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The part of the human brain that governs memory and intelligence is Cerebrum.

Answer is : (b) three-chambered

Vertebrate hearts can be categorised by the number of chambers they have, like two-chambered (one atrium and one ventricle) in fishes, three-chambered (two atria and one ventricle) in amphibians and reptiles; and four-chambered (two atria and two ventricles) in birds and mammals.

Answer is : (c) Mature erythrocyte

Mature human erythrocytes (Red blood cells) lack a nucleus. The absence of a nucleus is an adaptation of the red blood cell for its role. It allows the RBC to contain more haemoglobin and therefore carry more oxygen molecules. It also allows the cell to have its distinctive biconcave shape which aids diffusion.

Answer is : (b) O₂ → O + O

In the stratosphere, ozone is created primarily by ultraviolet radiation. When high energy ultraviolet rays strike ordinary oxygen molecules (O₂), they split the molecule into two single oxygen atoms, known as atomic oxygen.

O₂ → O + O

A freed oxygen then combines with another oxygen molecule to form a molecule of ozone (O₃).

Answer is : (b) training at high altitude increases the number of red blood cells

Athletes are often trained at high altitude because the air is ‘thinner’ at high altitudes, means there are fewer oxygen molecules per volume of air. Every breath taken at high altitude delivers less of what working muscles require. To compensate for the decrease in oxygen there occurs more production of red blood cells to aid in oxygen delivery to the muscles.

Correct option is (C) S^2- >Cl^-  >K⁺ >Ca²⁺ 

Isoelectronic species are those species which have same number of electrons. 

As all the given elements are isoelectronic with each other. 

Thus, the radii/size of isoelectronic species is inversely proportional to the atomic number, i.e. size \(\propto \frac{1}{Z}\)

Thus, the correct order is  S^2- >Cl^-  >K⁺ >Ca²⁺ 

(B) S₁ is closed but S₂ and S₃ are open.

Answer is : (c) 12

Given, 4 x 4 x 4 cubes is made 64 faces 1 x 1 x 1 cubes.

Total cubes = 64, White = 20, Red = 44

To find minimum number of visible white box counting total visible faces of unit cube.

Total number of faces of small cube on bigger cube except boundary cubes = 4 x 6 = 24

Counting boundary cubes = 16+8+8 = 32

∴ Total visible faces = 56

But we have 44 red cube.

∴ Minimum number of white faces cubes which are visible = 56 - 44 = 12

Correct option(D) 28 and 35

Explanation:

2(a + b) + ab = 16 ... (1)

2(b + c) + bc = 24 ... (2)

2(c + a) + ca = 31 ... (3)

From equation (2), equation (3) =>(a - b) (2 + c) = 7 ... (4)

From equation (2) and equation (4)  =>4a = 2 + 5b ... (5)

Solve equation (1) and (5)

b = 2 a = 3, c = 5

Volume = 30

Answer is : (c) SeF₄ and CH₄ have same shape

PH₅ does not exist due to very less electronegativity difference between P and H. Hydrogen is slightly more electronegative than phosphorus, thus could not hold significantly the sharing electrons. On the other hand, BiCl₅ does not exist due to inert pair effect. This is because on moving down the group, +5 oxidation state becomes less stable while +3 oxidation state become more stable due to inert pair effect.

In SO₂, pπ-dπ and pπ-pπ both types of bonds are present.

SeF₄ has sp³ d-hybridisation whereas CH₄ has sp³ -hybridisation. Thus, they both have different geometry.

\(I^+_3\) has a bent shape due to the presence of 2 lone pairs on central I atom.

Correct option is (c) Si < P < C < N

On moving across a period from left to right in periodic table electronegativity increases. This is because across the period the size of an atom decreases. While on moving down the group, electronegativity decreases. Thus, the correct order of electronegativity is

Si < P < C < N 

(1.8) (2.1) (2.5) (3.0)

Answer is : (a) 4

Four electrons are required to reduce one molecule of oxygen to water during mitochondrial oxidation.

O₂ + 4e^- + 4H⁺ → 2H₂O

This process mentioned above takes place during oxidative phosphorylation. It is the metabolic pathway in which cells use enzymes to oxidise nutrients, thereby releasing energy which is used to produce ATP.

 Answer is : (c) Glucose to CO₂ and H₂O by Saccharomyces

Conversion of glucose to CO₂ and H₂O by Saccharomyces is a reaction which takes place in aerobic conditions, i.e. in the presence of oxygen.

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Answer is : (d) 0.1 mole

A mole is the quantity of a substance whose weight in grams is equal to the molecular weight of the substance. 1 mole is equal to 1 moles Glucose, or 180.15588 grams.

∴ 18 g of glucose = x mole × 180 g

x mole = 18/180 = 0.1 mole

∴ An amount of 18 g glucose corresponds to 0.1 mole.

Answer is : (b) sugars

DNA polymer is made up of nitrogenous base, a sugar and one or more phosphate. Optical activity results due to the molecular asymmetry. The nucleic acid bases have a plane of symmetry. Hence, they do not induce optical activity. Sugars are asymmetric and cause optical activity of DNA.

Answer is : (b) 37°C

Camel belongs to class–Mammalia. Both birds and mammals are homeothermic and have a fixed 37°C body temperature. So, the DNA polymerase isolated from a camel will work efficiently at temperature near its body temperature.

Answer is : (b) P–v, Q–iv, R–i, S–iii

– Hydrolases catalyse transfer of a chemical group from one substrate to another.

– Lyase catalyses removal of chemical groups from a substrate.

– Isomerase catalyses interconversion of optical, geometric or positional isomers.

– Ligase catalyses linking together of two compounds.

Answer is : (a) latitude

Latitude and temperature are related to each other in a way that, as we approaches the equator, the temperature gets warmer and as we approaches the poles, it gets cooler. Since, same vegetation grows in the same climatic zone, therefore similar type of vegetation can be observed in the same latitude.

Similar type of vegetation can be observed, in the same latitude.

Tree-Bird-Avian parasite is ecological food chain does not represent an erect pyramid of numbers.

Answer is : (b) Tree–Bird–Avian parasite

Tree–Bird–Avian parasite does not represent an erect pyramid of number. Instead, it is an inverted pyramid of number. All ecological pyramids of number are erect except in parasitic food chain, where one primary producer supports numerous parasites which further support more hyperparasites.

Correct option  (D) The actual pressure is about 1.25 times the atmospheric pressure 

Explanation:

Blood pressure is gauge pressure = 190 mm

Hg Atmospheric pressure = 760 mm Hg

Actual pressure = 190 + 760 mm Hg = 950 mm Hg = 1.25 x 760 mm Hg

Correct option  (B) 2

Explanation:

only possible when sin 3x = 1 & sin 7x = 1

sin 3x = 1

sin 3x = sin (4n + 1) π/2 , n ∈ I 

3x = (4n + 1) π/2 ⇒ x = (4n + 1) π/6

sin 7x = sin(4m + 1) π/2, m ∈ I 

x = (4m + 1) π/14

for common solution

(4n + 1) π/6  = (4m + 1) π/14 

Solving these 1 = 3m – 7n

First solution is m = 5, n = 2

Second solution is m = 12, n = 5

So two solutions are possible

Correct option  (D) Gets cooked at the same time at all the three places

Explanation:

Pressure cooker is used.

Answer is : (d) 30

Let the speed of B = x km/h and the speed of A = 3x km/h

Distance between A and B = 30 km

Given, distance between them decrease at 2 km per minutes.

∴ Distance decrease in one hour = 2 x 60 = 120 km

∴ Total distance travelled by A and B in one hour = (x+3x) km = 4x km

∴ Speed = 120/4 = 30 km/h

Hence, speed of B = 30 km/h

Speed of A = 90 km/h

Distance travelled by A and B after 10 min = 2 x 10 = 20 km

So, remaining distance = (30 - 20) = 10 km

Time taken by B to distance travelled 10 km = (10/30 x 60) = 20 min

Total time taken by A = 20+10 = 30 min

Answer: B. 

Number less than 1000 can write 

abc =100a + 10b  +c

 where a, b, c ∈  {0,1 2 3....... 9 }  and a+b+c > 0

 The sum of digits of this number is ( a+b+c).

. Given, 100a+10b+c= 6 (a+b+c)

∴ 94a+ 4b -5c = 0

 Clearly, a > 0. No solution 

∴  a = 0 then 4b = 5c 

 This is possible only 

b = 5 and c = 4 

∴Number is 54.

 Hence, only one number i.e., 54.

Correct option (C) only II and III are true 

Explanation:

P(sin² x) = P(cos² x)

P(sin² x) = P(1 – sin² x)

P(x) = P(1 – x) ∀ x ∈ [0, 1]

Differentiable both sides w.r.t. x

P'(x) = – P'(1 – x)

So P '(x) is symmetric about point x = 1/2

So P '(x) has highest degree odd 

⇒ P(x) has highest degree even 

Answer is : (b) 26

We have, side of quadrilateral has distinct integer second largest size has length 10.

Let a = 8, b = 9, c = 10, (All are distinct)

We know, in quadrilateral Sum of three sides is greater than fourth side

∴ a+b+c > d

⇒ 8+9+10 > d

⇒ d < 27

∴ Maximum length of 4th side is 26.

Answer is : (b) the cube will cool faster because it has a larger surface area

Area of cube is more than that of a sphere for same mass and density. Cube also have sharp edges that radiates more effectively than a flat surface. So, rate of cooling for cube is much rapid than sphere. Effect of sharp edges is prominent only at very high temperatures.

Answer is : (c) the balance A will read less than 2 kg and B will read between 3 kg and 5 kg

When block is dipped in water, it displaces some water which exerts buoyant force on block. As a result, reading on scale A will be lower than 2 kg. Due to reaction of block (which is equal to buoyant force), beaker of water is pushed. So, reading of scale B will be more than 3 kg.

Correct option  (D) 80 to 100 dB

Explanation:

Loudness of sound in decibel dB = 10 log₁₀ (I/I₀)

when intensity of sound become 100 I then new decibel level = dB' = 10 log₁₀ (100I/I₀)

dB' – dB = 10 log ₁₀ 100 

dB' – dB = 20

∴ decibel rise by 20 dB 

only one option i.e. 80 to 100 dB match with it

Answer is : (d) The radius of the orbit will not change

When star shrinks without losing its mass, its gravitational acceleration on its surface increases but there is no change in force exerted by this star on a distant object like a planet. Force of gravitational attraction of star on planet is

F = GMm/r²

where, M = mass of star, m = mass of planet and r = orbital radius of planet. As, this force remains same there is no change in orbital radius of planet.

Answer is : (d) 4.48 L

C(s) + O₂(g) → CO₂(g)

1 mole of carbon reacts completely with 1 mole of oxygen to produce 1 mole of CO₂.

12 g of C reacts = 1 mole of O₂

2.4 g of C reacts with = 1/12 x 2.4 = 0.2 mole of O₂

At STP 1 mole of O₂ contains = 22.4 L

∴ 0.2 mole of O₂ contains = 22.4 x 0.2 = 4.48 L

Correct option (C) ATP alone.

 Explanation:

In cyclic photophosphorylation only ATP is formed.

Correct option  (A) kill the fast growing bacteria more than the slow growing

Explanation:

Penicillin inhibit the cell wall formation in bacteria thus it kill rapidly growing bacteria more than the slow growing bacteria. 

Correct option: (c) 3

Answer:  1000mm²

Explanation:

In lungs, alveoli are tiny sacs which allow oxygen and carbon dioxide to move between the lungs and bloodstream. 

Average radius of spherical alveoli is 0.1 mm

Total number of Alveoli is 400 × 2 = 800 million (since 400 million alveoli in 1 lung)

Surface area of a sphere is 4πr²r²

Therefore, total respiratory surface Area =  4πr²r² × 800 million= 1000mmm²m² (approx)

Correct option is (b) cork cambium and cork

In the dicot stem, the cortical cells get differentiated to give rise to another meristematic tissue, which is called cork cambium or phellogen. On the other side, it forms phellem (cork) and in the inner region it forms secondary cortical cells (phelloderm).

Correct option is (d) Sucrose

Sucrose shows the most substrate specificity since it hydrolyses only the disaccharide, sucrose.

Answer is : (a) zero, positive

∆H for this process = C_V∆T = 0 (at constant temperature)

∆S for this process will be positive that is ∆S > 0, the randomness increases the molecules of gases A and B gets intermixed with each other, when the partition is removed.

Answer is : (d) same as that of a hydrogen molecule

Average kinetic energy depends upon the temperature and not on the type of gases involved.

For any gas, (K.E) _avg = 3kT/2 per molecule

The (K.E)_avg of a deuterium molecule is same as that of hydrogen molecule.

Correct option is (c) Na⁺ influx

As the membrane potential is increased, sodium ions channels open, allowing the influx of Na⁺ ions into the cell. The inward flow of sodium ions increases the concentration of positively charged cations in the cell and causes depolarisation, where the potential of the cell is higher than the cell’s resting potential.

Correct option is (b) Release of glucose

Glucose is stored in the liver as glycogen. Glycogen can be converted to free glucose by the process of glycogenolysis, which involves the activation of a phosphorylase enzyme by the hormone glucagon. Glucagon is made by the pancreas and is released when the blood sugar levels fall. There release of glucose is a homeostatic function of liver that is controlled and monitored in the pancreas.

Correct option is (a) centrosome

Centrosomes are made up of a pair of centrioles and other proteins. The centrosomes are important for cell division and produce microtubules that separate DNA into two new identical cells.

Answer is : (a) P-ii, Q-iii, R-i

– A neurogenic heart requires nervous input to contract. It is seen in crustaceans like king crab.

– Bronchial hearts are myogenic accessory pumps found in coleoid cephalopods like shark that supplement the action of the main, systemic heart.

– Pulmonary heart is found in humans where the portion of the circulatory system carries deoxygenated blood away from the right ventricle of the heart to the lungs and returns oxygenated blood to the left atrium and ventricle of the heart.

Answer is : (d) R and R

Both thermophiles and psychrophiles will show same enzymatic reaction graph. Mostly proteinaceous enzymes are labile to temperature. Thermophiles live at very high temperature while psychrophiles live in the range of −20°C to +10°C. In either case, rising temperature will first raise the rate of reaction but if temperature is still raised continuously, enzymes get denatured, hence reaction rate decreases.

Correct option is (d) I^- > I > I⁺

Anion is formed by the gain of electron to the neutral atom and cation is formed after the loss of electron from the neutral atom. Hence, cation has smaller size due to increased nuclear charge whereas anion has bigger size than its neutral atom.

Correct option  (B) less pO₂ and pCO₂

Explanation:

Pressure gradient is essential for movement of gases in and out of the body. 

Correct option  (A) P and Q are peripheral membrane proteins.

Explanation:

Peripheral proteins can be detached earily

Correct option  (B)  5 

Explanation:

Recombinants formed = 10% (AB 5% & ab 5%)