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Answer is : (c) ²³₁₁Na, ²⁴₁₂Mg

Number of neutrons in the pairs given in options are as follows

(a) ¹²₆C, ²⁴₁₂Mg

No. of neutrons in C = 12 - 6 = 6

No. of neutrons in Mg = 24 - 12 = 12

(b) ²³₁₁Na, ¹⁹₉F

No. of neutrons in Na = 23 - 11 = 12

No. of neutrons in F = 19 - 9 = 10

(c) ²³₁₁Na, ²⁴₁₂Mg

No. of neutrons in Na = 23 - 11 = 12

No. of neutrons in Mg =  24 - 12 = 12

(d) ²³₁₁Na, ³⁹₁₉K

No. of neutrons in Na = 23 - 11 = 12

No. of neutrons in K = 39 - 19 = 20

Thus, option (c) is correct.

Answer is : (d) 18

Maximum number of electrons that can be accommodated in a subshell = 2(2l+1)

When l = 4

Maximum number of electrons = 2(2 x 4+1) = 18

Answer is : (c) sublimation

A mixture of NH₄Cl and NaCl can be separated by the process of sublimation. In this process, solid directly changes to gaseous state without passing into liquid state. NH₄Cl sublimes to gaseous NH₃ and HCl upon heating whereas NaCl does not sublime, the reaction can be written as

NH₄Cl(s) → NH₃(g) + HCl(g)

Correct option  (A) cut DNA at specific base sequence

Explanation:

Restriction endonuclease enzyme breaks the phosphodiester bond on specific pallindromic sequences.  

Correct option  (B) exosmosis

Explanation:

Excessive salt in pickle inhibits the bacterial growth by exosmosis because external medium become hypertonic. 

Answer is : (a) cut DNA at specific base sequences

Restriction endonuclease is an enzyme that cuts dsDNA into fragments at or near specific recognition sites (palindromic sequence) within the molecule known as restriction sites.

These enzymes are found in bacteria and archaea and provide a defence mechanism against invading viruses

Answer is : (d) Vulture since it eats the tiger, which in turn eats the goat, which eats the grass

The increase in concentration of harmful chemical substance like pesticides in the body of living organisms at each trophic level of a food chain is called biological magnification. The organism which occurs at the highest trophic level in the food chain will have the maximum concentration of harmful chemicals in its body. Since vulture occupies the top level as it eats the tiger, which eats the goat, which eats the grass in the food chain, it will have the maximum concentration of harmful chemicals in its body.

Correct option  (D) Vulture since it eats the tiger, which in turn eats the goat, which eats the grass

Explanation:

Vulture will have the maximum concentration of pesticide because it feeds on tiger which in tern eat the goat which eat the grass.

Correct option  (A) The process is adiabatic 

Explanation:

In sudden expansion gas do not get enough time for exchange of heat. 

∴ Process is adiabatic. 

Correct option(d)

Explanation:

C_t=C₀e^-kt

Correct option (A) EI > EII and AI > AII 

Explanation:

For plot between In k v/s 1/T y-intercept is ln A

& slope is -E_a/R

therefore; E_II < E_I and A_I > A_II 

Correct option(d)

Explanation:

CCl₄ has zero dipole moment due to its tetrahedral shape, all C-Cl bond moment cancel each other.

Answer is : (c) Lactic acid

During vigorous muscular activity like running, muscles perform anaerobic respiration after a while due to scarcity of oxygen. During anaerobic respiration in muscles, lactic acid is produced as a byproduct. Thus a runner will have lactic acid in his muscles after a 100 metre sprint.

Answer is : (c) Synthetic (S)

DNA polymerase is an enzyme that synthesises DNA molecules from deoxyribonucleotides, the building blocks of DNA. These enzymes are essential for DNA replication. S-phase or synthetic phase is significant due to DNA synthesis. Thus, DNA polymerase activity is highest at S-phase of cell cycle.

Correct option (C) H₂

Explanation:

H₂ is reducing agent

Correct option   (D) 2,1 

Explanation:

no. of radial node = n – l – 1 = 4 – 1 – 1 = 2 

no. of angular node = l = 1

Correct option  (C) 10⁹ 

Explanation:

During PCR, the number of DNA molecules increases by 2ⁿ . Where 'n' is number of divisions

Correct option  (B) short day plant and actually measures night length to flower

Explanation:

SDP (Short day plants) or LNP (Long Night Plants) flowers only when photoperiod is below critical day length (Critical photoperiod) or they are responsible to night length and flower when night length is above critical dark period.

In this experiment plant flowers when dark period is above 8 hrs. So, it is SDP and actually measures night length to flower.

Answer is : (b)

With respect to observer, there is no acceleration in the vertical velocity component. So, path of particle is a straight line as in option (b).

Correct option  (D) 0.03 cm 

Explanation:

x = 0.3 cm – 3 x scale division of vernier calipers

= 0.3 cm -3 x 9/100

= 30 - 27/100

= 30 - 27/100

= 3/100

= 0.03 cm

Answer is : (c) atomic mass

According to Mendeleev’s periodic law, the physical and chemical properties of the elements are a periodic function of their atomic mass.

Correct option  (C) atomic mass

Explanation:

Mendeleev’s periodic table state that the property of elements are a periodic function of their atomic mass 

Correct option (D) A₁, A_0.3 are finite sets and A_1/π is an infinite sets

Explanation:

e^iπrn is always a finite set when r is a rational & is infinite when  r = 1/π .

Correct option  (A) The largest is a and the smallest is b 

Explanation:

(i)  a + b < c + d

(ii)  b + c < d + e

(iii)  c + d < e + a

(iv)  d + e < a + b

from (i) & (iii)

a + b < e + a 

⇒ b < e 

from (ii) & (iv)

b + c < a + b

c < a

(i) – (ii) 

a – c < c – e 

⇒c > e

(i) – (iv)

(a – e) + (b – d) < (c – a) + (d – b)

from thus d > b

(i) + (iii) – (ii

 c > d

overall a is greatest, b is least 

Answer is : (a) Ser-UCU, Leu-CUC, Arg-AGA, Glu-GAG

Serine is coded by UCU, UCC, UCA, UCG, AGU, AGC

Leucine is coded by CUU, CUC, CUA, CUG, UUA, UUG

Arginine is coded by AGA, AGG, CGU, CGC, CGA, CGG

Glutamic acid is coded by GAA, GAG

Therefore, option (a) is the correct interpretation of the assigned amino acids.

Ser-UCU, Leu-CUC, Arg-AGA, Glu-GAG

Answer is : (a) Li

As the given elements Li, N, C and Be belong to same period i.e. 2nd period, so on moving from left to right in a period the atomic radius decreases because the effective nuclear charge increases. Thus, Li has the largest atomic radius among them all.

Answer is : (c) vitamin

Ascorbic acid is also known as vitamin-C, a vitamin found in citrus fruits and is an essential nutrient involved in the repair of connective tissue and the enzymatic production of certain neurotransmitters. In the body, it acts as an antioxidant, helping to protect cells from the damage caused by free radicals.

Ascorbic acid is a Vitamin.

Answer is : (c) does not change at all

Birds and mammals are endothermic animals, i.e. their core body temperature is kept nearly constant through thermal homeostasis. Therefore, if birds are moved from 30°-10°C their body temperature does not change at all.

If birds are moved from 30°C to 10°C, their body temperature does not changes at all.

Answer is : (c) Onion

Onion is a bulb, i.e. it is a modified leaf. A bulb is an underground pyriform-spherical structure that possesses a reduced convex or slightly conical disc-shaped stem and several fleshy scales enclosing a terminal bud. In Onion, the fleshy scales represent leaf bases in the outer part and scale leaves in the central region.

Virus is the smallest in size.

Correct option  (C) Onion

Explanation:

In onion modified leaves are present for food storage

Correct option  (A) Cellulose and glycogen

Explanation:

Cellulose → Homopolysaccharide of β glucose Glycogen → Homopolysaccharide of α glucose 

Correct option (C) 10 kDa

Explanation:

Molecular Mass of a base = 500 da

Total No. of bases = 10 bp

= 10 x 2 = 20 bases

Molecular mass of 20 bases

= 20 x 500 da

= 10000 dalton

= 10 kda

Answer is : (c) 10 kDa

Molecular mass of a base = 500 Da

Number of base in a dsDNA = 10 BP or 20 bases

Thus, molecular mass of a dsDNA with 20 bases = 20 x 500 = 10 kDa

Answer is : (b) 1 mg

Assuming x as the amount of ligand to occupy all the binding sites in 10 mg protein.

x mg/Protein in grams = Ligand molecular weight/Protein molecular weight

x = 2500/25000 x 10 = 1 mg

Answer is : (a) colourblind

Absence of cone cells in eyes is known as total colour blindness or monochromacy. This person views everything as if it were in a black and white television. Monochromacy occurs when 2 or all 3 of cone pigments are missing and colour and light vision is reduced to one dimension.

Correct option is (c) 2

Since the allele is recessive, both homologous chromosomes in a somatic cell of an albino person would have the allele. After meiosis-I, each end would have a homologous chromosome with the allele. As the chromosome is existing as a each chromosome and hence each end would have two copies of the allele.

Answer is : (d) Collenchyma

The stalk of plant leaf (petiole) is derived from collenchyma. Collenchyma cells are elongated cells with irregular thick cell walls that provide structural support, particularly in growing shoots and leaves. Their thick cell walls are composed of the compounds cellulose and pectin.

(C) the balance A will read less than 2 kg and B will read between 3 kg and 5 kg.

Correct option: (D) through one corner normal to the plate.

Answer is : (a) depression of melting point

Ice melts at lower temperature due to increase in pressure. As wire passes, the water formed is again freezes and hence wire passes without cutting ice.

Correct option (D) S = R\{0}

Explanation:

 cos x = 1 ⇒ x = 2nπ

cos ( √2 x) = 1 ⇒ x = √2 mπ

both can simultaneously be 1 only when x = 0 

⇒ S = R – {0} 

Correct option is (b) 6

Let us partition in to n parts and each part has sum = K, then

nK = 1 + 2 + 3 .... + 20

nK = 210

∴K divides 210. 

Also, K must be ≥ 20

Now, 210 = 2 x 3 x 5 x 7

So, proper divisor of 210 are {1, 2, 3, 5, 6,7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210}

⇒ K can be 21, 30, 35, 42, 70,105

For K = 21, we have (1, 20) (2,19) .....(10, 11)

⇒ 21 is a good number. 

For K = 42, join two-two pairs

For K = 105, join five-five pairs 

⇒ 42 and 105 are also good numbers

For K = 30, we have

{20,10}, {19,11}, {18,12}, {17,13}, {16,14}, {15, 9, 6}, {1, 2, 3, 4, 5, 6, 7, 8}

⇒ K = 30 is also good number 

Similarly, 35 and 70 also good numbers. 

∴There are total 6 good numbers.

Correct option (C) both a and b are algebraic

Explanation:

If cos 1° = p +√q  (p, q ∈ Q)

then it will be root of a quadratic equation whose other root is p – √q 

⇒ cos 1° is algebraic ⇒ sin 1° is algebraic

Correct option  (A) I only 

Explanation:

(I)  This relation is reflexive relation because every natural no. divides square of itself

a R a ⇔ a divides a²

(II)  not symmetric eg. 5 R 10 ⇒ 5 Divide 100

But 10 R 5 ≠ 10 Divide 25

(III)  Not transitivity for example

if 8 R 4 & 4 R 2 ≠  8 R 2

only (I) Option 

Correct option (C) 9 

Explanation:

Add all these p + q + r = p³ + p² + r² 

for maximum value p = 3, q = 3, r = 3

Answer is 9.

Correct option  (D) restricting viral spread to the neighboring cells. 

Explanation:

In a typical scenario, a virus defected cell will release interferons causing near by cells to heighten their anti-viral defense 

Answer is : (a) It is activated by enterokinase

Trypsinogen is an inactive substance secreted by the pancreas, from which the digestive enzyme trypsin is formed in the duodenum. Trypsinogen is converted into its active form trypsin by an enzyme enterokinase. This results in the subsequent activation of pancreatic digestive enzymes.