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lyn (Dcule
-2,
zL ln/ u
ep code: 780300
F.Y.B.Sc. Biotechnology Semester t Examination
paper: Basic rife sciences r: Biodiversity
& ceil Biotogy
ModelAnswers
Q
1. Do as directed. (ANy
FTFTEEN) 1 MARK
EACH
(15)
Fillin the blanks:
l.Archaebacteria
2.Cartilaginous
3. Hemocyanin
4. Lysozyme
5. Peptidoglycan
6. Ribosomes
7. Phosphate
8. Rough
9. Gas Vacuoles
10. Felix d'Herelle
L1. Example of viruses with icosahedral symmetry
-
Adenoviruses, polioviruses
12 Spore production, spore dispersal
13' Example of bacteria with chemotrophic mode of nutrition
-Methanogens, Halophiles,
sulphur oxidizing or reducing bacteria, Nitrifiers, lron and Manganese
oxidizing bacteria.( E.coli,
N it ro so m o n a s, p s u d o m o n a s, D e su lfovi b r i o etc)
14' Globalwarming, pollution, climatic change, invasion of species,
deforestation, urbanization
etc
15. Mushrooms, molds, yeasts etc
L6. First virus to be studied by electron microscope
-
Tobacco mosaic virus (TMV)
l7'Taxonomic diversityrefers
to number and relative
abundance of species
in a community.
l8'The occulrence of two
or more forms differentlyproduced
in the lifecycle of a plant
usually invorving the regular
or animal
arternation between ,L*rur
uoJ usexual forms.
19' The yield of phage per
bacterium during virar murtiprication
cycre is cared the burst
size.
20' Pfant viruses can be cultivated
by direct mechanicat inoculation
of virus suspensions by
of living plants. rhis rubbing
is accomptished with
the aid of an abrasive such
::::ffiil'rtl:t
Q2
a. Write a note on
Millers experiment
(S
MARKS)
The experiment used water
materials which were belie
At the end of one week of co
cooled water, that as much
as
organic compounds. Two per
that are used to make proteins
The molecu
but
Uitilai"L fr"
systenr,
molecules, far from a complete
living biochemical
the hlPothetical
synthesize
rn"- ulrtltesses
could produce some
Q 2 b. Describe the Salient features
of chordate
(any seven points)
7
Marla
some chordates.
develops into
entral nervous
the brain and spine.
11steg:
develop into giit
arches
*;-*y
Hrt
uoo intn
d of the body, being absent
in humans
Dorsal hoflow
Notochord
ed structure that is found
in the
ome chordate species. It is
g skeletal support through
the
prrmary axial support of the
i;,*fiUl,ffitm'#X1i
Dorsal Hollow Nerve
ttfr:'#l;J*
notochord, however, is repraced
by the verrebrar
Cord
In chordates' it is located dorsally (at
the top ofthe animar) to the notoch.rd.
In contrast to the
'e characterized
by solid nerve cords that are l0cated
either
cord found in most chordate embryos
a.,r.Lp, into-ire urain and
central nervous system.
Pharyngeal slits are openings in the
pharym
to the outside environment. In
organi*r,
just posterior to the mouth)
that extend
lll" region
d"dti;
ttrut'tiu.
iiiooo-.rr,r;, pharyngeal slits
allow for the exit of water that eriters
the mouth during feeding,. In
vertebrate fishes, the
pharyngeal slits deverop into gilr
u."tt"r, tn" bony or cartilaginous gil
supports.
Q 2 c, Give Salien( features of gynnosperms (g
Marks)
(Any eight distinguishing points)
1,
gvoTueo.trmt qg1"Ti1- n$.d, s?erm.a: seed).are
naked - seeded:plan1s. Here rhe ovutes
not enclosed and thus the seeds ,.rnu-io
are
naked.
2' Most of the gynnosperms are evergreen,
woody perennials with shruby or tree
o-like
They show xerophytic claracters.
3' The main plant body is a well differentiated
sporophye consisting of root, stem and
Gametophyte is reduced and is aepenOent
on sporophyte.
4. Plants possess well developed root
system.
5. Leaves are
oftwo tlpes i.e. fotiage
leaves and scale leaves.
6. Vascular bundles are conjoint, collateral,
open and endarch.
7. Xylem consists of only tracheids.
8. Vessels are absent except in Gnetum.
habit.
leaves.
9. Companion cells are absent.
10. Secondary growth takes place both in roots
and stems.
I 1' Reproductive parts are E;enerally in the form of
compact and hard cones or strobili. The cones
are generally unisexual.
12' In male cones, many miicrosporphylls are arranged
on a central axis. Microsporophyll,s bear
micro sporangia containing microspores or pollen giains.
13. Archegonia lack neck canal cells.
14. Pollination is of anemophilous t1,pe.
15' The ovules are coverect by single integument and are
orthotropous type. The olule is a
modified mega sporangium rrorne directly on th. surface of megasporophyll."
16. Endosperm is formed be;lore fertilization.
17. Polyembryony is exhibitr:d by many members
of gymnosperms.
18' Embryo is formed inside the owle. The ovule gets
transformed into seed.
19. Epigeal mode of germination is seen.
20. Plants show distinct alternation of generation.
Cycas (Sago palm)
Q 2 d. Discuss the Generar aharacteristics of Eubacteria (z marks)
(any 7 distinguishing chararcters)
i
'
Bacteria
plokaryotic organisms (Kingdom:Monera), without cell
deflred organelles
1e
like mitochondria,Golgi bodies,Endoplasmic reticulum.,etc
'
'
Microscopic,unicellular,they may occur singly or aggregations to
form colonies.
They possess rigid cell vrall. Cell wall is made up of peptidoglycan
(Mureins) and Lipo
polysaccharides.
'
.
.
'
Absence of well defined nucleus.i.e., DNA is not enclosed in a
nuclear membrane.
.
Ribosomes are scattered in the cloplasmic matrix and are of z()s
type.
The plasma membrane is invaginated to form mesosomes.
Most of the bacteria are heterotrophic.Some bacteria are autotrophic,
bacteriochlorophyll, which is not in plastids.Instead it is found scattered.
Motile bacteria possess one or more flagella.
possess
a
The common method of multiplication
is binary fission.
o
lmffiT.r"r1r,..*Hla3kine,butgeneticrecombinationoccursbyconjugation
Q3
a' Describe the structure of Gram negative
bacteriar cet wa, (g Marks)
11_1*o"trribe
the fruid m'saic moder of pfasma
membrane (7 marks)
htt"r|*g{;f$l &*r:q t*th*s
{*\c S* Rttlr ss$, #r}
ofgl llrffrfl *nd t}**p'nrg
d
lhpm,$ttw
)$!w*K.
{le;;
ffi
Sl
a*r
niq$'\wr$,
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vifh*s
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r*sti
oiel*r*teail*el
f?x),
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lhr"
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on lhm *umr
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A
tufn
ee {$;a*
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Sy ffirymr
Q.{:Yr
+b{i$g
r**r*{$.*',t&o$***
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rt
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ir.
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qf qrtr
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itff
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r... .^
jt.
Q 3 c. Explain the process of endospore
formation (g marks)
Il-tri.:...
'
,;i
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i:
.ir
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'sp{r,\3
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:\..1
..'"'i.q.,.,r1 ..,
.,
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l
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c;$t*:r
$V$lF\#$iJ€t*
'r,,r:
,:iii{.
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,,rrls,
' '* ;\..i\
:r'
q 3 d. Describe the structure
of microtubufes ( 7 marks)
ili
s$
s
rlL$
tr,
5 gint irl
.,
n
I
it
'ss
ll
r
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rlu, ? i;r
t)r>fu&ir:irle.
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*l ir r"i
ili
t rH{.*4nar.\i*s,,
lnt*encr.ri*s, :Fa$k
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Q 4 a.
with
a herp of a diagram eraborate
on virat murtiprication cycre (g
marks)
..afMnnrReptitatiqn
'n*ii1s'd=,
@
The sequence of events initiated
by the injection of
the release of newly synthesi:zed
as
It can be plotted as one step
multiplication cycle as
production
virions is termed
nating in
on cycle.
ribes the
of progeny virions by cells as a function
of time after infection under one
step
conditions ( i'e' the cells are iinfected
is
eliminated by dilution).
simultaneously and secondary infection
by progeny virus
specifically during the first 10 minutes
or so after the injection of phage
DNA, no phage can be
recovered by disrupting the infected
bacterium. This is termed the ecripse
period. At the end of
theis period' mature phages begin
to accumulate intraceilurarry untir they
are rereased by cerl
lysis' No newly released extracellular
phages can be seen until
lysis begins; the time from
injection until the lysis is the latent period.
The extraceilurar phage number
increases untir it
reaches a constant titer at the ned
of the multiplication cycle; this time
interval is termed as rise
period'
The yield of phage prer bacterium
is called the burst size. This procedure
affords
observation of a single cycle of bacteriophage
growth.
Q4 b. Describe in detaif any two methods
for curtivation of animat virus ( 7
marksl
Methods for cultivation of animal viruses (
any two methods)
1' Embrvonated chicken esss -- one
of the most economicar and convenient
method is chick
in
chicken eggs incubated for 5_12
days can be
.rs]r. _Fertire
inocutated through the sher asepticarv.
The openins
egg incubated at 35 degree celsius
for the time required for the growth
of virus. chick embryo
contain several different types rcf
cells in which various viruses will
replicate. By using embryos
:J:H:":T:::::::",::::1
may;;;;;;;';.r#;It;T;:
of various ages and differeint method
of inoculation, it is possible to grow the
type of virus
desired' The cells to be in.culated
are found in various embryonic
membranes and tissues of
egg' For example' vaccinia virus can
be grown on chorioailantoic membrane
and produce
lesions or pocks. The york sac and
the embryo can arso be used to grow
viruses.
2' Tissue cultures-cell cultures are todayt
the method of choice for propagation of
viruses for
many reasons' Among thenr are convenience,
relative economy for maintenance compared
to
animals' observable cytopiathic effects
and the choice of cells for their susceptibility
to
particular viruses' on the basis of
their origin and characteristics, cell cultures
are
of
three
types: primary cell culture, cliploid cell strains
and continuous cell lines. primary cell
cultures are
derived from normal tissue of an animal.
Unfortunately such type of cells can
be subcultured
only limited number of times.
Diploid cell strains (with normal diploid karyotype)
are derived from primary cell
cultures established from a particular type
of tissue, such as lung or kidney which is of
embryonic origin' They are :;ingle cell type
and can undergo 50 to 100 divisiond before
dying.
such diploid cell strains are host of choice
for many viral studies especially in the production
of
human vaccine viruses' Thel salk poliomyelitis
vaccine was developed after basic research
showing that poliovirus would grow satisfactorily
on monkey
kidney cell cultures.
'
continuous cell lines iappear to be capable of
infinite number of doublings. such cell line
arises from mutation of a cell strain or form
establishment of cell cultures from malignant
tissue' They have altered kanrotype. Such types
of cells are easy to grow. Because of possession
of malignant properties such cells are not used for
virus production for human vaccines.
continuous cell lines have been extremely useful
in cultivating many viruses previously difficult
or impossible to grow.
3' Animals - Some viruses cannot be cultivated in
cell cultures or in embryonated chicken eggs
and must be propagated in li',ring animals. Mice, guinea
pigs, rabbits and primates are used for
this purpose' Animal inoculation is also a good diagnostic
tool because the animat can show
typical disease symptoms and histological tissue
sections of infected tissue can be examined
microscopica lly.
Q4 c' Discuss classification of animal virus on the basis of their
transcription process (g Marks)
Animal viruses are classified on the basis of their transcription
process into following classes:
1' Viruses containing dsDNA - viral DNA (except for pox
virus) enters nucleus of host cell,
where mRNA is synthesized rivith no intermediate
form. mRNA then passes into cytoplasm.
Protein synthesis and assemblv of virus takes place
in the cytoplasm.
2'Viruses containing ssDNA The single
stranded DNA morecule serves as template
for the
synthesis of a complementary strand of DNA,
resulting in a dsDNA molecute called a replicative
form' whether mRNA is a transcription product
of replicative form or of parental ssDNA is not
known.
-
3' Viruses containing dsDNA (+ and strands) (Reovirus)
- During the uncoating process not all
of the nucleoprotein core is degraded. The viral genome
remains enclosed. 10 mRNA molecules
are transcribed from one strand of dsRNA
and pass into the host cytoplasm. This mRNA
may be
used to produce doubre stranded progeny
RNA or structurar proteins.
4' ssRNA virus containing the (+) strand (Poliovirus)
- Folloeinguncoating in the cytoplasm the
parental (+) strand of RNA acts as a mRNA
and directs the synthesis of viral proteins. one
protein is RNA polymerase that catalyzes the
formation of a (-) RNA strand called replicative
intermediate (Rl)' The Rl is a partial dsRNA since
there is complete (-) ssRNA molecute to which
are attached partially synthesized (+) RNA strands. From
Rt a complete dsRNA molecule
(replicative form) will be produced, consisting
of one (+) and one (-) strand. The other(+) RNA
strands were part of Rr may become genomes for
new virus or they act as mRNA.
5'
ssRNA viruses containing
the (-) strand (rhabdovirus, paramyxovirus, orthomyxovirus)
-
Following the uncoating in the cytoplasm the (-) RNa
strand remains associated with an RNA
transcriptase, which catalyzes the synthesis of mRNA
from the (-) RNA parental strand. The
mRNAs code for structural proteins as well as polymerase
and transcriptase. The transcriptase
also catalyzes the synthesis of a (+) RNA strand. From
the (+) strand more (-) RNA molecules will
be transcribed which can act as mRNA o0r genome
for future virus progeny.
6' RNA tumor viruses requiring a DNA intermediate for replication
- Following uncoating, viral
reverse transcriptase ( RNA dependent DNA polymerase)
uses the RNA genome as a template
to transcribe a complimentary DNA strand resulting in the formation
of a DNA-RNA hybrid.
From the DNA strand of the hybrid a complementary DNA
strand is synthesized using a
conventional DNA polymerase enzyme and dsDNA molecule
called as provirus is formed. The
provirus is integrated into the genome of the host.
Q4 d. Elaborate on classification & types based on morphology of Bacteria (7
marks)
Bacteria can be classified on the basis of their morphology. Morphology
refers to their size
shape and arrangement.
,
Most bacteria are 0.2 um in diameter and 2-g um in length.
The three basic bacterial shapes are coccus (spherical),
bacillus (rod-shaped), and spiral (twisted
or curved), however pleomorphic bacteria can assume several shapes.
Arrangement of cocci - cocci may
be oval, elongated, or flattened
on one side. cocci that
remain in pairs after dividing are
called diplococci. cocci that remain
in chains after dividing are
called streptococci' cocci that divide
in two planes and remain in groups
of four are cared
tetrads' cocci that divide in three planes
and remain in groups cube rike groups
of eight are
called sarcinae' cocci that divide in
multiple planes and form grape like
clusters or sheets are
called staphylococci. (Diagram expected)
e. Micrococcus, streptococcus
etc
Bacilli - Most bacilli appear as single
rods (e.g Bacillus, Lactobaciilus).
Diprobaciili appear in pairs
after division' Streptobacilli appear
in chains after division. some bacilli
are so short and fat that
they look like cocci and are referred
to as coccobaciti (e.g. E.coti)(Diagram
expected)
spiral bacteria - spiral bacteria have one
or more twists. Vibrios look like curued
rods. spirilla
have a helical shape and fairly rigid
bodies. spirochetes have a helical shape
and flexible bodies.
spirochetes move by means of axial
filaments, which look like flagella
contained beneath a
flexible external sheath.
ln addition to to the common bacterial
shapes, many others also occur like pear
shaped
(e'g' Pasteuna), lobed spheres (e.g. sutfotobus),
discs arranged like stacks of coins
Caryophanom), star shaped bacteria (e.g.
Ste//o) etc.
cells
(e.g.
Q5. Write a short notes on: (any 3 5 marks
each
)
a. General characters ofArthropoda: (
any5 characters)
1' Body bilaterally symmetrical and matamerically
segmented i.e. the segments usualygroups
in
two or three rather distinct regions.
2.
3.
4.
).
6.
t
i:f"Tffi1nu|H::gh
led with haemolymph or
either bodv surfac. ot
blood.
structure.
gitt, io uquuti. forms and rrachea &
spiraclesin
8' Excretion takes place by.means-of Malpighian
tubules that empty into the alimentarycanal,
the
excreted materials passing to the outsid"
by *uy of tne anus.
9. The sexes nearly always separate.
10' A tubular alimentary canal with anterior
mouth and posterior anus always present.
b.
i)
il)
Economic importance of
fungi ( any 5 relevant points)
Fungi are used u.r p9d. e.g.
Mushrooms and Morels.
Fungi are used in luborutJrv.^""--""'
cerevisae;
beverages such as,win":
beer, rum all are prepared
fe
by
Ihi*"(S. 
