the Lichens consist of [1997]
(a) blue-green algae and basidomycetes (b) blue-green algae and ascomycetes
(c) red algae and ascomycetes (d) brown algae and phycomycetes
Solution: (b) The lichen fungus is typically a member of
the Ascomycota rarely a member of the
Basidiomycota. The algal or cyanobacterial cells are photosynthetic, and as in higher
plants they reduce atmospheric carbon dioxide into organic carbon sugars to feed
both symbionts. Both partners gain water and mineral nutrients mainly from the
atmosphere through rain and dust. The fungal partner protects the alga by
retaining water, serving as a larger capture
area for mineral nutrients and, in some cases, provides minerals obtained from the
substratum. If a cyanobacterium is present, as a primary partner or another
symbiont in addition to green alga as in certain tripartite lichens, they can fix
atmospheric nitrogen, complementing the
activities of the green alga.
64. Two bacteria found to be very useful in genetic engineering experiments are
[1998] (a) Escherichia and Agrobacterium
(b) Nitrobacter and Azotobacter (c) Rhizobium and Diplococcus
(d) Nitrosomonas and Klebsiella
Solution: (a) Escherichia and Agrobacterium are both
used as vectors in genetic engineering.
Topicwise Solved Previous Year Qs 19
Nitrobactor converts nitrites to nitrates.
Azotobacter is a free living nitrogen fixing bacteria. Nitrosomonas converts ammonia
to nitrite. Rhizobium is a symbiotic nitrogen fixing bacteria living in the root
nodules of leguminous plants Diplococcus pneumoniae causes pneumonia.
65. The main role of bacteria in the
carbon cycle involves [1998]
(a) photosynthesis (b) chemosynthesis
(c) digestion or breakdown of organic compounds
(d) assimilation of nitrogenous compounds Solution: (c) Bacteria acts as decomposers in the
carbon cycle.
66. A few organisms are known to grow and multiply at temperatures of 100–
105ºC. They belong to [1998] (a) marine archaebacteria
(b) thermophilic sulphur bacteria (c) hot-spring blue-green algae
(cyanobacteria)
(d) thermophilic, subaerial fungi Solution: (a) These are archaebacteria which can tolerate high temperature.
67. Transfer of genetic information from
one bacterium to another in the transduction process is through [1998]
(a) Conjugation
(b) Bacteriophages released from the donor bacterial strain
(c) Another bacterium (d) Physical contact between donor and
recipient strain Solution: (b) Transfer of genetic information from one
bacterium to another by physical contact is called conjugation while if it takes place by
some other medium like virus than it is called transduction.
68. Puccinia forms [1998]
(a) uredia and aecia on wheat leaves (b) uredia and telia on wheat leaves
(c) uredia and aecia on barberry leaves
(d) uredia and pycnia on barberry leaves Solution: (b)
Puccinia causes black rust of wheat. It
completes its life cycle in two hostswheat and barberry. Two types of spores are
produced on wheat - uredospores and teleutospores.
69. Which one of the following micro-
organisms is used for production of citric acid in industries?
(a) Penicillium citrinum
(b) Aspergillus niger (c) Rhizopus nigricans
(d) Lactobacillus bulgaris Solution: (b) Aspergillus niger is known as guinea pig of kingdom fungi. The main source of
commercial preparation of citric acid is the
fermentation of sugar with Aspergillus niger.
70. Yeast Saccharomyces cerevisiae is
used in the industrial production of [1998]
(a) citric acid
(b) tetracycline (c) ethanol
(d) butanol Solution: (c) Yeast performs alcoholic fermentation because of enzyme ‗Zymase‘. It is used in
the production of ethyl alcohol or ethanol.
71. Due to which of the following
organisms, yield of rice has been increased? [1999]
(a) Anabaena (b) Bacillus popilliae
(c) Sesbania (d) Bacillus polymexa
Solution: (a) Azolla is a freshwater fern harbouring a
bluegreen alga - Anabaena in its leaf
cavities. The alga fixes atmospheric nitrogen and releases nitrogenous
compounds in leaf cavities. This symbiotic system is the main source of algal
biofertilizer in rice fields. When rice paddies
Topicwise Solved Previous Year Qs 20
are flooded in the spring, they can be
inoculated with Azolla, which then quickly multiplies to cover the water, suppressing
weeds. As the plants die, they contribute nitrogen to the rice plants, and as the rice
paddy dries out, the Azolla all eventually die, making an exceptional green manure.
72. Photosynthetic bacteria have
pigments in [1999]
(a) leucoplasts (b) chloroplasts
(c) chromoplasts (d) chromatophores
Solution: (d) Chloroplasts, chromoplasts and
leucoplasts are the types of plastids found
in higher plants. Chloroplasts contain the green pigment chlorophyll. Chromoplasts
contain coloured pigments. Leucoplasts are colourless and store starch granules.
73. In prokaryotes, the genetic material
is [1999] (a) linear DNA with histones
(b) circular DNA with histones
(c) linear DNA without histones (d) circular DNA without histones
Solution: (d) In prokayotes nucleoid consist of double
stranded circular DNA without histone protein.
74. A good green manure in rice fields is
[2000]
(a) Aspergillus (b) Azolla
(c) Salvinia (d) Mucor
Solution: (b) Aspergillus is a fungus, Mucor is also a
fungus. Azolla harbours blue-green algae
Anabaena which fixes N2, increasing fertility.
75. Enzymes are absent in [2000]
(a) Cyanobacteria (b) Viruses
(c) Algae (d) Fungi
Solution: (b) Enzymes are absent in viruses because they are unable to transmit their nucleic
acid from one host cell to another.
76. A virus can be considered a living organism because it [2000]
(a) responds to touch stimulus (b) respires
(c) reproduces (inside the host) (d) can cause disease
Solution: (c) 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.
77. In fungi stored food material is [2000]
(a) glycogen
(b) starch (c) sucrose
(d) glucose Solution: (a)
Glycogen is a glucosan Ohomopolysaccharide which is the major
reserve food of animals, fungi and some bacteria. Starch is also glucosan
homopolysaccharide and is the major
reserve food of plants. Sucrose is formed of one molecule of glucose and one molecule
of fructose.
78. Black rust of wheat is caused by [2000]
(a) Puccinia (b) Mucor
(c) Aspergillus
(d) Rhizopus Solution: (a) Black rust of wheat is caused by Puccinia graminis. The symptoms are seen in stem
or leaf sheath as brownish spot. Yeast helps in ethyl alcohol formation.
79. Industrial production of ethanol from starch is brought about by [2000]
(a) Saccharomyces (b) Lactobacillus
(c) Azotobacter (d) Penicillium
Solution: (a) Lactobacillus is the milk bacteria while
Azotobacter is the free living nitrogen fixing
bacteria and Penicillium is the source of Penicillin.
Topicwise Solved Previous Year Qs 21
80. Interferons are synthesized in
response to (a) Mycoplasma
(b) Bacteria (c) Viruses
(d) Fungi Solution: (c) Interferons are virus induced proteins produced by cells infected with virus.
81. Extra-nuclear inheritance occurs in [2001]
(a) Killer strain in Paramecium (b) Colour blindness
(c) Phenylketonuria (d) Tay sach disease
Solution: (a) Colour blindness follows sex-linked inheritance. Phenylketonuria is an in born
error of metabolism.
82. What is true for cyanobacteria? [2001]
(a) Oxygenic with nitrogenase (b) Oxygenic without nitrogenase
(c) Non-oxygenic with nitrogen
(d) Non-oxygenic without nitrogenase Solution: (a) Cyanobacteria are oxygenic photoautotroph. Many members perform
nitrogen fixation.
83. What is true for archaebacteria? [2001]
(a) All halophiles
(b) All photosynthetic (c) All fossils
(d) Oldest living beings Solution: (d) Archaebacteria are the most ancient and halogenous group of bacteria and are called
living fossils.
84. Cauliflower mosaic virus contains
[2001] (a) ss RNA
(b) ds RNA (c) ds DNA
(d) ss DNA Solution: (c) Cauliflower mosaic virus contains double
stranded DNA.
85. What is true for plasmid? [2001]
(a) Plasmids are widely used in gene
transfer (b) These are found in virus
(c) Plasmid contains gene for vital activities (d) These are main party of chromosome
Solution: (a) Plasmids are small intranuclear circular
DNAs which carry extra chromosomal genes in bacteria.
86. Plant decomposers are [2001] (a) Monera and fungi
(b) Fungi and plants (c) Protista and animalia
(d) Animalia and monera Solution: (a) Plant decomposers are Bacteria (Kingdom
Monera) and Fungi.
87. Adhesive pad of fungi penetrates the host with the help of [2001]
(a) mechanical pressure and enzymes (b) hooks and suckers
(c) softening by enzymes (d) only by mechanical pressure
Solution: (a) The fungal hyphae secrete enzymes which convert insoluble complex food material in
the substratum to the soluble ones. The hyphae wall of intracellular hyphae come in
contact with the host protoplasm and obtain food by direct diffusion.
88. Some bacteria are able to grow in
Streptomycin containing medium due to
(a) natural selection (b) Induced mutation
(c) reproductive isolation (d) genetic drift
Solution: (a) Prevention of mating between two natural
populations of the same or different spaces
due to presence of barriers to interbreeding is called reproductive isolation. Genetic
drift is the random change in the allele number and frequency in a gene pool.
Natural selection is a type of force for evolutionary processes. Here in this case it
allows the growth of only those bacteria which have resistance towards
streptomycin.
89. Which bacteria is utilized in gober
gas plant?
Topicwise Solved Previous Year Qs 22
(a) Methanogens
(b) Nitrifying bacteria (c) Ammonifying bacteria
(d) Denitrifying bacteria Solution: (a) Methanobacillus (methanogen) occurs in marshes and also in dung. It produces CH4
gas under anaerobic condition and is utilized in gobar gas plant.
90. In bacteria, plasmid is [2002] (a) extra – chromosomal material
(b) main DNA (c) non-functional DNA
(d) repetitive gene
Solution: (a) Plasmid is attached to mesosome in
bacteria.
91. Which statement is correct for bacterial transduction? [2002]
(a) Transfer of some genes from one bacteria to another bacteria through virus
(b) Transfer of genes from one bacteria to
another bacteria by conjugation (c) Bacteria obtained its DNA directly
(d) Bacteria obtained DNA from other external source
Solution: (a) Transduction experiments were carried out
by Hershey and Chase.
92. Which of the following secretes
toxins during storage conditions of crop plants? [2002]
(a) Aspergillus (b) Penicillium
(c) Fusarium (d) Colletotrichum
Solution: (a) Aspergillus flavus produces carcinogenic fungus toxin (Aflatoxin) during storage
condition of crop plant.
93. Which fungal disease spreads by seed and flowers? [2002]
(a) Loose smut of wheat (b) Corn stunt
(c) Covered smut of barley
(d) Soft rot of potato Solution: (a)
Ustilago causes loose smut of wheat, as a
result the grain and flower get converted into powdered mass.
94. During the formation of bread it
becomes porous due to release of CO2 by the action of
(a) Yeast (b) Bacteria
(c) Virus
(d) Protozoans Solution: (a) Yeast carry out fermentation, releasing CO2 making bread soft and porous. Hence
Saccharomyces is referred to as baker‘s yeast.
95. The chief advantage of encystment to an Amoeba is [2003]
(a) the chance to get rid of accumulated waste products
(b) the ability to survive during adverse physical conditions
(c) the ability to live for sometime without ingesting food
(d) protection from parasites and predators
Solution: (b) Encystment enables the zygote to survive
under adverse or infavourable conditions wherein it lies dormant.
96. Viruses are no more ―alive‖ than
isolated chromosomes because [2003] (a) both require the environment of a cell to
replicate
(b) they require both RNA and DNA (c) they both need food molecules
(d) they both require oxygen for respiration Solution: (a) Viruses can live only inside the host cell, using their machinery for its own
metabolism.
97. Chromosomes in a bacterial cell can
be 1 – 3 in number and [2003] (a) can be circular as well as linear within
the same cell (b) are always circular
(c) are always linear (d) can be either circular or linear, but
never both with in the same cell
Solution: (b) Prokaryotes (bacteria) have only circular
chromosomes.
Topicwise Solved Previous Year Qs 23
98. Which one of the following statements about viruses is correct?
[2003] (a) Nucleic acid of viruses is known as
capsid (b) Viruses possess their own metabolic
system (c) All viruses contain both RNA and DNA
(d) Viruses are obligate parasites
Solution: (d) Virus is a nucleoprotein entity which
becomes active only inside a living cells utilizing the latter machinery for
multiplication. Capsid is the protein covering around the genetic material.
99. Tobacco mosaic virus is a tubular filament of size [2003]
(a) 700 × 30 nm (b) 300 × 10 nm
(c) 300 × 5 nm (d) 300 × 20 nm
Solution: (d) Tobacco mosaic virus is 300 nm long and
20 nm in diameter.
100. Lichens are well known
combination of an alga and a fungus where fungus has [2004]
(a) a saprophytic relationship with the alga (b) an epiphytic relationship with the alga
(c) a parasitic relationship with the alga (d) a symbiotic relationship with the alga
Solution: (d) Lichens are composite dual organisms formed by symbiotic association between a
fungus and alga. A saprophyte is an organism feeding on dead, decaying organic
matter. Epiphyte is a plant growing over another plant. Parasites live inside their
host.
101. Which one of the following pairs is
not correctly matched? [2004] (a) Streptomyces - Antibiotic
(b) Serratia - Drug addiction (c) Spirulina - Single cell protein
(d) Rhizobium - Biofertilizer Solution: (b) Rhizobium is a symbotic nitrogen fixing
bacteria. Streptomyces is source for streptomycin. Spirulina is a rich source of
vitamin B1 and proteins.
102. Which of the following statements is not true for retroviruses? [2004]
(a) DNA is not present at any stage in the life cycle of retroviruses
(b) Retroviruses carry gene for RNAdependent DNA polymerase
(c) The genetic material in mature retroviruses is RNA
(d) Retroviruses are causative agents for
certain kinds of cancer in man Solution: (a) Retroviruses have RNA as the genetic material and hence they exhibit reverse
transcription whereby DNA is synthesized on RNA template. They have reverse
transcriptase as the enzyme.
103. The most thoroughly studied fact
of the known bacteria-plant interactions is the [2004]
(a) cyanobacterial symbiosis with some aquatic ferns
(b) gall formation on certain angiosperms by Agrobacterium
(c) nodulation of Sesbania stems by
nitrogen fixing bacteria (d) plant growth stimulation by
phosphatesolubilising bacteria Solution: (b) This phenomenon has been successfully used in genetic engineering to produce
disease resistant varieties of plants.
104. Viruses that infect bacteria,
multiply and cause their lysis, are called [2004]
(a) lysozymes (b) lipolytic
(c) lytic (d) lysogenic
Solution: (c) Viruses that get integrated with the bacterial host genome are called lysogenic.
Virus which transmit its DNA into bacterial cell and divide within bacterial cell causing
breakdown of bacterial cell wall are called lytic virus. Lysozymes are present in the
lipolytic enzymes catalyses breakdown of fats (Lipids).
105. Auxopores and hormocysts are formed, respectively, by: [2005]
(a) Some diatoms and several cyanobacteria
Topicwise Solved Previous Year Qs 24
(b) Some cyanobacteria and diatoms
(c) Several cyanobacteria and several diatoms
(d) Several diatoms and a few cyanobacteria.
Solution: (d) Binary fission in diatoms reduces the size
of most daughters which is corrected through the development of auxospores. In
some filamentous cyanobacterial forms
unisexual reproduction occurs by hormogonia (hormocysts). They are
identified by presence of biconcave (one disk or separation disc between two
adjacent cells e.g. Oscillatoria).
106. All of the following statements
concerning the Actinomycetes filamentous soil bacterium Frankia are
correct except that Frankia: [2005] (a) Can induce root nodules on many plant
species (b) Cannot fix nitrogen in the free-living
state. (c) Forms specialized vesicles in which the
nitrogenase is protected from oxygen by a
chemical barrier involving triterpene hopanoids
(d) Like Rhizobium, it usually infects its host plant through root hair deformation
and stimulates cell proliferation in the host‘s cortex
Solution: (b) Frankia, is a nitrogen fixing mycelial
bacterium which is associated
symbiotically (and not free living) with the root nodules of several non legume plants.
107. For retting of jute the fermenting
microbe used is [2005] (a) Methophilic bacteria
(b) Butyric acid bacteria
(c) Helicobactor pylori (d) Streptococcus lactin
Solution: (b) Butyric acid bacteria, Clostridium
butylicum causes the retting of fibres. Retting is a stage in the manufacturing of
vegetable fibers, especially the bast fibers. It is the process of submerging plant stems
such as flax, jute, hemp or kenaf in water,
and soaking them for a period of time to loosen the fibers from the other
components of the stem. Retting can also
be done by letting the cut crop stand in the
fields in the wet fall, called ―dew retting‖. Bacterial action attacks pectin and lignin,
freeing the cellulose fibres. The stems are then removed and washed and subject to
mechanical processing to remove the soft tissue and then dried so that all that
remains are the fibres.The process is caused by Closteridium butylicum.
108. There exists a close association between the alga and the fungus within a
lichen. The fungus [2005] (a) provides protection, anchorage and
absorption for the alga (b) provides food for the alga
(c) fixes the atmospheric nitrogen for the
alga (d) releases oxygen for the alga
Solution: (a) Lichens (coined by Theophrastus) are
composite or dual organisms which are formed by a fungus partner or mycobiont
(mostly ascomycetes) and an algal partner (mostly blue green algae). Fungus forms the
body of lichen as well as its attaching and
absorbing structures. Algae performs photosynthesis and provides food to the
fungus.
109. Which antibiotic inhibits interaction between RNA and mRNA
during bacterial protein synthesis? [2006]
(a) Neomycin
(b) Streptomycin (c) Tetracycline
(d) Erythromycin Solution: (a) Neomycin is the antibiotic which inhibit the translation of bacterial cell so that it
can not affect the host cell.
110. Which of the following statements
regarding cilia is not correct? [2006] (a) Cilia are hair-like cellular appendages
(b) Microtubules of cilia are composed of tubulin
(c) Cilia contain an outer ring of nine doublet microtubules surrounding two
single microtubules
(d) The organized beating of cilia is controlled by fluxes of Ca2+ across the
membrane
Topicwise Solved Previous Year Qs 25
Solution: (a) Eukaryotic cilia are made up of tubulin protein. Cilia have a core of 2 microtubules
and around there are 9 doublet microtubules. These are not at all hair like
structures.
111. The thalloid body of a slime mould (Myxomycetes) is known as [2006]
(a) plasmodium
(b) fruiting body (c) mycelium
(d) protonema Solution: (a) The thalloid body of slime moulds is made up of multinucleated cell which lacks septa
in between and hence it is a multinucleated
single celled mass called plasmodium.
112. 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 Choose the answer from the following options:
[2006] (a) A, D and E only
(b) B, D and E only (c) B, C and F only
(d) A, C and E only Solution: (a) Mucor is a fungus and most of the fungi
require the optimum temperature of about 15-30ºC, good moisture content in
atmosphere and not very dark and not very lightened place. So the Mucor requires a
temperature of about 25ºC, humidity about 95% and a shady place to grow fully.
113. The causative agent of mad-cow disease is a
(a) Prion (b) Worm
(c) Bacterium (d) Virus
Solution: (a) Mad cow disease is actually Bovine
Spongiform Encephalopathy or BSE. In this
disease cattles in Britain got their brain become spongy & ultimately gradual
degradation of nervous system. It is caused
by some virus like but nucleic acid devoid
proteinaceous particles called prions (proteinaceous infectious particle).
114. Which one of the following
statements about mycoplasma is wrong? [2007]
(a) They are pleomorphic (b) They are sensitive to penicillin
(c) They cause diseases in plants
(d) They are also called PPLO. Solution: (b) While working at the Rockefeller Institute, Brown reported isolation of a PPLO from
human arthritic joint tissue in 1938. In 1949, Diennes reported to the 7th
International Rheumatology Congress the
isolation of PPLO from the genitourinary tracts of men afflicted with arthritis. In
discussing the significance of this observation, Brown reported successful
treatment of arthritic patients in 1949 with a new antibiotic called aureomycin (Clark,
1997).
115. Which pair of the following belongs
to Basidiomycetes [2007] (a) puffballs and Claviceps
(b) peziza and stink borns (c) Morchella and mushrooms
(d) birds nest fungi and puffballs. Solution: (d) The class Basidiomycetes includes those members that produce their basidia and
basidiospores on or in a basidiocarp.
116. Ergot of rye is caused by a species
of [2007] (a) uncimula
(b) ustilago (c) claviceps
(d) phytophthora.
Solution: (c) Ergot of Rye is a plant disease that is
caused by the fungus Claviceps purpurea. The so-called ergot that replaces the grain
of the rye is a dark, purplish sclerotium, from which the sexual stage, of the life
cycle will form after over wintering.
117. Which one of the following is a
slime mould? [2007] (a) Physarum
(b) Thiobacillus
Topicwise Solved Previous Year Qs 26
(c) Anabaena
(d) Rhizopus Solution: (a) Physarum polycephalum belongs to phylum Amoebozoa, infraphylum
Mycetozoa, and class Myxogastrea. P. polycephalum, often referred to as the
―many-headed slime,‖ is a slime mold that inhabits shady, cool, moist areas, such as
decaying leaves and logs.
118. Which one of the following is linked
to the discovery of Bordeaux mixture as a popular fungicide? [2008]
(a) Bacterial leaf blight of rice (b) Downy mildew of grapes
(c) Loose smut of wheat
(d) Black rust of wheat Solution: (b) Downy mildew of grapes disesase is linked to the discovery of Bordeux mixture as a
popular fungicide. Bordeux mixture was discovered by Millardet in France in 1882.
Bordeux mixture is prepared by dissolving 40g. of copper sulphate and 40 g of calcium
hydroxide in 5 litres of water. Bordeux
mixture is used primarily as a fungicide, it was first used to control downy mildew
disease of grape-vine caused by a fungus, Plasmopara viticola. The first pesticide to
be used commercially was bordeux mixture.
119. Bacterial leaf blight of rice is
caused by a species of [2008]
(a) Xanthomonas (b) Pseudomonas
(c) Alternaria (d) Erwinia
Solution: (a) Bacterial leaf blight of rice is caused by a
species of Xanthomonas. Mature rice plant
infected by these bacteria, lesion begins as water soaked stripes on the leaf blades and
eventually would increase in length and width becoming yellow to grayish-white
until the entire leaf dries up.
120. 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? [2008]
(a) Archaea resemble eukarya in all
respects (b) Archaea have some novel features that
are absent in other prokaryotes and eukaryotes
(c) Archaea completely differ from both prokaryotes and eukaryotes
(d) Archaea completely differ from prokaryotes.
Solution: (b) A domain of prokaryotic organisms containing the archaebacteria including the
methanogens, which produce methane; the thermoacidophilic bacteria, which live in
extremely hot and acidic environments, & the halophilic bacteria, which can only
function at high salt concentrations are
abundant in the world‘s oceans.
121. Thermococcus, Methanococcus and Methanobacterium exemplify: [2008]
(a) Archaebacteria that contain protein homologous to eukaryotic core histones
(b) Archaebacteria that lack any histones resembling those found in eukaryotes but
whose DNA is negatively supercoiled
(c) Bacteria whose DNA is relaxed or positively supercoiled but which have a
cytoskeleton as well as mitochondria (d) Bacteria that contain a cytoskeleton and
ribosomes Solution: (a) Thermococcus, Methanococcus and Methano bacterium exemplify
archaebacteria that contain protein
homologous to eukaryotic core histones.
122. Which one is the wrong pairing for the disease and its causal organism?
[2009] (a) Black rust of wheat - Puccinia graminis
(b) Loose smut of wheat - Ustilago nuda
(c) Root-knot of vegetables - Meloidogyne sp (d) Late blight of potato - Alternaria solani
Solution: (d) Late blight is caused by the fungus Phy-
tophthora infestans. Late blight appears on potato or tomato leaves as pale green,
water-soaked spots, often beginning at leaftips or edges. The circular or irregular
leaf lesions are often surrounded by a pale
yellowishgreen border that merges with healthy tissue. Lesions enlarge rapidly and
turn dark brown to purplish-black. During
Topicwise Solved Previous Year Qs 27
periods of high humidity and leaf wetness,
a cottony, white mold growth is usually visible on lower leaf surfaces at the edges of
lesions. In dry weather, infected leaf tissues quickly dry up and the white mold growth
disappears. Infected areas on stems appear brown to black and entire veins may be
killed in a short time when moist weather persists.
123. Phylogenetic system of classification is based on: [2009]
(a) morphological features (b) chemical constituents
(c) floral characters (d) evolutionary relationships
Solution: (d) Phylogenetic system of classification is based on evolutionary relationships. This
phylogenetic classification system names only clades-groups of organisms that are all
descended from a common ancestor. Under a system of phylogenetic classification, we
could name any clade on this tree. For example, the Testudines, Squamata,
Archosauria, and Crocodylomorpha all
form clades.
124. Mannitol is the stored food in: [2009]
(a) Porphyra (b) Fucus
(c) Gracillaria (d) Chara
Solution: (b) Mannitol is a food stored in Fucus. Fucus is a genus of brown alga in the class
Phaeophyceae to be found in the intertidal zones of rocky seashores almost everywhere
in the world. Primary chemical constituents of this plant include mucilage, algin,
mannitol, betacarotene, zeaxanthin, iodine,
bromine, potassium, volatile oils, and many other minerals.
125. Single-celled eukaryotes are
included in: (a) Protista
(b) Fungi (c) Archaea
(d) Monera
Solution: (a) Single celled eukaryotes are included in
protista. Protista includes all unicellular
and colonial eukaryotes except green and
red algae. It is also known as kingdom of unicellular eukaryotes.
126. Ringworm in humans is caused by:
[2010] (a) Bacteria
(b) Fungi (c) Nematodes
(d) Viruses
Solution: (b) Ring worm is a fungal disease caused by
the dermatophyte fungi species of microsporum, trichophyton and
epidermophyton.
127. Membrane-bound organelles are
absent in: [2010] (a) Saccharomyces
(b) Streptococcus (c) Chlamydomonas
(d) Plasmodium Solution: (b) Membrane bound organelles are absent in Streptococcus. Streptococcus is a
bacterium that is included under kingdom
Monera. Monerans are prokaryotes which lack membrane bound organelles like
mitochondria, E.R, Golgi etc. Saccharomyces, Chlamydomonas and
Plasmodium are eukaryotes that have membrane bound organelles.
128. Virus envelope is known as: [2010]
(a) Capsid
(b) Virion (c) Nucleoprotein
(d) Core Solution: (a) Virus envelope is known as capsid. The capsid is composed of protein subunits
called capsomere.
129. Which one of the following is not a
biofertilizer? [2011] (a) Agrobacterium
(b) Rhizobium (c) Nostoc
(d) Mycorrhiza Solution: (a) Agrobacterium is a soil borne pathogen
responsible for affecting many higher species of plant. But Rhizobium, Nostoc
and Mycorrhiza are biofertilizers.
Topicwise Solved Previous Year Qs 28
130. Ethanol is commercially produced through a particular species of: [2011]
(a) Saccharomyces (b) Clostridium
(c) Trichoderma (d) Aspergillus
Solution: (a) Saccharomyces cerevisiae is commercially
used to produce ethanol. S. cerevisiae is a
yeast which helps in alcoholic fermentation in which sugars such as glucose, fructose
and sucrose are converted into cellular energy and produce ethanol.
131. Which one of the following
organisms is not an example of
eukaryotic cells? [2011] (a) Paramecium caudatum
(b) Escherichia coli (c) Euglena viridis
(d) Amoeba proteus Solution: (b) E. coli is a prokaryotic celled gram negative bacterium.
132. Archegoniophore is present in: [2011]
(a) Marchantia (b) Chara
(c) Adiantum (d) Funaria
Solution: (a) Archegoniophore is the female sex organ of
bryophytes (Marchantia) and pteridophytes.
Its neck region is made up of 4-6 vertical rows of cells.
133. In eubacteria, a cellular component
that resembles eukaryotic cells is: [2011] (a) plasma membrane
(b) nucleus
(c) ribosomes (d) cell wall
Solution: (a) Eubacteria are prokaryotic but eubacteria
are enclosed by plasma membrane like eukaryotic cells.
134. Compared with the gametophytes
of the bryophytes the gametophytes of
vascular plant are [2011] (a) smaller but have larger sex organs
(b) larger but have smaller sex organs
(c) larger and have larger sex organs
(d) smaller and have smaller sex organs Solution: (a) The gametophyte of bryophytes are smaller but have large sex organs.
135. The gametophyte is not an
independent, free living generation in: [2011]
(a) Polytrichum
(b) Adiantum (c) Marchantia
(d) Pinus Solution: (d) Gametophyte is not an independent free living generation in Pinus.
136. Organisms called methanogens are most abundant in a: [2011]
(a) sulphur rock (b) cattle yard
(c) polluted stream (d) hot spring
Solution: (b) Methanogens are archaebacteria abundant
in cattle yard and paddy fields.
137. Which one of the following pairs is
wrongly matched while the remaining three are correct? [2011M]
(a) Penicillium - Conidia (b) Water hyacinth - Runner
(c) Bryophyllum - Leaf buds (d) Agave - Bulbils
Solution: (b) Water hyacinth is a free floating perennial plant, can grow to a height of 3 feet.
138. Consider the following four
statements whether they are correct or wrong? (A) The sporophyte in liverworts
is more elaborate than that in mosses (B)
Salvinia is heterosporous (C) The life cycle in all seed-bearing plants is
diplontic (D) In Pinus male and female cones are borne on different trees
[2011M] (a) Statements (A) and (C)
(b) Statements (A) and (D) (c) Statements (B) and (C)
(d) Statements (A) and (B)
Solution: (b) (A) Sporophyte is more developed in
mosses rather than liverwort. (B) Pinus is
Topicwise Solved Previous Year Qs 29
monoecious in which male & female cones
are borne on different branches.
139. Selaginella and Salvinia are considered to represent a significant
step toward evolution of seed habit because: [2011M]
(a) female gametophyte is free and gets dispersed like seeds
(b) female gametophyte lacks archaegonia
(c) megaspores possess endosperm and embryo surrounded by seed coat
(d) embryo develops in female gametophyte which is retained on parent sporophyte.
Solution: (d)
140. Compared with the gametophytes of the bryophytes the gametophytes of
vascular plant are [2011] (a) smaller but have larger sex organs
(b) larger but have smaller sex organs (c) larger and have larger sex organs
(d) smaller and have smaller sex organs Solution: (a) The gametophyte of bryophytes are smaller
but have large sex organs.
141. The most abundant prokaryotes helpful to humans in making curd from
milk and in production of antibiotics are the ones categorised as: [2012]
(a) Cyanobacteria (b) Archaebacteria
(c) Chemosynthetic autotrophs
(d) Heterotrophic bacteria Solution: (d) The most abundant prokaryotes helpful to humans in making curd from milk and in
production of antibiotics are the heterotrophic bacteria. Lactobacillis
bacteria convert milk into curd.
142. The cyanobacteria are also referred
to as [2012] (a) protists
(b) golden algae (c) Slime moulds
(d) blue green algae Solution: (d) Cyanobacteria are also referred as blue
green algae, they perform oxygenic photosynthesis. They are most successful
autotrophic organisms on earth which one
found in all types of environment - fresh
water, sea water, salt marshes, moist rocks, tree trunks, moist soils, hot springs,
frozen waters.
143. Which statement is wrong for viruses [2012]
(a) All are parasites (b) All of them have helical symmetry
(c) They have ability to synthesize nucleic
acids and proteins (d) Antibiotics have no effect on them
Solution: (b) All the viruses are obligate parasite i.e.
they remain inert outside the host cell. They have ability to syntheize nucleic acids
and proteins by using host cellular
machinery (ribosomes, tRNAs, aminoacids, energy). Three shapes are found in viruses
helical (elongate body e.g. T.M.V) cuboidal (short broad body with rhombic rounded,
polyhedral shape e.g. Poliomyelitis virus) and binal (with birth cuboidal and helical
parts e.g. many bacteriophages like T2). Antibiotics have no effect on them, antiviral
drugs can only kill them.
144. Which one single organism or the
pair of organisms is correctly assigned to its taxonomic group [2012]
(a) Paramoecium and Plasmodium belong to the same kingdom as that of Penicillium
(b) Lichen is a composite organism formed from the symbiotic association of an algae
and a protozoan
(c) Yeast used in making bread and beer is a fungus
(d) Nostoc and Anabaena are examples of protista
Solution: (c) Saccharomyces cervisiae is a yeast used in
making bread (Baker‘s yeast) and
commercial production of ethanol. Paramoecium & Plasmodium are of animal
kingdom while pencillium is a fungi. Lichen is composite organism formed from the
symbiotic association of an algae and a fungus. Nostoc & Anabaena are examples
of kingdom monera.
145. How many organisms in the list
given below are autotrophs? Lactobacillus, Nostoc, Chara,
Nitrosomonas, Nitrobacter,
Topicwise Solved Previous Year Qs 30
Streptomyces, Saccharomyces,
Trypanosomes, Porphyra, Wolffia [2012M]
(a) Four (b) Five
(c) Six (d) Three
Solution: (c) Autotrophs are those organisms that are
able to make energy-containing organic
molecules from inorganic raw material by using basic sunlight. Nostoc, Chara,
Porphyra and Wolffia are photoautotrophs while Nitrosomonas and Nitrobacter are
chemoautotrophs.
146. In the five-kingdom classification,
Chlamydomonas and Chlorella have been included in [2012M]
(a) protista (b) algae
(c) plantae (d) monera
Solution: (b) Chlamydomonas & Chlorella have been
included in algae. Algae are chlorophyllus,
thalloid avascular plants with no cellular differentiation. Algae belong to thallophyta
of plant kingdom.
147. Which one of the following sets of items in the options 1 - 4 are correctly
categorized with one exception in it? Items- Category- Exception [2012M]
(a) UAA, UAG, UGA -Stop codons -UAG
(b) Kangaroo, Koala, Wombat -Australian marsupials -Wombat
(c) Plasmodium, Cuscuta, Trypanosoma -Protozoan parasites- Cuscuta
(d) Typhoid, Pneumonia, Diphtheria -Bacterial diseases -Diphtheria
Solution: (c) UAG is also a stop codon. Wombats are also Australian marsupials. They are short-
legged, muscular quadrupeds, approximately 1 metre (40 in) in length
with a short, stubby tail. Diphtheria is an acute infectious disease caused by the
bacteria Corynebacterium diphtheriae. Cuscuta, or Dodder plant, is not a
protozoan. It is a parasitic vine that wraps
around other plants for nourishment.
148. Which of the following are likely to
be present in deep sea water? [NEET 2013]
(a) Eubacteria (b) Blue-green algae
(c) Saprophytic fungi (d) Archaebacteria
Solution: (d) Archaebactera live in some of the most
harsh habitats such as extreme salty areas
(halophiles), hot springs (thermoacidophiles) and marshy areas
(methanogens) and in deep sea water.
149. Which one of the following is true for fungi? [NEET Kar. 2013]
(a) They are phagotrophs
(b) They lack a rigid cell wall (c) They are heterotrophs
(d) They lack nuclear membrane Solution: (c)
Fungi lack chlorophyll, hence, they do not prepare their food by photosynthesis. They
can grow where organic material is available. So, they are heterotrophs that
acquire their nutrient by absorption and
store in the form of glycogen.
150. Specialized cellsfor fixing atmospheric nitrogen in Nostoc are
[NEET Kar. 2013] (a) Akinetes
(b) Heterocysts (c) Hormogonia
(d) Nodules
Solution: (b) Heterocysts are large sized, thick-walled
specialised cells which occur in terminal, intercalary or lateral position in
filamentous cyanobacteria, e.g., Nostoc. They have enzyme nitrogenase and
specialised to perform biological nitrogen
fixation.
151. Satellite RNAs are present in some [NEET Kar. 2013]
(a) Plant viruses (b) Viroids
(c) Prions (d) Bacteriophages
Solution: (a) Plant viruses often contain parasites of their own, referred to as satellites. Satellite
RNAs are dependent on their associated
Topicwise Solved Previous Year Qs 31
(helper) virus for both replication and
encapsidation. Example—Tobacco Necrosis Virus (TNV). Viroids are infectious agents
smaller than viruses. Bacteriophages are viruses that infect the bacteria. A prion is
an infectious agent that is composed primarily of protein. : 3