Monthly Mock Test (July 31) - NEET MCQ

For linear arrangement of atoms the hybridisation should be sp(linear shape, 180° angle). Only H₂S has sp³-hybridization and hence has angular shape while C₂H₂, BeH₂ and CO₂ all involve sp - hybridization and hence have linear arrangement of atoms.

• If F is applied force then acceleration of the system is F/2m + m = F/3m
• Now when we apply the force from the left, the force applied on the block m is F/3m = F/3. This will be the force in the contact.
• When we apply the force from the right from on the block will be 2Fm/3 = 2F/3, this will be the force on the contact then.

So the ratio is F/3 : 2F/3 = 1 : 3

As the mass is at rest the resultant of forces acting on it are equal to zero so forces in vertical direction are 

T₁​sin30^o + T₂​sin60^o − mg = 0

similarly in horizontal direction

T₁​sin30^o − T₂​sin60^o = 0

solving above equations will give us 

T_1​+ √3​×√3​T_1​ = 100

T₁ ​= 25N

T₂​ = 25√3​N

Among the F, O, and N, Fluorine has a higher value of electronegativity, this is the reason that fluorine can form the strongest hydrogen bond with the H atom of another molecule.

Just take an idea from the value of the energy of hydrogen bond that is formed with HF, H₂O, and NH₃

_​

means to break the hydrogen of one mole HF molecules, 10Kcal energy is required.

Each pigment has its own absorption spectrum, chlorophyll absorbs light energy in blue and red region.

Paramagnetism is caused by the presence of atoms, ions or molecules with unpaired electrons. In NO the presence of unpaired electron is clear. Therefore it is paramagnetic.

H-bond is the weakest.

ATP is injected in cyanide poisoning because it is necessary for cellular functions. ATP makes energy available at a spot away from the area of release of energy so it helps in maintaining cellular functions.

The angle between the bonds formed by p_x and p_y orbitals is the minimum i.e. 90°

Each turn of Calvin cycle generates one carbon atom hence six turns of the cycle is required to generate one molecule of hexose sugar glucose.

The principle of limiting factors was formulated by Blackmann (1905). It states that when a process is conditioned as to its rapidity by a number of separate factors, the rate of process is limited by the pace of slowest factor.

The two molecules of pyruvate are completely degraded in Krebs cycle to form two molecules of ATP, 8 NADH₂, 2 FADH₂, CO₂ and water.

If we straighten the string horizontally hypothetically and make the free body diagram for the whole two block system we get that
M₁g.sinɑ - M₂g.sinβ = (M₁ + M₂)a
For some net acceleration of the system a
Such that a = M₁g.sinɑ - M₂g.sinβ / (M₁ + M₂)
Hence if we make a free body diagram of mass 1 only we get
M₁g.sinɑ - T = M₁a
Thus we get T = M₁ ( g.sinɑ - a )
= M₁( g.sinɑ - [M₁g.sinɑ - M₂g.sinβ / (M₁ + M₂) ] )
= M₁( M₂ (sinɑ + sinβ )f / (M₁ + M₂) )

When an apical bud is present on a plant, it suppresses  the growth of axillary buds, this is called apical dominance. When in pruning apical bud is cut off the axillary buds start growing & hedge become dense

As there is no net acceleration in horizontal or vertical direction, we can say that
P = 300N
And 2S = 2000N
Thus S = 1000N

Abscisic acid (ABA), also known as abscisin II and dormin, is a plant hormone. It functions in many plant developmental processes, includsing bud dormancy. Abscisic acid is a derivative of carotenoids. It was called “abscisin II” originally because it was thought to play a major role in abscission of fruits. At about the same time another group was calling it “dormin” because they thought it had a major role in bud dormancy. The name abscisic acid (ABA) was coined by a compromise between the two groups.

RUBISCO  is the enzyme involved in Calvin cycle. Nitrogenase catalyses nitro- genation. Invertase catalyses breaking of sucrose to glucose and fructose.

H – F shows strongest H-bonds.  Linear combination of two hybridized orbitals leads to the formation of sigma bond.

Glycolysis is the first step of respiration which occurs without requirement of O₂ and is common to both aerobic and anaerobic modes of respiration.

• In all the given cases the cos component of the tension in the string would balance the weight of the block while the sine component will cancel themselves as they are in pair.
• The larger would be the angle the smaller would be the cos component but as its value is fixed i.e. is mg, we get the larger the angle the larger the tension and hence the more chances of breaking of the rope.

Let say end b has some velocity v in horizontal direction. Thus by constraint motion we get the component of velocities along the rod of both the ends must be equal thus we get, 
u.cos (90-q) = v.cos q
Thus we get v = u.tan q

Thus option D is correct

3. Log phase

Explanation: The log phase (also known as the exponential phase) is the stage of rapid growth in living organisms, where cells divide at a constant and maximum rate. This phase is marked by a high rate of metabolic activity and cell reproduction, leading to exponential growth.

In contrast:

• Senescence refers to the aging process, where growth slows down or stops.
• Dormancy is a period of suspended growth or inactivity.
• Lag phase is the initial phase of growth where cells are adjusting to their environment and growth is minimal.

Hence, the log phase is when growth is at its maximum.

Gibberellins & ABA are antagonistic with each other. ABA counteracts many effects of gibberellins like induction of hydrolases and alpha- amylases in barley seedlings.

In glycolysis 2ATP are produced at substrate level and NADP produce 6ATP by ETS and 30ATP in mitochondria so there are only two ATP produced in cytoplasm.

The bond length decreases in the order sp³ > sp² > sp.
Because of the triple bond, the carbon-carbon bond distance in ethyne is shortest.

Photosystem I is the second photosystem in the photosynthetic light reactions of algae, plants and some bacteria. Photosystem I is so named because it was discovered before photosystem II. It produces NADPH₂.

As there is no lone pair on boron in BCl₃ therefore no repulsion takes place. But there is a lone pair on nitrogen in NCl₃. Therefore repulsion takes place. Thus BCl₃ is planar molecule but NCl₃ is a pyramidal molecule.

Gibberellins stimulate the synthesis of α-amylase and proteases enzyme in germinating grains of cereals. They are involved in the conversion of starch into sugar. The proteases convert an inactive β-amylase to the active form. The active β-amylase and α-amylase together digest starch to glucose which is mobilized to meet the metabolic demands of embryo. 

Oxidative phosphorylation is the synthesis of energy rich ATP from ADP and  inorganic phosphate, that is connected to oxidation of reduced coenzymes produced in cellular  respiration.