Solution-BTS 2
Solution-BTS 2
Date: 02-Apr-2025
Duration: 3 Hours
Physics - Section A
1. 2.
Answer: 1 Answer: 3
Sol: Sol:
ne nh = (ni )
2
Displacement = Area of graph with sign
semi-conductor. = 25 + 50 + 75 + 50 − 50
Here; = 150 m
nh = 10
21
, ne =?, ni = 10
19 Distance → Area of graph with positive value
10
21
× ne = 10
19
× 10
19 Distance = 25 + 50 + 75 + 50 + 50 = 250
Distance 250 5
10
38
17 −3 = =
ne = 21
= 10 m Displacement 150 3
10
3.
Answer: 1
Sol:
Here from the graph we see that both x,y are
at same temperature but they are varying
w.r.t time, so
dT dT
( ) > ( )
dt x dt y
λ =
2π
= 1m By Kepler's third law, T
2
∝ R
3
2π
λ 1 2 3 2 3
T T T2 R2
= m
or
1 1
2 2 ∴ 2
= 3
( ) = ( )
T T T1 R1
2 2
5. 3
2 2 3.5R
⇒ T = T ( )
Answer: 3 2 1 7 R
Sol: (∴ R2 = R + 2. 4 R and R1 = R + 6 R)
2
T
The Magnetic force is given by or T
2
=
1
⇒ T2 =
T1
2 8
2√ 2
F = Bil
24
⇒ T2 =
where l = displacement length 2√2
l = length AB ∴ T2 = 6√2h
8.
2
2
here l = √L + (2r)
2 2 Answer: 4
l = √L + 4r
Sol:
then, force is equal to
2 2
According to given pattern of wave, the
F = Bi√L + 4r
wavelength can be gives as:
6. 3λ
= 6
2
Answer: 3
λ =
12
= 4m .
Sol:
3
ΔV ΔP
(0–1×10 )
5
−7
Sol:
∴ = − = − 11
= 8 × 10
V β
Given,
1.25×10
KAg ⇒ 11Kfe
dQ ΔT
=
dt L
( )
Keq A
100−T T−0
H ⇒ =
L L
K A K A
fe Ag.
km 5
vA = 90 = 90 × = 25 m/s
18
4V02 =
hr 2 2
v + vx
0
Velocity of train B
Vx2 = 3V02
km 5
vB = 54 = 54 × = 15 m/s
hr 18 qE t
0
∴ √3v0 =
m
Velocity of train B w.r.t. train A
√3 mv0
∣
→
∣ ∣
→
∣ t=
= v B − v A qE
∣ ∣ ∣ ∣ 0
13.
= 15 − (−25) m/s = 40 m/s
length of train
Answer: 2
Time of crossing =
relative velocity
Sol:
At depth,
ℓ ′ h d
(8) = g = g(1 − )or g(1 − )
40 R R
g d
ℓ = 8 × 40 = 320 meter ⇒ = g(1 − )
n R
11. n−1
or d = R(
n
)
Answer: 2
Sol: 14.
2Tcosθ Sol:
h =
D
( ) ρg
2
Inet = I1 + I2 + 2√I1 I2 cosϕ ----(1)
Since, we know that height of capillary rise is
Here,
o 1
I1 = I2 = Io andcos 60 =
inversely proportional to radii of tube, i.e., 2
height ∝
1 in equation (1), resultant intensity
radius
1
Inet = Io + Io + (2Io × ) = 3Io
h1 D2 22 2
⇒ = =
h2 D1 66
⇒ Inet = 3Io
⇒ D1 : D2 = 3 : 1
15. 18.
Answer: 3 Answer: 2
Sol: Sol:
→ 2
r = 10t î + 15t ĵ + 7k̂
There is silence at point D, o it is a point of
destructive interference.
→
→ d r
v =
dt
= 10 î + 30 t̂ ĵ For Minima,
→ 1
→ d v Δy = (n − )λ
a = = 30 ĵ 2
dt
1
→ 2ℓ − ℓ = λ
→ 2
F = (m) a = (m)(30 ĵ )
λ = 2ℓ
–15
1.96×10 ×10
Initially and finally
3
E1 = N1 kT1 =
2 (400/0.02)
3
E2 = N2 kT2 –14
2 1.96×10 –18
= 4
= 0. 98 × 10
20×10
But according to proble E1 = E2 and N2 =
2N1 = 9.8×10–19 ≈ 6e
3 3 T1
∴ N1 kT11 = (2N) kT2 ⇒ T2 =
2 2 2
N1 T1 = N2 T2 ∴ NT = constant
–3
= 5 mH
–LΔI eΔt 5×10
e = ∣
∣
∣ ⇒ L = ∣
∣ ∣
∣ =
∣
Δt ΔI 1
20. 23.
Answer: 4 Answer: 2
Sol: Sol:
VP − VQ = 2 V
24.
Answer: 2
For 4 kg block applying second law : Sol:
40 – T = 4a The velocity of sound can be mathematically
expressed as
γP
v = √
d
Fk = 0. 02 × 40 × 10 = 8N
where is γ specific heat ratio, P is the
For 40 kg block applying Newton’s second pressure of gas and d is the density of the
law medium.
T – 8 = 40 a According to this, the velocity of sound in a
Solving above equations
medium is inversely proportional to the
square of the density of that medium,
8 −2
a = ms 1
11 v ∝
√d
21.
So, the velocity will be lower for denser
Answer: 1 medium and higher for rarer medium.
Sol:
Dω = −DU
Dω = −DU = −2J
22.
Answer: 3
Sol:
2
2
Z = √R + (2πvL)
≃ 50 ohm
25. 27.
Answer: 2 Answer: 4
Sol: Sol:
The Einstein's equation for photoelectric
effect is given by,
KEmax = hf − hf0
−
→ and f0 = threshold f requency.
vA = vȷ̂
−
→
Since maximum kinetic energy of photo
vB = −v ı̂ electrons is greater than zero so
4
×
1
v
=
πR
2v
hf − hf0 > 0
28.
Displacement from A to B = R√ 2
Answer: 3
Now, Average velocity from A to B
Displacement
Sol:
R√2 2√2v
= = =
Time πR
2v
π
The electrical potential producd by the
nucleus at the position of the electron,
Instantaneous velocity at B is −v ı̂
q
9
V = 9 × 10 ×
According to question, r
–19
(+1.6×10 )
9
instantaneous velocity π = 9 × 10 × = 27. 2V
= 0.53×10
–10
v π 29.
=
2√2v
x√ 2
π
Answer: 2
π π
2√2
=
x√2
Sol:
T2 ⇒ A = 45°
P =
T1 –T2
265
5 =
T1 –265
T1 – 265 = 53
T1 = 318 K
T1 = 45°C
30. 34.
Answer: 3 Answer: 1
Sol: Sol:
2
ω x = V∘ = ω √ A
2
− x
2 We have,
μ2 μ1 μ2 –μ1
2 2 2 2
A − x = x ω − =
v u R
or,
1.5 1 1
31. v
=
40 cm
–
25 cm
→ → →
32. E = B × c and E = B0 c
Answer: 4 →
√3 1
here, E( (− ĵ ) + î )
2 2
Sol:
and E0 = 30c
Potential difference across C si 10 V. →
1 √3 z
E =( î − ĵ )30 csin[ω(t − )]
∴ q = CV = 6×10 = 60 μC 2 2 c
33.
36.
Answer: 2
Answer: 4
Sol:
Sol:
2 4
I = 2[5(0. 2) + 2(0. 4) Zero (No potential difference across
voltmeter).
37. 39.
Answer: 3 Answer: 4
Sol: Sol:
KE of rotation = 1
Iω
2
=
1
× (
2 2
mr ) ω
2
Wheatstone bridge is balancd.
2 2 5
P R
=
= 1
2
×
2
5
× 1 × (
3×3
100×100
) (50 × 50) Q S
40 60 4
Joule
9
⇒ = =
10 15 1
20
Answer: 2 So,
⇒ I1 = 1. 5 I2
asinθ = nλ where n=1
Heat produced in AB = I
2
Rt
θ = sin
−1
(
λ
a
) .......... (1) 1
=
According to question 2 2
(1. 5I2 ) × 40 × t = 90I t
2
–3
λ = 2 × 10 m
Heat produced in BC, = I
2
Rt
–3 1
a = 4 × 10 m .......... (2)
=
From equation (1) and (2) 2 2
(1. 5I2 ) × 10 × t = 22. 5I t
2
θ = sin–1(1/2) ⇒ θ = 30°.
Heat produced in AD = I
2
2
Rt
=
2 2
I × 60 × t = 60I t
2 2
Heat produced in DC = I
2
2
Rt
=
2 2
I × 15 × t = 15I t
2 2
40.
Answer: 3
Sol:
3×16 = 6 ×v2
v2 = 8 m/s
KE = × 6 × (8)2
41. 43.
Answer: 4 Answer: 2
Sol: Sol:
Fringe width :
Dλ
β =
d
β2 λ2 D2 d1
According to question, β1
=
λ1 D1 d2
d1
Here, D2 = 2D1 & d2 =
2
β2 λ2 (2D1 ) d1 λ2 44.
= = 4
β1 λ1 D1 d λ1
Answer: 2
1
( / )
2
β2
= 4
λ2
=
4×4×10
−7
= 2. 5
Sol:
−7
β1 λ1 6.4×10
Stress is on x-axis
−4
β2 = 2. 5β1 = 2. 5 × 10
∵ slope of B is more
42.
∴ B is more elastic
Answer: 1
45.
Sol:
Answer: 3
T.E. = K.E. + P.E.
Sol:
=
[v]=[M
0 1
L T
−1
] ; [a]=[M
0 1
L T
−2
]
[F ]=[M
1 1
L T
−2
] ; [W ]=[M
1 2
L T
−2
]
= 2500 J
Chemistry - Section A
46. 49.
Answer: 3 Answer: 2
Sol: Sol:
1 2 200
PS = × 100 + 50 × =
3 3 3
100/3
1
XB = =
200/3 2
50.
3, N, N–trimethylpentan-3-amine Answer: 3
47. Sol:
a)
+ − − −
Answer: 3 NaCl → Na (10e ) + Cl (18e )
Sol: b) BeCl2 → Be
2+
(2e
−
) + 2 Cl
−
(18e
−
)
Given V1 = 8cm3
c)
2+ − − −
MgF → Mg (10e ) + 2F (10e )
2
V2 = 80 cm3
d)
2+ − 2− −
CaS → Ca (18e ) + S (18e )
n=5
51.
T = 27 + 273 = 300K
Answer: 2
V2
ΔST = 2 .303 nRlog
V1 Sol:
−1 Metamers
ΔST = 95 .74 JK
48.
Answer: 4
Sol:
% of Atomic Atomic Simplest
Element
element mass ratio ratio
80 6.67
C 80 12 12
= 6.67
6.67
= 1
20 20
H 20 1 1
= 20
6.67
= 3
55.
The above given reaction results in the
formula - Answer: 4
Δf H(PCl3 , g) =ΔHatomization (P, s) + 3× Sol:
Δf H(Cl, g)−(B. E(P − Cl) × 3)
l2 is solid and sublimes at ordinary
Substituting the value in above formula- temperature because of weak vanderwaal's
force between l2 molecules.
306 kJ / mol= 314 kJ / mol
Ea 10
∴ log 2 = ×
2.303×8.314 308×298
3
Ea = 52. 903 × 10 J
or Ea = 52. 903 kJ
58. 60.
Answer: 3 Answer: 4
Sol: Sol:
Cr2O3 + 2Al → Al2O3 + 2Cr MnS is pink and the rest of them are black.
Here we can see that, aluminium metal 61.
displaces chromium metal and therefore this
is metal displacement reaction. Answer: 1
59. Sol:
(iii) (iv)
62. 65.
Answer: 3 Answer: 1
Sol: Sol:
For WAWB type of salt Conjugate acid of (II) is stabilized by charge
1 delocalization.
pH = [pKw +pKa -pKb ]
2
66.
pKw of water at 25° C is 14.
Answer: 4
pKa of acetic acid
Sol:
pKa = − log Ka
Acidic buffer solution: Acidic buffer are
pKa = - log 1.8×10 -5 -5
= - (log 1.8 + log 10 ) solution of a mixture of weak acid and salt of
its conjugate base of that acid with a strong
= - (0.255 - 5) = 4.745 base.
pKb of ammonium hydroxide a) HCN + NaCN
2
[14 + 4. 745 − 4. 745] =7
So pH = 7 (Neutral solution)
63.
Answer: 4
Sol:
64.
Answer: 3
Sol:
(1) Nitrogen can not form pentahalide due to
the absence of vacant d- d-orbitals in
outermost orbitals
(2) EN=N>P
67. 70.
Answer: 3 Answer: 1
Sol: Sol:
Both Assertion and Reason are correct and
Reason is correct for the Assertion.
71.
Answer: 2
S = [Ne] 3s2 3p4 3d0
Sol:
In the given reaction
S* = 3s2 3p3 3d1
2AgCl(s) + H2 (g) (1 bar) → 2HCl (aq) +
2Ag
Silver is undergoing reductino Ag+ → Ag
O = [He] 2s2 2p4
Hence it will act as cathode in following cell.
Pt(s) | H2(g), 1bar | 1m HCl (aq) |1mAg+
(aq) | Ag(s).
72.
Answer: 1
Sol:
68.
Answer: 3
Sol:
73.
69.
Answer: 3
Answer: 2
Sol:
Sol:
Anhydrous aluminium chloride is hydrolysed
E = E –
o 0.0591
log
1
partly with the moisture in the atmosphere
2
to give HCl gas. This HCl combines with the
+2
[Zn ]
2 Λm (H
o + o
)+Λm (SO
2−
). . . . (1)
Sol:
4
Mole at equilibrium
o o +
Λm (K2 SO4 )= 2 Λm (K ) 2
x
KC =
(a–x)V
o 2−
+ Λm (SO ). . . (2)
4
o
2z+x−y Answer: 3
Λm (CH3 COOH)=
2
x−y
Sol:
o
Λm (CH3 COOH)= z +
z
Methyl Cyanide on reacting with a Grignard’s
75. reagent produces a ketone
+H2 O
−−−
−−→
–MgINH
2
79. 83.
Answer: 4 Answer: 1
Sol: Sol:
Structure of [Cu(NH3)4]SO4 is as follows: Tetrahedral complex rarely formed low spin
complex because Δt is not large enough to
facilitete back pairing
84.
Answer: 2
Sol:
85.
Answer: 2
Sol:
The Mond process, sometimes known as the
carbonyl process, This process converts
81. nickel oxides into nickel metal with very high
purity being attainable in just a single
Answer: 4 process.
Sol: 330–350K
Ni + 4 CO −−−−−→ Ni (CO)
4
Square planer complex do not show optical Impure Nickel
−−−
− → Ni + 4 CO
symmetry. pure
82.
Answer: 3
Sol:
Valine is one of the 20- essential amino acid
for metabolism.
86. 89.
Answer: 2 Answer: 3
Sol: Sol:
In aqueous solution, more than 99% of i) H can't precipitate the salt of Zn from its
glucose molecules, exist in cyclic isomeric solution because H has less reducing
form. This conversion to a ring form arises property as compared to Zn.
from the open-chain form by a nucleophilic
addition reaction between the aldehyde ii) H can't precipitate the salt of Cu from its
group at C-1 and the hydroxyl group at C-4 solution because H has less reducing
or C-5, yielding a hemiacetal group -C(OH)- property/power as compared to Cu.
O-, at C-1. The reaction between C-1 and C- iii) H can precipitate the salt of Ag from its
5 creates a molecule with a six-membered solution because H has higher reducing
ring, called pyranose. The position of the property/power as compared to Ag.
hydroxyl on the C-1 determines the alpha or
the beta form of the pyranose. In general, β- iv) H can't precipitate the salt of Fe from its
D-glucopyranose may also be called as β-D- solution because H has less reducing
glucose. property/power as compared to Fe.
90.
Answer: 4
Sol:
88.
Answer: 2
Sol:
Prussian blue is a dark blue complex.
Synthetic pigment by oxidation, of ferrous
ferrocyanide salts. It contains ferric
hexacynoferrate (II) in a cubic lattice crystal
structure.
91. 94.
Answer: 3 Answer: 1
Sol: Sol:
Skeletal system consists of a framework of Accessory pigments like carotenoids and
bones and a few cartilages. In human chlorophyll b enhance the efficiency of
beings, this system is made up of 206 bones photosynthesis by absorbing a broader
and a few cartilages. It is grouped into two spectrum of light wavelengths, which allows
principal divisions – the axial and the plants to capture more energy from sunlight
appendicular skeleton. compared to relying solely on chlorophyll a.
Axial skeleton comprises 80 bones If both Assertion & Reason are True & the
distributed along the main axis of the Reason is a correct explanation of the
body. The skull, vertebral column, Assertion.
sternum and ribs constitute axial skeleton.
95.
The bones of the limbs alongwith their
girdles constitute the appendicular Answer: 1
skeleton. Sol:
92. 12th NCERT Page No. 28
Answer: 4 96.
Sol: Answer: 4
Perianth is the collective name of the Sol:
nonessential floral organs. Calyx and corolla
are called as accessory whorls. In some Column-I Column-II
plants they are not differentiated from one (a) Making multiple
copies of any template (iii) Cloning
another, in such case they are termed as DNA
perianth. Hence, the perianth is the term (b) Technique to alter
(iv) Genetic
used when calyx and corolla are similar. the chemistry of genetic
engineering
material
93. (c) Technique of using
live organisms or
(i) Biotechnology
Answer: 4 enzymes to produce
products
Sol: (d) Separate bands of
DNA are cut from (ii) Elution
Ecology is the study of living organisms agarose gel
(plants, animals, microbes) and their
interaction with the environment.
Physiological ecology ;Physiological ecology
refers to the study of physiology of different
organisms. This in turn helps to explore their
mechanism of adaptation to the respective
environment in terms of reproduction and
survival.
97. 99.
Answer: 2 Answer: 3
Sol: Sol:
ALVEOLAR PRESSURE- Nerves arising from brain are called cranial
nerves. There are 12 - pairs of cranial nerves
Inspiration is an active process whereas expiration is found in reptiles, birds and mammals but
a passive process. amphibians and fishes have only 10 - pairs of
It is the pressure of the air which is moving inside your cranial nerves (Accessory spinal and
lungs or outside. This pressure is negative at the time of hypoglossal nerves are absent).
Inspiration as the air moves out from the mouth to the
lungs where the alveoli are situated at a lower level. So Fifth cranial nerve of frog is
calledTrigeminal nerve.
And at the time of Expiration, this value of pressure is
positive as air flows out from the region of alveoli in the The vagus nerve, is the tenth
lungs at lower pressure to the higher pressure cranial nerve or CN X, and interfaces with the
outside. During expiration, muscles of the diaphragm parasympathetic control of the heart, lungs,
relax. and digestive tract. The vagus nerves are
normally referred to in the singular.
Inspiration occurs via the active contraction of muscles –
such as the diaphragm. The ophthalmic nerve (CNV1) is a terminal
branch of the trigeminal nerve (along with
Hence, the correct option is "2" - Inspiration is an the maxillary and mandibular nerves). It
active process whereas expiration is a passive process. provides sensory innervation to the skin,
98. mucous membranes and sinuses of the upper
face and scalp.
Answer: 1
The optic nerve connects the eye to the
Sol: brain. The optic nerve carries the impulses
formed by the retina, the nerve layer that
(A) Family - (5) Solanaceae
lines the back of the eye and senses light
(B) Kingdom - (4) Plantae and creates impulses. These impulses are
dispatched through the optic nerve to the
(C) Order - (2) Polymoniales brain, which interprets them as images.
(D) Species - (1) nigrum 100.
Answer: 2
Sol:
In solanaceae family, ovary is superior,
oblique ovary. The gynoecium is located in an
oblique position relative to the flowers
median plane. Carpels are obliquely placed
and ovules on swollen axile placenta.
In Cruciferae family, parietal placentation are
occurs.
In Malvaceae family, axial placentation are
occurs.
In Poaceae family, basal placentation are
occurs.
Hence, the correct answer is Solanaceae.
101. 104.
Answer: 4 Answer: 4
Sol: Sol:
same ecological niche, Explanation: An Biotechnology is the branch of biology that
ecological niche is the role and position comprises of living systems and organisms
a species has in its environment and how it for developing new and useful products.
meets its needs of food and shelter,
how it surviveand reproduce. Two different The definition given by the European
species cannot share same Federation of Biotechnology is a
ecological niche as theirrequirement is comprehensive one and comprise of
different from each other. traditional and modern view.
108.
Answer: 3
Sol:
Sensory nerves found in the epidermis
mediate touch reception, pain, and thermal
sensation. The skin is innervated by two
types of nerve fibers, sensory and
autonomic. Nerve fibers innervating the skin
originate from dorsal root ganglia nerve cell
bodies of sensory nerves .The sensory
nerves elongate from the dorsal root
ganglion and migrate toward the In cyclic photophosphorylation only
skin.Sensory nerves penetrate the basement photosystem I is active. movement of the
membrane and innervate the epidermis by electrons in a cyclic manner for synthesizing
moving vertically, terminating at the granular ATP molecules.occur in both stroma and
layer of the epidermis. grana thylakoid.
109. 111.
Answer: 2 Answer: 1
Sol: Sol:
E.P. Odum (1969) defined ecology as Parturition (giving birth after the full
“the study of structure and function of development of the fetus) is induced by the
nature” . signals released through the developing fetus
American biologist at the University of when the oxytocin hormone is released from
Georgia known for his pioneering work on the pituitary gland. This is known as fetal
ecosystem ecology ejection reflex.
This causes contractions in the uterine walls
that trigger the release of oxytocin hormone
which further increases the contraction rate.
These contractions with the help of oxytocin
hormone helps in the expulsion of the fetus
out of the uterine cavity of the mother.
Hence, the correct answer is option "1"
- II→I →IV→ V→ III
112. 115.
Answer: 4 Answer: 3
Sol: Sol:
Correct statements Here the hormone can be ADH . Because,
here the target tissue is kidney cell and the
Origin of replication' is a sequence from ADH mainly acts on collecting ducts of the
where replication starts by binding of kidney and increases the water reabsorption
polymerase enzyme. in this part.
DNA ligase acts on cut DNA molecules and 116.
joins their ends.
Answer: 2
Plasmid is autonomously replicating circular
extra-chromosomal DNA. Sol:
More than 900 restriction endonucleases A is desert.
have been discovered from over 230 strains
of bacteria. B is grassland.
The amount of blood pumped by heart per F stands for Arctic and Alpine Tundra.
minute is called cardiac output or heart 117.
output.
Answer: 2
114.
Sol:
Answer: 2
The above given figure is norplant.
Sol:
Norplant is placed subcutenous and having
Mucor and Rhizopus are fungi that belong to levonorgestral.
the class Phycomycetes.
These having 6 match stick like cyclinder
While other option are not :- which is effective up to 5 years.
Ascomycetes → Includes sac Norplant having 2 cyclinder are effective till 2
fungi like Penicillium and Saccharomyces; years.
they reproduce sexually with ascospores in
an ascus. 118.
Cuboidal/Columnar involved in functions like Two male gametes are produced from a
secretion and absorption. single pollen grain in flowering plants. Pollen
grains released from pollen-sacs at the two-
154. celled stage, wherein the generative cell
Answer: 2 divides further to form two male gametes.
They are then released into the embryo sac.
Sol: They fuse with the female gametes for the
formation of the embryo (egg) and
Dragonflies are the natural predators of endosperm (central cells). Once pollination is
mosquitoes. Hence, they can be used as achieved, the pollen tube grows up through
biocontrol agents to protect the crops from the style and stigma and towards the ovules
mosquitoes. in the ovaries. In the pollen grains, the germ
155. cells divide. This releases two sperm cells
that move down the pollen tube.
Answer: 1
One meiosis gives rise to four pollen grains.
Sol: Each of these pollen grain gives rise to 2
male gametes. Consequently, the overall
Crossing over is the process of exchange of
outcome of meiosis is 8 male gametes.
genetic material between non-sister
In given question, there are 21MMC in an
chromatids of homologous chromosomes
anther then the number of male gametes
which produce new genetics combinations.
produced from them, is -
Further, the independent assortment is
21 x 8 = 168.
segregation of factors for a trait independent
of other factors during gamete formation 158.
followed by their random rearrangement in
progeny thereby producing both parental and Answer: 4
new combinations. The linkage is the Sol:
tendency of closely placed genes on a
chromosome to stay together during NCERT 11th Page No.116
inheritance (no crossover and independent
assortment); it produces more parental The body of the frog is divisible into head
combination and less/no new combinations and trunk. Neck and tail are absent in a frog.
of the gene. Frog's forelimbs and hind limbs help in
Completely linked genes do not show leaping, swimming, burrowing, and walking.
crossover and independent assortment, The hind limbs of frogs have five digits while
thereby produce only parental the forelimbs end in four digits. Hind limbs
combinations; are more muscular and larger when
compared to forelimbs.
A number of recombinant types in a
population depends on upon crossover
frequency between the genes; the higher the
crossover frequency, the higher is the
number of recombinant types.
159. 163.
Answer: 2 Answer: 2
Sol: Sol:
Lysosomes release the enzymes on activation An informosome is a particle found in animal
by intracellular environment. In plants cells, cells that is made up of a special protein and
particularly at the time of seed macromolecular ribonucleic acid (RNA). The
germination, lysosomal enzymes degrade protein in informosomes may help move
macromolecules like starch and reserve mRNA from the nucleus to the cytoplasm,
proteins into glucose and amino acids protect mRNA from destruction, and control
respectively. the rate of protein synthesis.
160. 164.
Answer: 4 Answer: 2
Sol: Sol:
12th NCERT PAGE NO.- 106 Ribosomes are the cell organelle which
is non- membranous and found in both
161. Prokaryotes and Eukaryotes. Prokaryotes and
Answer: 3 eukaryotes are the two different types of
cells.
Sol:
Eukaryotic cells contain membrane-
In seed plants, fertilization is called bound organelles, such as the nucleus,
Siphonogamy because the male gametes are endoplasmic reticulum, mitochondria
brought to the egg present in female while prokaryotic cells do not.
gametophyte by a pollen tube.
165.
Internal fertilization: Syngamy occurs inside
the body of organisms. It is present in the Answer: 3
majority of plants like Bryophytes Sol:
to Angiosperms. In all these organisms egg
is formed inside the female body where Hybrid varieties of several of our food and
syngamy occurs. The male gametes either vegetable crops are being extensively
through water or pollen tube, are transferred cultivated. Cultivation of hybrids has
to female gametes. In order to enhance the tremendously increased productivity. One of
chances of syngamy large number of sperms the problems of hybrids is that hybrid seeds
are produced in these organisms and to have to be produced every year.
compensate for this, there is a significant
reduction in the number of eggs produced. If the seeds collected from hybrids are sown,
the plants in the progeny will segregate
162. and do not maintain hybrid characters.
Production of hybrid seeds is costly and
Answer: 3 hence the cost of hybrid seeds become too
Sol: expensive for the farmers.Apomictics can
also help preventing seggregation.
Class 11th NCERT Page No. 118
166.
Answer: 1
Sol:
12th NCERT Page No. 130-131
167. 172.
Answer: 4 Answer: 4
Sol: Sol:
Synthesis of DNA from RNA occurs by 12th NCERT Page No. - 156, 157, 158
reverse transcriptase enzyme in reverse
Column I Column II
transcription, discovered by Temin &
Don’t die of
Baltimore (a) AIDS (iii)
ignorance
(b) Cancer (iv) Metastasis
168.
Biological Response
(c) (i) α -Interferon
modifier
Answer: 3
(d) HIV factory (ii) Macrophages
Sol:
173.
The main difference is -
Answer: 3
The endoplasmic reticulun bearing ribosomes
Sol:
on their surface is called rough endoplasmic
reticulum (RER). In the absence of Each strand has a backbone made of
ribosomes they appear smooth and are alternating groups of sugar (deoxyribose)
called smooth endoplasmic reticulum (SER). and phosphate groups. Attached to each
169. sugar is one of four bases: adenine (A),
cytosine (C), guanine (G), and thymine (T).
Answer: 3 The two strands are held together by bonds
between the bases, adenine forming a base
Sol: pair with thymine, and cytosine forming a
12th NCERT Page No. 138 base pair with guanine. If a DNA nucleotide
chain has AGCTTCGA sequence, then
170. nucleotide sequence of other chain would be
TCGAAGCT.
Answer: 4
The correct answer is option C
Sol:
174.
Class 12th NCER Page No. 90
Answer: 2
171.
Sol:
Answer: 3
Class 11th NCERT Page No. 169
Sol:
In meiosis, the centromere divides during
Class 11th NCERT Page No. 168
anaphase II. During anaphase II, the
During the pachytene stage of prophase I in centromere of each chromosome splits,
meiosis, homologous chromosomes pair up allowing the sister chromatids to move to
to form bivalents (also called tetrads). opposite poles of the cell.