12th NEET

ROI Milestone Test-07 Phase-2

DURATION: 200 Minutes DATE: 08/12/2024 M.MARKS: 720

ANSWER KEY
(PHYSICS)
SECTION-A
1. (3) 8. (4) 15. (3) 22. (4) 29. (1)
2. (3) 9. (3) 16. (2) 23. (4) 30. (1)
3. (3) 10. (2) 17. (1) 24. (3) 31. (1)
4. (4) 11. (2) 18. (3) 25. (2) 32. (3)
5. (2) 12. (3) 19. (3) 26. (3) 33. (1)
6. (4) 13. (3) 20. (2) 27. (1) 34. (1)
7. (2) 14. (2) 21. (2) 28. (1) 35. (2)
SECTION-B
36. (2) 39. (3) 42. (3) 45. (4) 48. (3)
37. (3) 40. (1) 43. (2) 46. (2) 49. (1)
38. (2) 41. (1) 44. (2) 47. (3) 50. (1)
(CHEMISTRY)
SECTION-A
51. (4) 58. (3) 65. (3) 72. (2) 79. (4)
52. (3) 59. (1) 66. (3) 73. (4) 80. (4)
53. (3) 60. (1) 67. (3) 74. (1) 81. (1)
54. (2) 61. (3) 68. (3) 75. (3) 82. (1)
55. (3) 62. (2) 69. (2) 76. (3) 83. (4)
56. (3) 63. (2) 70. (2) 77. (1) 84. (1)
57. (2) 64. (4) 71. (1) 78. (1) 85. (4)
SECTION-B
86. (4) 89. (4) 92. (3) 95. (3) 98. (1)
87. (4) 90. (3) 93. (1) 96. (3) 99. (3)
88. (4) 91. (1) 94. (3) 97. (1) 100. (1)
(BOTANY)
SECTION-A
101. (2) 108. (4) 115. (1) 122. (4) 129. (3)
102. (2) 109. (2) 116. (1) 123. (2) 130. (3)
103. (2) 110. (3) 117. (3) 124. (2) 131. (4)
104. (2) 111. (1) 118. (2) 125. (2) 132. (3)
105. (3) 112. (3) 119. (1) 126. (2) 133. (3)
106. (4) 113. (2) 120. (1) 127. (2) 134. (1)
107. (2) 114. (1) 121. (1) 128. (4) 135. (2)
SECTION-B
136. (2) 139. (1) 142. (2) 145. (1) 148. (4)
137. (1) 140. (2) 143. (3) 146. (4) 149. (2)
138. (2) 141. (3) 144. (4) 147. (2) 150. (1)
(ZOOLOGY)
SECTION-A
151. (1) 158. (4) 165. (2) 172. (3) 179. (2)
152. (3) 159. (3) 166. (2) 173. (2) 180. (1)
153. (4) 160. (4) 167. (2) 174. (1) 181. (3)
154. (3) 161. (3) 168. (3) 175. (1) 182. (4)
155. (2) 162. (1) 169. (2) 176. (1) 183. (4)
156. (1) 163. (3) 170. (1) 177. (3) 184. (3)
157. (4) 164. (1) 171. (4) 178. (1) 185. (3)
SECTION-B
186. (3) 189. (4) 192. (1) 195. (4) 198. (3)
187. (2) 190. (4) 193. (1) 196. (1) 199. (2)
188. (1) 191. (3) 194. (3) 197. (1) 200. (4)
 Hints & Solutions
[MS-7 | 8-Dec-2024 | ROI | 12th | Ph-2]

(PHYSICS)
SECTION-A 8. (4)
Conditions for constructive interference
1. (3)
(Maxima):
• At polarizing angle, refracted light is partially
Phase difference = 2nπ
polarized and reflected light is fully polarised.
Path difference = nλ
• Reflected and refracted rays are perpendicular
to each other. Where n = 0, 1, 2, ...
Conditions for destructive interference (Minima):
2. (3) Phase difference = (2n – 1)π
λD λ
β= Phath difference = (2n – 1)
d 2
λ × (D /2) λD β Where n = 1, 2, 3, ...
β=' = =
2d 4d 4
9. (3)
hc
3. (3) Eg ≤
All colours of white light have zero path λ
difference at C, so all colours will form maxima at hc
λ≤
C. When they combine, a bright white spot is Eg
formed.
hc 12400
⇒ λ max
= ≈ Å ≈ 6200 Å
4. (4) Eg 2
h
λp =
2m p k p 10. (2)
If P side is at higher potential than n side of ρ – n
h
λα = junction, then diode is not in reversed biased
2mα kα condition.
Given kp = kα In option 2, P side potential (–1V) is higher than n
λp mα side potential (–3V).
= = 2
λα mp
11. (2)
λp = 2λα Angular momentum of electron is integral
h
5. (2) multiple of .
2π
13.6
En = − eV nh
n2 L=
2π
for 2nd excited state, n = 3
h
13.6 for n = 2, L =
E3 = − 2 eV π
(3) 2h
= –1.51 eV for n = 4, L =
π
P.E = –2 E3 = –3.02 eV
5h
for n = 10, L =
6. (4) π
Maximum KE of electron = Energy of incident
radiation – Work function of metal. 12. (3)
Kmax = 3.4 – 2.7 = 0.7 eV The mass of the nuclei obtained by fission is less
All other values of KE should be less than or than the mass of the disintegrated nucleus and lost
equal to its maximum value. mass reappears in the form of energy. The total
binding energy of the fission fragments is larger
7. (2) than the total binding energy of the parent
2E nucleus, because fission occurs when total mass
Momentum transferred = F ∆t = energy decreases.
C
13. (3) 18. (3)
1 φ =hv0
R = R0 A3
φ
1 v0 =
h
=
RAl R=
0 (27)
3 3R0 ... (i)
φ
1 = 1 × 1014 s–1
=RTe R= (125) 3 5 R0 ... (ii) h
0
RTe 5 R0
= 19. (3)
RAl 3R0
 1 1 1.5
5 13.6 1 − 2  = 12.1 ⇒ 2 =
RTe = RAl  n  n 13.6
3
⇒n=3
14. (2) n ( n − 1)
∴ Number of spectral lines = =3
e 2
i=
T
1 20. (2)
T=
f In YDSE, all bright and dark fringes are of equal
f ∝ω width.
v
ωn =n 21. (2)
rn All statements are correct.
Z2
ωn ∝
n3 22. (4)

n3 Z2 13.6Z 2
so, T ∝ , hence i ∝ E= −
Z2 n3 n2
for Beryllium, Z = 4
i1 (3)2 (2)3 8
= × = −13.6 × (4) 2
i2 (1)3 (3)2 1 =E1 = –217.6 eV
12
15. (3)
A full-wave rectifier rectifies both the half cycles 23. (4)
of the AC output i.e. it conducts twice during a Z2
cycle. E = −13.6 eV
n2
So, frequency of AC output = 2 × frequency of
AC input −13.6(3) 2
E1 = = −122.4 eV
= 2 × 50 = 100 Hz. (1) 2
16. (2) Ionization energy of an electron = + 122.4 eV
+ − −
α β
290
82 X  → 80
286
Y 
e
→ 79
286
Z  → 80
286
P 
e
→ 81
286
Q 24. (3)
For α emission, mass number decreases by 4 and Rutherford nuclear model has two main
atomic number decreases by 2. difficulties in explaining the structure of atom:
For e+, atomic number decreases by 1 and mass (a) It predicts that atoms are unstable because
number remains unchanged.
the accelerated electrons revolving around
For β–, mass number is unchanged and atomic
the nucleus must spiral into the nucleus. This
number increases by 1.
contradicts the stability of matter.
For e-, atomic number increases by 1 and mass
number remains unchanged. (b) It cannot explain the characteristic line
spectra of atoms of different elements.
17. (1)
The V-I characteristic is for a solar cell 25. (2)
• If any key from A and B is closed (on
condition), bulb will blow.
• If both keys are closed (on condition), bulb
will not glow.
• If both keys are open (off condition), bulb
will glow.
 26. (3) 34. (1)
12.27 nh
λ= Å mvr =
V 2π
V = 36 − 20 = 16 volt v=
nh
12.27 2π mr
λ=
16 h h × 2π mr
=
λ =
= 3.1Å mv mnh
2πr
27. (1) λ=
n
∆V
Dynamic resistance =
∆I 35. (2)
0.9 − 0.8 0.1 On increasing frequency, the stopping potential
=Rd =
( 30 − 25) × 10 −3
5 × 10−3 increases v3 > v2 > v1.
= 20 Ω SECTION-B

28. (1) 36. (2)

The nuclear force is charge independent and is
attractive at this separation. However, two protons
exert Coulomb repulsion on each other, which is
weaker than the nuclear force.

29. (1)
Width of depletion region increases on application Y = A. B + A = A.( B + 1) = A.1= A
of reverse bias.
37. (3)
30. (1)
n
=
µ tan θ= 3 p =   hv
B t
θ B = 60°
 n  hc
using Snell’s law p= 
t λ
1 × sin 60° = 3 sin r
n pλ 60 × 10−3 × 6000 × 10−10
3 = = = 1.8 × 1017
= 3 sin r t hc (6.626 × 10−34 ) × 3 × 108
2
1
sin r = 38. (2)
2 ( K .E ) max =q∆V =e( Ed )
r = 30°
= e(4 × 1)
31. (1) = 4 eV
Statement I is correct and II is incorrect. 1240
Energy of incident photon = = 6.2 eV
Atoms are electrically neutral as they have equal 200
number of positive and negative charges. Also, φ = 6.2 – 4 = 2.2 eV
atoms of most elements are stable and they emit
characteristics spectrum of their own. 39. (3)
32. (3) BE = ( 2m p )
+ 2mn − mnucleus × 931.5
BE = ( 2 × 1.0073 + 2 × 1.0087 − 4.0015) × 931.5
= 931.5 × 0.0305 = 28.4 MeV
1
% of incident light passing = × 100 =
12.5% 40. (1)
8
2λ
33. (1) Angular width of central maxima =
a
For no change in position of central maxima
2 × 6328 × 10−10
(µ1 – 1) t1 = (µ2 – 1) t2 θ=
1 3 0.2 × 10−3
  (1.2) =   (t2 ) = 6.328 × 10−3 radian
2 2
1.2 6.328 × 10−3 × 180°
=
t2 = 0.4 µm = = 0.36°
3 π
41. (1) 46. (2)
mv
R= RX (8)1/3
qB = = (2)1/3
RY (4)1/3
qBR
v= The stability of an element depends upon the
m
h h h h binding energy per nucleon.
λ= = = =
P mv mqBR qBR
m 47. (3)
42. (3) ni=
2
ne × nh
 1 1 
1
= R 2 − 2  n=
i 1.5 × 10
16

λ  n f ni 
  n=
h 4.5 × 10
22
For longest wavelength, ni = 2, n f = 1
ni2
1  1 1  3R ne =
= R 2 − 2  = nh
λ1 1 2  4
For shortest wavelength, ni = ∞, n f = 1 ne = 5 × 109 m −3
1 1 1 
= R 2 − 2  = R
λ2 1 ∞  48. (3)
λ1 R α air λ air 0.2 × 3
= =
αw = = 0.15°
λ2 3 R µ.λ air 4
4
4
= 49. (1)
3
At distance of closest approach, kinetic energy of
43. (2) the particle will be completely converted into
electrostatic potential energy.
1 2 K (2e)( Ze)
mv =
2 d min

(2 KZe 2 ) × 2
d min =
mv 2
Potential through zener diode is maintained at 15 V.
15 4KZe 2
Current through 1000 Ω = = 0.015 A =
1000 mv 2
20 − 15 1
Current through =250Ω = = 0.02 A
250 50 50. (1)
∴ Current through diode = 0.02 – 0.015 = 0.005 A 1 1 1
= R − 
λ 4 9
44. (2)
φ 1 5
Resultant intensity I = I 0 cos 2   =R
2 λ 36
2π 2π λ λ=
36
∆φ
= . ∆=
x × = π
λ λ 2 5R
π 1  7 
= R
Now, I = I 0 cos 2  
2 λ′ 16 × 9 
I=0 16 × 9
λ′ =
7R
45. (4)
λ′ 16 × 9  5 R 
2
1H +12 H →24 He + E =  
λ 7 R  36 
(B.E)reactant = 2 (1.1 + 1.1) = 4.4 MeV
(B.E)product = 4 × 7 = 28 MeV 20
λ′
= λ
E = 28 – 4.4 = 23. 6 MeV 7
 [MS-7 | 8-Dec-2024 | ROI | 12th | Ph-2]

(CHEMISTRY)
SECTION-A 61. (3)
51. (4) (A) Hypophosphorous acid (IV) H3PO2
CO2 is evolved with effervescence. (B) Orthophosphorous acid (II) H3PO3
(C) Pyrophosphorous acid (III) H4P2O5
52. (3)
(D) Pyrophosphoric acid (I) H4P2O7
H2S smells like rotten eggs.

62. (2)
53. (3)
6FeSO4 + 3H2SO4 + 2HNO3 → 3Fe2(SO4)3
+4H2O + 2NO
[Fe(H 2 O)6 ]SO 4 + NO → [Fe(H 2 O)5 NO]SO4 + H 2 O
Brown

54. (2) 63. (2)

Bond dissociation enthalpies Fe(OH)3 + 3HCl → FeCl3 + 3H2O
Cl2 > Br2 > F2 > I2 4FeCl3 + 3K4[Fe(CN)6] → Fe4 [Fe(CN)6 ]3 + 12KCl
Prussian Blue

55. (3)
Chlorine is a greenish yellow coloured gas. 64. (4)
Bromine and iodine are only sparingly soluble in Egg albumin is a Lyophilic sol which is reversible
water. and is used as protective sol.

56. (3) 65. (3)

Both O2 & Xe have almost same ionization Lowest O.N. ⇒ Ag (+1)
enthalpy.
Highest O.N. ⇒ Mn (+7)

57. (2)
66. (3)
The general electronic configuration of group 16
elements is ns2np4. =µ n(n + 2) B.M.
where n = number of unpaired e–.
58. (3) Both Mn2+ and Fe3+ have 5 unpaired e–.
Zn, Cd and Hg are the elements of group 12 and
show (n − 1)d10 ns 2 electronic configuration. 67. (3)
H2S is less acidic than H2Te because the bond
59. (1) dissociation enthalpy (E-H) decreases as we move
The fusion of MnO2 with an alkali metal hydroxide down the group and hence the acidic character
and an oxidizing agent like KNO3 will produce the increases.
dark green K2MnO4 which disproportionates in a
neutral or acidic solution to give permanganate.
68. (3)
2MnO 2 + 4KOH + O 2 → 2K 2 MnO 4 + 2H 2 O
H2O has maximum boiling point because it
3MnO 24 − + 4H +
→ 2MnO 4− + MnO 2 + 2H 2 O exhibits hydrogen bonding. On moving down the
group size of atom increases and hence magnitude
60. (1) of Van der Waals force increases. Therefore, the
pH =8(basic) correct of boiling point is H2S < H2Se < H2Te <
Cr2 O72 − 
 2−
 CrO 4
pH = 6 (acidic) H2O.
Orange Yellow
69. (2)
Red phosphorus is polymeric in nature consisting
(2) H3PO3 →
of chain of P4 tetrahedral linked together.

(3) H3PO2 →

70. (2)
H+
MnO 4− + I − 
→ I2 (4) H3PO4 →
−
MnO 4− + I − 
OH
→ IO3–

71. (1) 77. (1)

K2Cr2O7 + H2SO4 + 4H2O2 → 2CrO5 + K 2SO4 + 5H 2O SF4 is a gas.
Blue

72. (2) 78. (1)

Cr2 O72 − + 3SO32 − + 8H + → 2Cr 3+ + 3SO 42 − + 4H 2 O , Halogen have very high ionisation enthalpy.

Nitrate ion, Ferric ion, Sulphate ion are already in

their highest oxidation state thus they cannot be 79. (4)
further oxidized. The order will be:

73. (4)
Lu 3+ < Eu 3+ < La 3+
Aniline does not undergo this reaction because the
reagent FeCl3 (the lewis acid which is used as a 80. (4)
catalyst), being electron deficient acts as a lewis (1) Brass – Cu + Zn
acid and attacks on the lone pair of nitrogen
(2) Bronze – Cu + Sn
present in aniline to form an insoluble complex
which precipitates out and the reaction does not (3) Stainless steel – Cr + Ni + Fe
proceed.
81. (1)
74. (1)
→ LnX3 ,(Ln +3 & X − )
with halogens
Ln 
• In the titration of HCl against NaOH,
phenolphthalein is used as a suitable indicator.
• Phenolphthalein is pink coloured in basic 82. (1)
medium. Misch alloy – Lanthanoid metal (95%) + Iron (5%)

75. (3)
83. (4)
Lassaigne’s test for the detection of nitrogen will
fail in the case of NH 2 — NH 2 . Lawrencium is a man made element so it is not
found in nature.

76. (3)
Reducing properties ∝ no. of P — H bonds. 84. (1)
Acetic acid, CH3COOH would not respond to
idoform test. In the mechanism of haloform
(1) H4P2O7 →
reaction, in the first step, base deprotonates most
acidic alpha H atom (of methyl keto group).
 In acetic acid, the most acidic proton is attached to 92. (3)
O atom. So deprotonation of α-hydrogen does not Inert gases have low melting & boiling point due
occur and hence no haloform reaction. to weak dispersion forces.

85. (4) 93. (1)

The compound given below is named as Aniline XeF4 + SbF5 → [XeF3 ]+ [SbF6 ]−
yellow.

SECTION-B 94. (3)

86. (4) White phosphorus is insoluble in water, soluble in

CS2 and a translucent white waxy solid.
Hypophosphoric acid – H4P2O6
O O
  95. (3)
HO —P — P — OH • Mohr’s salt is a double salt.
 
OH OH • Mohr’s salt contains 6 molecules of water.
Basicity = 4
96. (3)

87. (4) Record the time immediately after the appearance

of blue colour.
873 K, 7 bar
Xe(g) + 2F2 (g) → XeF4 (s)
(1: 5 ratio)
97. (1)
Tollen’s reagent gives a positive test with all
88. (4) aldehydes. Tollen’s reagent oxidizes an aldehyde
A. V2O5 is used in contact process. into the corresponding carboxylic acid. Fehling’s
test is known to be not specific for aldehydes.
B. TiCl4 + Al(CH3)3 is used in polymerization of
ethylene.
98. (1)
C. Nickel complexes are useful in polymerization
of alkynes. A member of the lanthanoid series which is well
known to exhibit +4 oxidation state is Cerium
(Z = 58).
89. (4)
Statements 1, 2 and 3 are related to lanthanoid 99. (3)
contraction. • Elements of Group 16 generally show lower
value of first ionization enthalpy compared to
90. (3) the corresponding elements of group 15.

• The actinoids show in general +3 oxidation • Due to extra stable half-filled p orbitals
electronic configuration of Group 15
state.
elements, larger amount of energy is required
• Actinoid contraction is greater from element to remove electrons as compared to Group 16
to element than lanthanoid contraction. elements.

91. (1) 100. (1)

More no. of O.S. are exhibited by the actinoids (A) Sc3+ (II) Colourless
than by the lanthanoids because there is lesser (B) Cr3+ (IV) Violet
2+
energy difference between 5f & 6d orbitals than (C) Fe (I) Green
between 4f & 5d orbitals. (D) Mn2+ (III) Pink
 [MS-7 | 8-Dec-2024 | ROI | 12th | Ph-2]
(BOTANY)
SECTION-A 109. (2)
Waking up to a bulbul’s song in the morning,
101. (2)
pollination and oxygen are broadly utilitarian
Some organisms breed only once in their lifetime
arguments for conserving biodiversity
(Pacific salmon fish, bamboo) while others breed
many times during their lifetime (most birds and
110. (3)
mammals). Some produce a large number of
Forest, grassland and desert are some examples of
small-sized offspring (Oysters, pelagic fishes)
terrestrial ecosystems; pond, lake, wetland, river
while others produce a small number of large
and estuary are some examples of aquatic
sized offspring (birds, mammals).
ecosystems. Crop fields and an aquarium may
also be considered as man-made ecosystems.
102. (2)
Birth rate, death rate and sex ratio are the
111. (1)
characteristics of a population.
Vertical distribution of different species
occupying different levels is called stratification.
103. (2)
The malarial parasite needs a vector (mosquito) to
112. (3)
spread to other hosts.
Evolutionary changes through natural selection
take place at the population level and hence,
104. (2) population ecology is an important area of
A population growing in a habitat with limited ecology.
resources show initially a lag phase, followed by
phases of acceleration and deceleration and finally 113. (2)
an asymptote, when the population density According to the International Union for
reaches the carrying capacity. Conservation of Nature and Natural Resources
(IUCN) (2004), the total number of plant and
105. (3) animal species described so far is slightly more
The consumers that feed on these herbivores are than 1.5 million.
carnivores, or more correctly primary carnivores
(though secondary consumers). Those animals 114. (1)
that depend on the primary carnivores for food are Ex situ Conservation– In this approach, threatened
labelled secondary carnivores. animals and plants are taken out from their natural
habitat and placed in special setting where they
106. (4) can be protected and given special care.
Steps involved in decomposition of detritus are Zoological parks, botanical gardens and wildlife
fragmentation, leaching, catabolism, humification safari parks serve this purpose.
and mineralization.
115. (1)
107. (2) In the rivet popper hypothesis, airplane was
Many species extinctions in the last 500 years equivalent to ecosystem.
(Steller’s sea cow, passenger pigeon) were due to
overexploitation by humans. 116. (1)
Net primary productivity is the available biomass
108. (4) for the consumption to heterotrophs (herbiviores
Sacred groves are found in Khasi and Jaintia Hills and decomposers). Secondary productivity is
in Meghalaya, Aravalli Hills of Rajasthan, defined as the rate of formation of new organic
Western Ghat regions of Karnataka and matter by consumers. Gross primary productivity
Maharashtra and the Sarguja, Chanda and Bastar of an ecosystem is the rate of production of
areas of Madhya Pradesh. organic matter during photosynthesis.
117. (3) 126. (2)
A constant input of solar energy is the basic The detritus food chain (DFC) begins with dead
requirement for any ecosystem to function and organic matter. It is made up of decomposers
sustain. Primary productivity depends on the plant which are heterotrophic organisms, mainly fungi
species inhabiting a particular area. It also and bacteria.
depends on a variety of environmental factors,
availability of nutrients and photosynthetic 127. (2)
capacity of plants. India now has 14 biosphere reserves, 90 national
parks and 448 wildlife sanctuaries.
118. (2)
The components of the ecosystem are seen to 128. (4)
function as a unit when we consider the following There are four major causes of biodiversity loss:
aspects: (i) Productivity; (ii) Decomposition; (iii) habitat loss and fragmentation, Over-exploitation,
Energy flow; and (iv) Nutrient cycling. co-extinctions and alien species invasions.

119. (1) 129. (3)

The Calotropis plant produces highly poisonous The interactions that are examples of mutualism
cardiac glycosides and that is why cattle and goats are: lichens, orchid flower and bee, and fig and
have never been seen to browse on Calotropis. wasp.

120. (1) 130. (3)

Verhulst-Pearl Logistic Growth equation is; The size of the population tells us a lot about its
K–N status in the habitat. The size of a population for
dN/dt = rN   Where N = Population any species is not a static parameter. It keeps
 K  changing with time, depending on various factors
density at time t, r = Intrinsic rate of natural including food availability, predation pressure and
increase, K = Carrying capacity adverse weather.
121. (1)
131. (4)
Gause and other experimental ecologists did,
The Mediterranean orchid Ophrys employs
when resources are limited the competitively
‘sexual deceit’ to get pollination done by a species
superior species will eventually eliminate the
of bee.
other species, but evidence for such competitive
exclusion occurring in nature is not always
132. (3)
conclusive.
Gross primary productivity minus respiration
losses (R), is the net primary productivity (NPP).
122. (4)
GPP – R = NPP
Predation Plants and herbivores
Competition Barnacle Balanus and barnacle
133. (3)
Chathamalus
Among animals, insects are the most species-rich
Parasitism Ticks on dogs taxonomic group, making up more than 70 per
Mutualism Lichens cent of the total.
123. (2) 134. (1)
When we conserve and protect the whole
ecosystem, its biodiversity at all levels is
protected - we save the entire forest to save the
tiger. This approach is called in situ (on site)
Stable conservation. However, when there are situations
where an animal or plant is endangered or
threatened (organisms facing a very high risk of
124. (2)
extinction in the wild in the near future) and needs
Of the incident solar radiation less than 50 per urgent measures to save it from extinction, ex situ
cent of it is photosynthetically active radiation (off site) conservation is the desirable approach.
(PAR).
135. (2)
125. (2) The historic Convention on Biological Diversity
Producer 10,000J (‘The Earth Summit’) held in Rio de Janeiro in
Primary consumer 1000 J 1992, called upon all nations to take appropriate
Secondary consumer 100J measures for conservation of biodiversity and
Tertiary consumer 10 J sustainable utilisation of its benefits.
 SECTION B 144. (4)
On a logarithmic scale, the species area
136. (2)
relationship is a straight line described by the
The Monarch butterfly is highly distasteful to its
equation log S = log C + Z log A.
predator (bird) because of a special chemical
present in its body. Interestingly, the butterfly
145. (1)
acquires this chemical during its caterpillar stage
Animals that try to steal nectar without aiding in
by feeding on a poisonous weed.
pollination are considered cheaters in case of
pollination.
137. (1)
The density of a population in a given habitat
146. (4)
during a given period, fluctuates due to changes in
Immigration is the number of individuals of the
four basic processes, two of which (natality and
same species that have come into the habitat from
immigration) contribute to an increase in
elsewhere during the time period under
population density and two (mortality and
consideration. Emigration is the number of
emigration) to a decrease.
individuals of the population who left the habitat
and gone elsewhere during the time period under
138. (2)
consideration.
Brood parasitism in birds is a fascinating example
of parasitism in which the parasitic bird(cuckoo)
147. (2)
lays its eggs in the nest of its host(crow) and lets
Dodo Mauritius
the host incubate them.
Quagga Africa
Thylacine Australia
139. (1)
Steller’s Sea Cow Russia
A population growing in a habitat with limited
resources show initially a lag phase, followed by
148. (4)
phases of acceleration and deceleration and finally
Speciation is generally a function of time, unlike
an asymptote, when the population density
temperate regions subjected to frequent
reaches the carrying capacity.
glaciations in the past, tropical latitudes have
remained relatively undisturbed for millions of
140. (2)
years and thus, had a long evolutionary time for
Species-Area relationships was given by
species diversification, (b) Tropical environments,
Alexander von Humboldt.
unlike temperate ones, are less seasonal, relatively
more constant and predictable. There is more
141. (3)
solar energy available in the tropics, which
Plants capture only 2-10 per cent of the PAR and
contributes to higher productivity.
this small amount of energy sustains the entire
living world.
149. (2)
If 4 individuals in a laboratory population of 40
142. (2)
fruitflies died during a specified time interval, say
In an aquatic ecosystem, GFC is the major conduit
a week, the death rate in the population during
for energy flow.
that period is 4/40 = 0.1 individuals per fruitfly
per week.
143. (3)
150. (1)
In most ecosystems, all the pyramids, of number,
of energy and biomass are upright, i.e., producers
are more in number and biomass than the
herbivores, and herbivores are more in number
and biomass than the carnivores.
 [MS-7 | 8-Dec-2024 | ROI | 12th | Ph-2]

(ZOO(ZOOLOGY)LOGY)
SECTION-A 157. (4)
151. (1) In 1983, Eli Lilly an American company prepared
Cohen had developed a method of removing these two DNA sequences corresponding to A and B,
plasmids from the cell and then reinserting them in chains of human insulin and introduced them in
other cells. Combining this process with that of plasmids of E. coli to produce insulin chains.
DNA splicing enabled Boyer and Cohen to
recombine segments of DNA in desired 158. (4)
configurations and insert the DNA in bacterial
Transgenic animal Animals having foreign in it
cells, which could then act as manufacturing plants
for specific proteins. ELISA Based on the principle of
antigen-antibody reaction
152. (3) Probe Radioactive molecule
The Green Revolution succeeded in tripling the PCR Polymerase chain reaction
food supply but yet it was not enough to feed the
growing human population. Increased yields have 159. (3)
partly been due to the use of improved crop
Insulin consists of two short polypeptide chains:
varieties, but mainly due to the use of better
management practices and use of agrochemicals chain A and chain B, that are linked together by
(fertilisers and pesticides). However, further disulphide bridges.
increases in yield with existing varieties are not
possible using conventional breeding. 160. (4)
Transformation is a procedure through which a
153. (4) piece of DNA is introduced in a host bacterium.
Many processes/techniques are also included under
biotechnology. For example, in vitro fertilisation
161. (3)
leading to a ‘test-tube’ baby, synthesising a gene
and using it, developing a DNA vaccine or Biopiracy is the term used to refer to the use of bio-
correcting a defective gene, are all part of resources by multinational companies and other
biotechnology. organisations without proper authorisation from
the countries and people concerned without
154. (3) compensatory payment.
Any part of a plant taken out and grown in a test
tube, under sterile conditions in special nutrient
162. (1)
media is called explant.
Traditional hybridisation procedures used in plant
155. (2) and animal breeding, very often lead to inclusion
Restriction endonucleases are used in genetic and multiplication of undesirable genes along with
engineering to form ‘recombinant’ molecules of the desired genes. The techniques of genetic
DNA, which are composed of DNA from different engineering overcome this limitation and allows us
sources/genomes. When cut by the same restriction to isolate and introduce only one or a set of
enzyme, the resultant DNA fragments have the desirable genes without introducing undesirable
same kind of ‘sticky-ends’ and, these can be joined
genes into the target organism.
together (end-to-end) using DNA ligases.

156. (1) 163. (3)

Maintenance of sterile (microbial contamination- Biotechnology deals with techniques of using live
free) ambience in chemical engineering processes organisms or enzymes from organisms to produce
to enable growth of only the desired products and processes useful to humans. The EFB
microbe/eukaryotic cell in large quantities for the has given a definition of biotechnology that
manufacture of biotechnological products like encompasses both traditional view and modern
antibiotics, vaccines, enzymes, etc is called
molecular biotechnology.
bioprocess engineering.
164. (1) 173. (2)
In mammals, including humans, insulin is The Bt toxin protein exist as inactive protoxins but
synthesised as a pro-hormone (like a pro-enzyme, once an insect ingest the inactive toxin, it is
the pro-hormone also needs to be processed before converted into an active form of toxin due to the
it becomes a fully mature and functional hormone) alkaline pH of the gut which solubilise the crystals.
which contains an extra stretch called the C The activated toxin binds to the surface of midgut
peptide. This C peptide is not present in the mature epithelial cells and create pores that cause cell
insulin and is removed during maturation into swelling and lysis and eventually cause death of the
insulin. insect.

165. (2) 174. (1)

TetR Restriction site for BamH I The Green Revolution succeeded in tripling the
AmpR Restriction site for Pst I food supply but yet it was not enough to feed the
growing human population. Increased yields have
rop Restriction site for Pvu II
partly been due to the use of improved crop
Sticky end Has over hanging streches
varieties, but mainly due to the use of better
management practices and use of agrochemicals.
166. (2)
Ori is a sequence from where replication starts and
175. (1)
any piece of DNA when linked to this sequence can Method of producing thousands of plants through
be made to replicate within the host cells. tissue culture is called micro-propagation. Each of
these plants will be genetically identical to the
167. (2) original plant from which they were grown, i.e.,
The Bt toxin is coded by a gene named cry. There they are somaclones.
are a number of them, for example, the proteins
encoded by the genes cryIAc and cryIIAb control 176. (1)
the cotton bollworms, that of cryIAb controls corn Gene therapy is a method that allows correction of
borer. a gene defect that has been diagnosed in a
child/embryo.
168. (3) Correction of a genetic defect involves delivery of
B. thuringiensis forms protein crystals during a a normal gene into the individual or embryo to take
particular phase of their growth. over the function of and compensate for the non-
functional gene.
169. (2)
EcoRI comes from Escherichia coli RY 13. In 177. (3)
EcoRI, the letter ‘R’ is derived from the name of Ori is a sequence from where replication starts and
strain. Roman numbers following the names any piece of DNA when linked to this sequence can
indicate the order in which the enzymes were be made to replicate within the host cells. This
isolated from that strain of bacteria. sequence is also responsible for controlling the
copy number of the linked DNA.
170. (1)
A vector can have restriction site of many 178. (1)
restriction enzyme. The palindromic sequence for Eco RI is
5' —— GAATTC —— 3'
171. (4) 3' —— CTTAAG —— 5'
A nematode Meloidegyne incognitia infects the
roots of tobacco plants and causes a great reduction 179. (2)
in yield. Thermostable DNA polymerase was isolated from
a bacterium Thermus aquaticus which lives in hot
Sulphur springs.
172. (3)
Genetic modification in plants has reduced reliance
180. (1)
on chemical pesticides.
ADA stands for adenosine deaminase.
181. (3) epithelial cells and create pores that cause cell
EFB stands from European Federation of swelling and lysis and eventually cause death of the
biotechnology. insect.

182. (4) 187. (2)

‘A’ represents flat bladed impeller. In 1997, the first transgenic cow, Rosie, produced
human protein-enriched milk (2.4 grams per litre).
The milk contained the human alpha-lactalbumin
and was nutritionally a more balanced product for
human babies than natural cow-milk.

188. (1)
Golden rice is rich in Vitamin ‘A’.

189. (4)
Treatment of Alpha-antitrypsin
emphysema
183. (4) Pomato Somatic hybrid
The first clinical gene therapy was given in 1990 to RNAi dsRNA is formed
a 4-year old girl with adenosine deaminase (ADA) ADA Bone marrow transplantation
deficiency. This enzyme is crucial for the immune deficiency
system to function.
190. (4)
184. (3) Using Agrobacterium vectors, nematode-specific
RNAi takes place in all eukaryotic organisms as a genes were introduced into the host plant. The
method of cellular defense. This method involves
introduction of DNA was such that it produced
silencing of a specific mRNA due to a
both sense and anti-sense RNA in the host cells.
complementary dsRNA molecule that binds to and
These two RNA’s being complementary to each
prevents translation of the mRNA (silencing).
other formed a double stranded (dsRNA) that
The source of this complementary RNA could be
initiated RNAi and thus, silenced the specific
from an infection by viruses having RNA genomes
or mobile genetic elements (transposons) that mRNA of the nematode.
replicate via an RNA intermediate.
191. (3)
185. (3) Small volume cultures cannot yield appreciable
Polymerase Chain reaction is used in DNA quantities of products. To produce in large
amplification. In this reaction, multiple copies of quantities, the development of bioreactors, where
the gene (or DNA) of interest is synthesised in vitro large volumes (100-1000 litres) of culture can be
using two sets of primers (small chemically processed, was required. Thus, bioreactors can be
synthesised oligonucleotides that are thought of as vessels in which raw materials are
complementary to the regions of DNA) and the biologically converted into specific products,
enzyme DNA polymerase. The ampicillin resistant individual enzymes, etc., using microbial plant,
gene is used as a selectable marker to check animal or human cells.
transformation.
192. (1)
SECTION-B In majority of organisms this is deoxyribonucleic
186. (3)
acid or DNA. In order to cut the DNA with
The Bt toxin protein exist as inactive protoxins but
restriction enzymes, it needs to be in pure form,
once an insect ingests the inactive toxin, it is
free from other macro-molecules. Genes are
converted into an active form of toxin due to the
located on long molecules of DNA interwined with
alkaline pH of the gut which solubilise the crystals.
proteins such as histones.
The activated toxin binds to the surface of midgut
193. (1) 198. (3)
The removal of precipitated DNA after addition of
chilled ethanol is called spooling.

194. (3)
Extension of primer on the template DNA is
catalysed by taq polymerase in a PCR.
‘A’ represents the smallest band of DNA. The
195. (4) smaller is the band the more farther it will run on
Basmati rice is distinct for its unique aroma and the gel electrophoresis from the well.
flavour. 27 documented varieties of Basmati are
199. (2)
grown in India. There is reference to Basmati in
The separated bands of DNA are cut out from the
ancient texts, folklore and poetry, as it has been agarose gel and extracted from the gel piece. This
grown for centuries. step is known as elution. The DNA fragments
purified in this way are used in constructing
196. (1) recombinant DNA by joining them with cloning
Rice is an important food grain, the presence of vectors.
which goes back thousands of years in Asia’s
agricultural history. 200. (4)
Insulin Earlier extracted from
There are an estimated 200,000 varieties of rice in
animals
India alone.
Therapeutic drugs 12 are presently marketed in
India.
197. (1) RNA interference Present in all eukaryotic
A bioreactor provides the optimal conditions for organisms
achieving the desired product by providing Disulphide bond Used in joining A chain and
optimum growth conditions (temperature, pH, B chain
substrate, salts, vitamins, oxygen).

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