VITEEE PCBE Mock Test - 9 - JEE MCQ

Bivalent or tetrad formation takes place during the zygotene stage of prophase I, after synapsis has occurred and homologous chromosomes form pairs. However, the bivalent is distinct only in the next stage, pachytene.

The lysosomes may be called "suicide bags’ of the cell in view of their autolytic role, or "disposal units’ of the cell because they digest the incoming food materials and remove the foreign bodies, toxic molecules, and debris, or "recyling centres" as they break down worn out cells cell organelles to component molecules for building organelles and cells.

Nucleolus is a dense, rounded, dark-staining, granular structure without a limiting membrane. It consists largely of RNAs and proteins. Nucleolus syntesizes and stores RNA. It also receives ribosomal proteins from the cytoplasm for storage. It forms ribosomal subunits by wrapping the RNAs with nitosomal proteins. The ribosomal subunits later have the nucleus through the nuclear pores.

In gout, there occurs a defect in uric acid metabolism resulting into its elevated level in blood (hyperuricemia). This is followed by precipitation of excessive uric acid which gets deposited in the joint spaces. These deposited crystals of uric acid causes pain in different bony joints.

The last two pairs i.e. 11th and 12th pairs ribs remain free anteriorly, hence, they are called as floating ribs.

• Parturition starts with the signal released by the fetus and the placenta.
• These act on the pituitary to release oxytocin.
• Oxytocin acts as a stimulant leading to contractions of the uterine muscles.
• The uterine contractions feedbacks to release more oxytocin from the pituitary.
• This results in more powerful contractions of the uterus until the baby is delivered in the process of parturition.

Adaptive radiation in Australian marsupials refers to the process where several distinct species evolved from a common ancestor to occupy various ecological niches. This diversification was a result of adaptation to different environments, not due to migration or extinction.

Gynecomastia in males is not a typical feature of Down’s syndrome. Typical features include short stature, mental retardation, and characteristic physical traits like a broad palm with a single crease.

RNA interference (RNAi) protects plants from nematode infestation by silencing specific mRNA of the nematode through the formation of complementary double-stranded RNA. This prevents translation, thereby disrupting the nematode's survival.

Parasitism is a type of symbiotic relationship where one organism benefits at the expense of the other, which is harmed.

23S rRNA in the large subunit of the ribosome is catalytically active and plays a crucial role in the formation of peptide bonds during protein synthesis in prokaryotes.

Let, L = [h^ac^bG^d]
[L]¹ = [M¹L²T ^-1]^a[LT ^-1]^b[M^-1L³T ^-2]^d
[L]¹ = [M^a-dL^2a+b+3dT ^-a-b-2d]
Comparing the dimensions of M, L and T on both sides, we have
a - d = 0 ..............1
2a + b + 3d = 1 ..........2
-a - b - 2d = 0 ............3
From equation 1, a = d
and from equation 1 and 3, b = -3a
Then, substituting the value of b and d in 2,

Initial velocity of steel ball, u = 14 m/s^-1
Mass of steel ball, m = 0.5 kg
Force acting on the steel ball from the opposite direction, F = -1200 N
Time duration for collision, t = 25 ms = 25 × 10⁻³ s

Let the final velocity of the ball be v.

Applying Newton's second law of motion to the steel ball, i.e.

[−ve sign shows that now ball will move in the direction of force]

At t = 0,
y = 0.05 sin(kx),

2.5λ = 20 cm,
λ = 8 cm.

⇒ λ = 0.8 cm.

⇒ k = 2π/λ = 2π/0.8 = 5π/2.

V = 350 m/s.

From y = A sin(k(x - vt)),
y = 0.05 sin(5π/2(x - 350t))
= 0.05 sin(5π/2 x - 350t)
= 0.05 sin(5π/2 x - (5π/2)(350)t).

From the law of equipartition of energy law, the total kinetic energy of the gas is KE = f/2nRT, which is proportional to the temperature.
At absolute zero temperature, kinetic energy of the gas molecules becomes zero, but they may possess some potential energy, so we cannot say that absolute zero degree temperature is zero energy temperature.
The RMS speed of a gas is given by .
For different gases or at different temperature, it will be different. But it does not depend on the pressure.
From the ideal gas equation, PV = nRT, two different gases at same temperature, pressure and volume will have the same number of moles and same number of molecules.

sForinusoidal alternating current or triangualr and square wave alternating current the average value for a period is always zero.

But in case of following currnet peak value will not be equal to rms value.

If AC is the square wave then all these three options are possible. i.e.,

I_rms = I_av = I₀, here I₀ is peak value

For a quantity to be unit less, its dimensions= 1 = M⁰L⁰T⁰
Hence, it has to be dimensionless.
Some examples are refractive index and relative density, these are unit less and dimensionless.
Quantities like angles are dimensionless, but they have a unit.
Hence, the correct answer is never has a non-zero dimension.

Let the velocity of A and B be v_A & v_B along the line of impact after collision.

Now, net force along the line of impact is 0.
So, applying conservation of momentum

On solving eq 1 & eq 2

When the partial pressure of A is doubled, its concentration gets doubled. Since rate = k(A)², the rate becomes four times the original.

Deoxyribose is a carbohydrate. Hence, the assertion is wrong.
Deoxyribose does not have the formula C_x(H₂O)_y, but is very much a carbohydrate. Hence, the definition of carbohydrates given in the reason is not valid.
The correct definition is that carbohydrates are optically active polyhydroxy aldehydes or polyhydroxy ketones.

Freundlich adsorption isotherm is a graph between extent of adsorption and pressure at a constant temperature.

x/m = Kρ^1/n (at constant T)

Chile salt petre (NaNO₃) sodium nitrate is the nitrate ore of sodium.
It is a deliquescent crystalline sodium salt that is found chiefly in northern Chile. It is a white crystalline solid, odourless and has a slightly bitter taste. It is non-combustible and is highly soluble in water, hydrazine and ammonia. It dissolves in alcohol, slightly dissolves in pyridine, and completely insoluble in acetone.

In the above molecule, the central atom xenon undergo sp³ hybridisation, hence, the pi bonds are due to p orbitals of oxygen and d orbitals of xenon.

In the above molecule, the central atom sulphur undergo sp³ hybridisation, hence, the pi bond is pπ−dπ bond.

In the above molecule, the central atom sulphur undergo sp² hybridisation, hence, out of three pi bonds one pi bond is pπ−pπ bond and other two are pπ−dπ bonds.

In the above molecule, the central atom chlorine undergo sp³ hybridisation, hence, the two pi bonds are pπ−dπbonds.

A covalent bond exist between two similar atoms or the atoms which has less electronegative difference.
Equal sharing of electrons between two atoms takes place forming covalent bond to complete the octet.
For example, in hydrogen molecules the bond is covalent, as both the atoms are similar.

The recommended daily amount of vitamin-A for adult women is 700 micrograms. Vitamin-A is a nutrient important for good vision, growth, cell division, reproduction and immunity. It is found in spinach, dairy products, etc.

Correct Answer: R
P > Q > T
T > S > R
P > Q > T > S > R

It is not possible that three planes intersect exactly at 3  points. So, no such matrix is possible. Therefore, the answer is 0 (zero).
Thus, option A, that is, 0, is the correct answer.

Roots of the quadratic equation f(x) = ax² + bx + c are α and β.

Let D₁ be the discriminant of the above quadratic.

The difference of the roots |α - β| = D₁ / √a ...(i)

The maximum value of the above quadratic is f_max = -D₁ / 4a.

Roots of the quadratic equation g(x) = ax² + qx + r are α + δ and β + δ.

Let D₂ be the discriminant of the above quadratic.

The difference of the roots |(α + δ) - (β + δ)| = |α - β| = D₂ / √a ...(ii)

The maximum value of the above quadratic is g_max = -D₂ / 4a.

From (i) and (ii), D₁ = D₂
Thus, f_max = g_max.