NEET Mock Test - 1 (July 1, 2021)


180 Questions MCQ Test NEET Mock Test Series | NEET Mock Test - 1 (July 1, 2021)


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This mock test of NEET Mock Test - 1 (July 1, 2021) for NEET helps you for every NEET entrance exam. This contains 180 Multiple Choice Questions for NEET NEET Mock Test - 1 (July 1, 2021) (mcq) to study with solutions a complete question bank. The solved questions answers in this NEET Mock Test - 1 (July 1, 2021) quiz give you a good mix of easy questions and tough questions. NEET students definitely take this NEET Mock Test - 1 (July 1, 2021) exercise for a better result in the exam. You can find other NEET Mock Test - 1 (July 1, 2021) extra questions, long questions & short questions for NEET on EduRev as well by searching above.
QUESTION: 1

A ball falls vertically onto a floor, with momentum P, then bounces repeatedly. The coefficient of restitution is 1/2, the total momentum imparted by the ball to the floor is:

Solution:





QUESTION: 2

A body is projected vertically up with a certain velocity. At point P in its path, the ratio of its potential energy to kinetic energy is 36:64. The ratio of the velocity of projection to the velocity at ‘P’ is:

Solution:







 

QUESTION: 3

The radius of gyration of body about the centre of mass is 24 cm. Then radius of gyration of body about an axis parallel to the axis passing through the centre of mass and at a distance 7 cm from the centre of mass is:

Solution:



QUESTION: 4

A spherical shell of mass m and radius R is pulled on a horizontal plane by a horizontal force F acting on its centre of mass. If the shell is rolling without slipping, then the angular acceleration of the spherical shell will be:

Solution:



QUESTION: 5

A uniform rod AB of mass ’m’ length ‘2a’ is allowed to fall under gravity with AB in the horizontal position. When the speed of the rod is ‘V’ suddenly the end ‘A’ is fixed. The angular velocity of the rod with which it begins to rotate will be: 

Solution:




QUESTION: 6

The amplitude of vibration of a particle is given by  where a0, a, b and c are positive. The condition for single resonant frequency will be:

Solution:





QUESTION: 7

A particle performing SHM with frequency 10 Hz and amplitude 5 cm is initially in the left extreme position. The equation of its displacement will be (x is in meter):

Solution:




QUESTION: 8

The gravitational field at some point in space is The force exerted on a 2 kg mass placed at a point is:

Solution:




QUESTION: 9

A wire having a linear mass density of 5.0 x 10-3 kg/m is stretched between two rigid supports with tension of 450 N. The wire resonates at a frequency of 400 Hz. The next higher frequency at which the wire resonates is 500 Hz. The length of the wire will be:

Solution:



QUESTION: 10

Which of the following is correct?

Solution:
  • Sound waves require a material medium for their propagation. So the observed frequency of sound when the source moves towards the observer is different from the case when the observer moves towards the source with the same relative velocity. We say that the Doppler effect in sound is asymmetric.
  • On the other hand, no material medium is required for the propagation of light waves. So the apparent frequency is the same whether the source moves towards the observer or the observer moves towards the source. We say that the Doppler effect in light is symmetric.
QUESTION: 11

If V is speed, r is radius and g is acceleration due to gravity, which of the following is dimensionless?

Solution:

QUESTION: 12

For a man running horizontally along east at speed of 4 km/hr, rain appears to fall vertically. If he doubles his speed the rain appears to hit him at an angle at 30o with vertical. The original speed and direction of rain will be:

Solution:






QUESTION: 13

A rigid rod is placed against the wall as shown in the figure. When its velocity of the lower end is 10m/s and its base makes an angle  α=60 o with horizontal, then the vertical velocity of its end B will be:
  

Solution:

 x2 + y2 = l2 = constant 

QUESTION: 14

On the horizontal surface of a truck, a block of mass 2 kg is placed and the coefficient of friction between the block and surface is (μs = 0.6) truck starts moving with an acceleration 4 m/s2 , the frictional force on the block will be? (g = 10 m/s2)

Solution:
  • If the block has to move, it should overcome static frictional force which is,
    μmg = 0.6 × 2 × 10 = 12N
  • As the truck is moving with an acceleration, a pseudo force acts on the block which is, ma = 2 × 4 = 8N
  • As this force is not enough for the block to move, an equal frictional force acts in the opposite direction which is equal to 8N.
QUESTION: 15

A man is supplying an instantaneous power of 500 J/s to a massless string by pulling it at an instantaneous speed of 10 m/s as shown. It is known that the kinetic energy of the block is increasing at a rate of 100 J/s at that instant. Then the mass of the block is:

Solution:

QUESTION: 16

What is a necessary condition for a reaction to be spontaneous at all temperatures?

Solution:

For a reaction to be spontaneous, ΔG and ΔH should be negative.

QUESTION: 17

Each side of regular polygon of n sides has a resistance R. The equivalent resistance between any two adjacent vertices is:

Solution:
  • When a uniform wire of resistance R is shaped into a regular n-sided polygon, the resistance of each side of the polygon is R/n​.
  • Also, the polygon is equivalent to the combination of two resistances.
  • The resistance of one side,
  • The resistance of (n−1) side, 
  • Since, the two parts are parallel, hence equivalent resistance between two adjacent corners is:
QUESTION: 18

When a lens of power P (in air) made of material of refractive index 3 is dipped in a liquid of refractive index 4, the new power of lens is:

Solution:


QUESTION: 19

A point source of electromagnetic radiation has an average power output of 800 W. The maximum value of electric field at a distance 3.5 m from source will be:

Solution:

QUESTION: 20

Two plates (of area: a each) given charges + q1 and + q2 (q2 < q1) are brought closer to form a capacitor of capacitance C. The potential difference across the plates is:

Solution:


QUESTION: 21

A and B are inputs to a logic gate as shown in the figure.

For the given set of inputs and corresponding output data identify the logic gate.

Solution:

From the following truth table,
Y = A.B + A'.B'
Therefore this is an XNOR gate.

QUESTION: 22

A 220 V ac supply is connected between the two points A and B as shown in the figure. The output waveform (qualitative) across the diode is: 

Solution:


QUESTION: 23

Which of the following is correct when NPN transistor is used as an amplifier? 

Solution:

When NPN transistor is used as an amplifier, majority charge carrier electrons of N-type emitter move from emitter to base and then base to collector.

QUESTION: 24

Consider the statements given below:
1. At absolute zero temperature, an intrinsic semiconductor acts as an insulator.
2. The Fermi level in an intrinsic semiconductor lies between the valence band and conduction band.
Choose the correct statement(s).

Solution:

Both statements are correct.

QUESTION: 25

In a Zener regulated power supply, a Zener diode with Vz = 6.0 V , Iz = 5IL is used for regulation. The load current is to be 4.0 mA and the unregulated input is 10 V, as shown in the figure. The value of series resistance Rs required will be:

Solution:



QUESTION: 26

What happens when you heat china having some dark paintings engraved on it at 1000°C and then examine it in a dark room immediately?

Solution:

According to Kirchhoff’s law, if a body strongly absorbs radiation of a certain wavelength, it must emit strongly the radiation of the same wavelength. The dark paintings are better absorbers, and therefore, also better emitters.

QUESTION: 27

A spring-block system undergoes simple harmonic motion on a smooth horizontal surface. The block is now given some positive charge and a uniform horizontal electric field to the right is switched on, as a result:

Solution:


QUESTION: 28

The latent heat of vaporisation of water is more than latent heat of fusion of ice, because: 

Solution:

The latent heat of vaporisation of water is more than latent heat of fusion of ice because on vaporisation much large increase in volume takes place.

QUESTION: 29

The emissive power of a black body at T = 300 K is 100 W/m2. Consider a body B of area A = 10 m2, coefficient of reflectivity r = 0.3 and absorptivity a = 0.2. If its temperature is 300 K then mark out the correct statement.

Solution:



QUESTION: 30

For the indicator diagram given below, correct statement is: 

Solution:
  • It can be inferred from the figure that process 1 is anti-clockwise, therefore Wis negative. 
  • On the other hand, process 2 is clockwise and work done W2​ is positive.
  • As W1​ < W2​ and hence net work done for Wis positive.
QUESTION: 31

The light waves having displacements y1 = 10sin(ωt - kx) and y2 = 2sin(ωt - kx) interfere. The ratio of maximum to minimum average intensity of light in interference pattern is:

Solution:


QUESTION: 32

A parallel beam of monochromatic light of wavelength 600 nm passes through a long slit of width 0.4 mm. The angular divergence in which most of the light is diffracted is:

Solution:





QUESTION: 33

When a hydrogen atom, initially at rest emits a photon resulting n transition from n = 6 to n = 1, its recoil speed will be (mass of proton 1.6 x 10−27 kg):

Solution:

P = Momentum = mv

 

QUESTION: 34

For a plane electromagnetic wave, average of which among the following is zero:

Solution:
  • Both magnetic, as well as the electric field in EM waves, are sinusoidal in nature and we know that the average value of sinusoidal wave is zero.
  • Hence, both magnetic and electric fields have zero average value in a plane EM wave.
QUESTION: 35

When the air in a capacitor is replaced by a medium of dielectric constant K, the capacity ______ .                            

Solution:

Cmedium = K×Cair
So capacity increases K times.

 

QUESTION: 36

Binding energy per nucleon verses mass number curve for nuclei is indicated in the following figure. A, B, C and D are four nuclei indicated on the curve. Among the following, the process that would yield maximum energy is:
 

Solution:

Energy would be released when products of high BE/nucleon are produced.

QUESTION: 37

A charged beam consisting of electrons and positrons enter into a region of uniform magnetic field B perpendicular to field, with a speed v. The maximum separation between an electron and a proton will be? (mass of electron =  mass of proton = m)

Solution:

QUESTION: 38

Which of the following is true for Lyman series in hydrogen atom?

Solution:

The largest wavelength of Lyman series is 1215.7 Å.

QUESTION: 39

In a young’s double-slit experiment, the separation between the two slits is . The distance of the screen from the slits is 50 cm. If the wavelength of light used is 4000 Å, then the angular position of first dark fringe is: 

Solution:




QUESTION: 40

Snapshot of a transverse disturbance on a stretched string is shown in the following figure. The wave is travelling is along positive x-direction. The particles for which velocity is directed along negative y-direction is:

Solution:

QUESTION: 41

Which among the following has smallest wavelength?

Solution:

Among the given options, X-Rays has smallest wavelength.

QUESTION: 42

The amplifiers A, B and C are connected in series. If the voltage gain of A, B and C are 10, 15 and 20 respectively and input signal is 2 mV peak value. Then the output signal voltage’s peak value will be:

Solution:




QUESTION: 43

The heat absorbed by a system in going through a cyclic process shown in figure is:

Solution:


QUESTION: 44

The length of a metal wire is I1 when the tension in it is T1 and I2 when the tension in it is T2. The outstretched length of the wire is:

Solution:

QUESTION: 45

A body falls freely from rest for 4s. The average speed will be? (g = 10 m/s2

Solution:

QUESTION: 46

Which has the maximum number of molecules among the following?

Solution:


QUESTION: 47

The correct order of increasing energies of atomic orbitals in a multi electronic system is:

Solution:
  • The higher the value of (n+l) for an orbital the higher its energy. If two orbitals have the same value of (n+l) the orbital with the higher value of n will have higher energy.
  • The correct order of energy will be:
    3p < 4s < 3d < 4p
QUESTION: 48

Which of the following set of quantum numbers does not exist?

Solution:

The value of I can be 0 to (n-1). So the values of option C does not exist.

QUESTION: 49

For a first order reaction, the half-life period is 5 minutes. The time required for the concentration of the substance to fall from x M to  is:

Solution:


QUESTION: 50

The number of bond pairs and lone pairs of electrons around chlorine in CIF3 respectively are:

Solution:

QUESTION: 51

The bond order of O+2 is:

Solution:




QUESTION: 52

Equal masses of CH4 and O2 are mixed in a container at 25oC. The fraction of total pressure exerted by O2 is:

Solution:

Let the mass of O2 and CH4 be W gram each

QUESTION: 53

Average molar kinetic energies of O2 and SO2 at same temperature are related as: (K1 is the kinetic energy of O2 and K2 is the kinetic energy of SO2 at same temperature)

Solution:

Kinetic energy is a function of temperature only.

QUESTION: 54

Which of the following is not a path function?

Solution:

Enthalpy is a state function.

QUESTION: 55

The change in internal energy if 20J of heat is given to the system at constant pressure and 10J of work is done by the system is:

Solution:

QUESTION: 56

For a reaction H2 (g) + I→ 2HI (g), ΔH = 37.5 kJ/mol and ΔS = 150 JK-1 mol -1, the temperature at which the reaction will be:

Solution:


QUESTION: 57

For the reaction,  If the value of the equilibrium constant is K, then the equilibrium constant for this reaction is:

Solution:

If the reaction is reversed, the value of equilibrium constant is reciprocated. Also, if the reaction is multiplied by a factor (n) then the value of equilibrium constant becomes: 

QUESTION: 58

The conjugate acid of HCO3 is:

Solution:

QUESTION: 59

The solubility of a salt A2B in pure water will be: (Ksp of A2B = 1.08 x 10-16)

Solution:

QUESTION: 60

The oxidation state of Cr in CrO5 is:

Solution:

QUESTION: 61

Given the standard electron potentials,
Al3+/ Al = -1.66 V
K+/ K = - 2.93 V
Mg2+/ Mg = - 2.36 V
Cu2+/ Cu = 0.34 V
Zn2+/ Zn= -0.74 V
The correct order of these metals in their increasing order of reducing power is:

Solution:

Higher is the negative value of standard reduction potential, stronger is the reducing power.

QUESTION: 62

Which of the following is an electron precise hydride?

Solution:
  • NH3, HF and H2O are electron-rich hydrides. 
  • Whereas elements of group 14 form electron-precise hydrides (having the required number of electrons to write the Lewis structure). So CH4 is an electron precise hydride.
QUESTION: 63

Which among the following has the highest hydration enthalpy?

Solution:

The hydration enthalpy of alkali metals ions decreases with increase in ionic sizes.

QUESTION: 64

The chemical formula of washing soda is:

Solution:

QUESTION: 65

The correct order of ionisation enthalpy of group -13 elements is:

Solution:

QUESTION: 66

Neutral oxide among the following is:

Solution:

QUESTION: 67

The maximum boiling point among the following is of ______. 

Solution:

QUESTION: 68

In E1cB mechanism intermediate formed is ______.

Solution:

The first step in the E1cB mechanism is deprotonation (break C-H) to give a carbanion intermediate, and this step is promoted when there are electron-withdrawing groups adjacent to the alpha carbon (making the carbanion more stable).

QUESTION: 69

Catechol is:

Solution:

IUPAC name of Catechol is benzene-1,2-diol.

QUESTION: 70

Which among the following compound gives 1o-alcohol on reaction with Grignard reagent (RMgCI) followed by hydrolysis?

Solution:

QUESTION: 71

The major product (A) of the given reaction is:

Solution:

QUESTION: 72

Which of the following is not a use of zeolite(s) as catalyst(s)?

Solution:

QUESTION: 73

Which of the following is a polar molecular solid?

Solution:

QUESTION: 74

Which of the following is an incorrect match?

Solution:

ZnO is hexagonal.

QUESTION: 75

The electrode potentials for  are -0.04 V and -0.44 V respectively. The value of  will be:

Solution:


QUESTION: 76

The standard electrode potential of three metals A, B and C are -0.49 V, -0.28 V and +0.20 V respectively. The reducing power of these metals will be:

Solution:


The lower is Eoreduction, the higher is reducing power.

QUESTION: 77

An aqueous solution contains 0.5 molal Na2S. Which of the following changes will cause the vapour pressure of the solution to increase?

Solution:

Addition of less concentrated solution increases the mole fraction of water in an aqueous solution.

QUESTION: 78

At 25oC, the highest boiling point is shown by 0.01 molal solution of: (consider complete ionisation of electrolytes)

Solution:

QUESTION: 79

0.2 g of an organic compound gave 0.466 g of BaSO4. The % of sulphur in the compound is: (molecular mass of BaSo4=233u)

Solution:

QUESTION: 80

Which of the following alkane on monochlorination give only one product?

Solution:
QUESTION: 81

Sodium propionate on heating with soda lime gives ______.

Solution:

QUESTION: 82

Which among the following alkanes is/are liquid at 298 K?

Solution:

Alkane having 5 to 17 carbons are liquid at 298 K.

QUESTION: 83


Product P is:

Solution:

 When methane is combusted in the presence of Molybdenum oxide as catalyst, it yields methanal(HCHO) as product.

QUESTION: 84

Total number of conformers for ethane is:

Solution:
  • There are infinite conformers possible for ethane.
  • Conformational isomerism involves rotation about sigma bonds and does not involve any differences in the connectivity or geometry of bonding.
  • Although there are seven sigma bonds in the ethane molecule, rotation about the six carbon-hydrogen bonds does not result in any change in the shape of the molecule because the hydrogen atoms are essentially spherical.
  • Rotation about the carbon-carbon bond, however, results in infinite different possible molecular conformations.
QUESTION: 85

Which of the following dn configuration shows the strongest Jahn-Teller distortion for the octahedral complex?

Solution:

Jahn-teller distortion is applicable under the unsymmetric filling of eg level i.e. d7 (low spin complex).

QUESTION: 86

Which of the following will not give chromylchloride test?

Solution:

Covalent chloride like HgCI2 does not respond to the chromyl chloride test.

QUESTION: 87

Which of the following does not undergo Friedel-Crafts reaction?

Solution:

QUESTION: 88

Fe2​(CO)9  is diamagnetic. Which of the following reason is correct? 

Solution:

Metal-metal(Fe-Fe) bond pair up the unpaired electrons. Hence the correct option is (c).

QUESTION: 89

Which of the following statements is not correct?

Solution:

PMMA is an addition polymer. Poly(methyl methacrylate) (PMMA) is usually obtained by the addition polymerization of methyl methacrylate (MMA).

QUESTION: 90

Select the correct order of acidic strength of the following compounds:

Solution:
  • Ammonia is a base so it is having the least acidic strength.
  • Due to back bonding in the conjugate anion of CHCI3, it is more stable hence more acidic. Order of acidic strength: 
QUESTION: 91

Which of the following is not correct?

Solution:
  • The uterus consists of a body or corpus, a narrow uterine cavity and a lower cylindrical structure where the attachment of the developing foetus takes place known as implantation.
  • It takes place after 7 days of fertilisation (10-15 days in human).
QUESTION: 92

The largest flower found is known as ______.

Solution:
  • Rafflesia or Corpse flower is a total root parasite. It obtains the total nourishment from the root of the host plant.
  • Its flowers only come out of the host plant and they have a diameter of 1 m and weight around 10kg.
QUESTION: 93

The coconut water and the edible part of coconut are equivalent to:

Solution:

The edible white part of the coconut is known as endosperm (seed accumulates inside a pulp) that is equivalent to coconut water.

QUESTION: 94

Which of the following is true about protozoans?

Solution:

Protozoa (also protozoan, plural protozoans) is an informal term for a group of single-celled eukaryotes, either free-living or parasitic.

QUESTION: 95

The pollination of two flowers on different plants is known as ______.

Solution:

Fertilisation of a flower by pollen from a flower on a genetically different plant is called xenogamy.

QUESTION: 96

A plant tissue when stained showed the presence of hemicellulose and pectin in the cell walls of its cells. The tissue is called ______.

Solution:
  • Collenchyma is living mechanical tissue, found beneath the epidermis (i.e., hypodermis) of herbaceous dicot stem.
  • The intercellular spaces in this tissue are absent because in intercellular spaces at the corner of cells, thickenings of cellulose and pectin develop due to which the cell wall becomes rigid and thick at comers.
QUESTION: 97

The carrying capacity of a population is determined by ______.

Solution:

The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water, and other necessities available in the environment. 

QUESTION: 98

DNA duplication takes place in which of the following stage of cell cycle:

Solution:
  • There are 4 phases of the cell cycle, namely G1​ phase, S phase, G2​ phase and M phase.
  • During the G1​ phase or gap 1 phase, the cell increases in size. Also, various proteins are synthesized in this phase.
  • During the S phase or synthesis phase, DNA replication or duplication takes place.
  • During the G2​ phase, the cell continues to grow until it enters the M phase or mitosis phase. Cell division takes place in M phase. Thus, the correct answer is 'S'.
QUESTION: 99

The slime moulds and unicellular algae are presently included in the kingdom-Protista because:

Solution:

Slime moulds belong to the kingdom Protista where they appear to be more closely related to unicellular eukaryotes and does not follow the characteristic of fungi and other plants because they are algal and they do not follow other three kingdoms exclude Protista.

QUESTION: 100

Food in the sieve tube is transported in the form of ______.

Solution:
  • Phloem is a conducting tissue that transports food materials, usually from leaves to other parts of the plants.
  • In phloem, sieve elements transport sucrose. Starch is stored in tissues.
QUESTION: 101

Which of the following is assumed to be connecting link between plants and animals?

Solution:

Euglena contains characters of both plants and animals.

QUESTION: 102

Which of the following material is responsible for non-degradable nature of pollens? 

Solution:
  • Each pollen has a two-layered wall. The outer layer is thick, tough, cuticularised called exine which is composed of a material called “sporopollenin”.
  • It is highly resistant to biological and physical decomposition, due to which pollens are preserved for a long time in fossils.
QUESTION: 103

Which one of the following is caused by virus?

Solution:
  • Mumps is a viral infection that primarily affects saliva-producing (salivary) glands that are located near your ears. Mumps can cause swelling in one or both of these glands.
  • Measles is a highly contagious, serious disease caused by a virus.
  • Acquired immunodeficiency syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body's ability to fight infection and disease.
QUESTION: 104

Allosteric enzymes possess 

Solution:

Not all enzymes possess sites for allosteric binding; those that do are called allosteric enzymes. Allosteric enzymes typically comprise multiple protein subunits. When binding of an effector at one site on the enzyme alters the binding affinity at another site, the binding sites are said to be acting cooperatively.

QUESTION: 105

One of the following is true for Mandible:

Solution:

The mandible is the largest and strongest bone of the face that is called as lower jaw bone or jaw bone.

QUESTION: 106

In which one of the following habitats does the diurnal temperature of soil surface vary most?

Solution:
  • In the desert biome vegetation is scarce and the soil is sandy. The soil is exposed to the atmosphere because plant cover is missing.
  • During the day time, the sand becomes hot on exposure to sun rays and during the night after sunset, sand rapidly cools and loses heat fast.
  • Hence, the diurnal temperature of the soil surface varies most in deserts.
QUESTION: 107

Vegetative propagation in Chrysanthemum occurs by:

Solution:

Asexual or vegetative propagation of plants is that form of plant propagation in which the new individual arises from the parent by sucker, e.g, in lawn grass Cynodon (Doob grass); and Chrysanthemum.

QUESTION: 108

When secondary growth is initiated in dicot stem what will happen first?

Solution:

The parenchymatous cells present between vascular bundle dedifferentiate and become meristematic and form interfascicular cambium.

QUESTION: 109

Peripatus is a connecting link between:

Solution:

Peripatus is a soft-bodied worm-like, bilaterally symmetrical animal that is a living connecting link between arthropods and annelids.

QUESTION: 110

Match column-I with column-II and select the correct answer using the codes given below.

Solution:
QUESTION: 111

Which one of the following sets of animals share a four-chambered heart?

Solution:
  • Four chambered heart have a pulmonary circuit pathway (taking blood from heart to lung and back to heart).
  • Crocodiles, birds and mammals have four-chambered heart, birds have much larger heart compared to the mammal.
QUESTION: 112

Which of the following is correct set of micronutrient for plants?

Solution:
  • The essential elements are divided into macroelements and microelements based on the quantity in which they are required by the plants.
  • Mn, Fe, Cu, Mo, Zn, B, and Cl are the micronutrients needed in very small quantities by the plants.
  • C, H, O, N, P, S, K, Ca, Mg are the macronutrients required in more quantity.
QUESTION: 113

Which one of the following is the most suitable medium for culture of Drosophila melanogaster?

Solution:

Most suitable culturing media for Drosophila melanogaster is ripe banana which gives good results in the laboratories.

QUESTION: 114

Match the cell organelles given in column-I with cellular processes in column-II and select the correct option from the codes given below.

Solution:
QUESTION: 115

Which of the following set are all stop codon?

Solution:

Stop codons are UAG, UAA and UGA.

QUESTION: 116

Which one of the following pairs, is not correctly matched?

Solution:

Gibberellic acid stimulates cell growth of leaves and stem, causing their expansion, elongation respectively and leaf fall is controlled by ABA.

QUESTION: 117

Discontinuous synthesis of DNA occurs in one strand because:

Solution:

Discontinuous replication or synthesis of DNA molecule as a series of short fragments. Extension of RNA primers occurs by the addition of DNA dependent DNA polymerase catalyses.

QUESTION: 118

Zeatin is a type of: 

Solution:

Zeatin is a cytokinin present in maize.

QUESTION: 119

Bt gene, which produces protein toxic to insect larvae is:

Solution:

Cry genes encoded by the protein (toxin) are isolated from the bacterium and incorporated into several crop plants. Bt gene has maximum numbers of cry genes. 
Examples: cry I Ac, Cry II Ab, Cry I Ab etc.

QUESTION: 120

Pneumatophores are characteristic of plants growing in:

Solution:

Some plants growing in salty marshes develop special roots for respiration, called pneumatophores. They are negatively geotropic.

QUESTION: 121

Megasporangium is equivalent to:

Solution:
  • Megasporangium is female sporangia that produce megasporocytes that yield megaspores.
  • The ovule appears to be a megasporangium with integuments surrounding it.
QUESTION: 122

The reaction rate of salivary amylase on starch decreases as the concentration of chloride ions is reduced. Which of the following describes the role of the chloride ions?

Solution:

Many enzymes require a non-protein component for activity. These components are known as co-factors, which may be metal ions or organic in nature. The metal ions may be actually bound to the substrate rather than the enzyme.

QUESTION: 123

In pteridophytes, spores germinate to give rise to inconspicuous, small multicellular, free-living photosynthetic, thalloid gametophyte called ______.

Solution:

In pteridophytes, spores germinate to give rise to inconspicuous, small multicellular, free-living photosynthetic, thalloid gametophyte called “Prothallus”.

QUESTION: 124

PEP carboxylase is:

Solution:
  • Phosphoenolpyruvate carboxylase (PEPC) catalyzes the fixation of carbon dioxide with phosphoenolpyruvate to produce oxaloacetate and inorganic phosphate.
  • PEPC is found in most plants and bacteria.
QUESTION: 125

Which of the following statements is not true about genes that show 50% recombination frequency?

Solution:

Genetic linkage is the tendency of alleles that are close together. The recombination frequency will be 50% when two genes are located on different chromosomes that are tightly linked to each other.

QUESTION: 126

Which of the following statements are correct?
(i) Magnesium competes with iron and manganese for uptake and with iron for binding with enzymes.
(ii) Magnesium inhibit calcium translocation in shoot apex.
(iii) Excess of manganese may induce deficiencies of iron, magnesium and calcium.
(iv) Symptoms of manganese toxicity may actually be the deficiency symptoms of iron, magnesium and calcium.

Solution:

Manganese competes with iron and magnesium for uptake, and with magnesium for binding with enzymes. Manganese also inhibits calcium translocation in shoot apex.

QUESTION: 127

Bryophytes are called amphibians of the plant kingdom because:

Solution:
  • Bryophytes are called amphibians of the plant kingdom because these plants live in soil but they need water for sexual reproduction.
  • They are mostly found on marshy and wetlands where they can adapt to survive with both water nutrients and soil nutrients. So, bryophytes are called amphibians of the plant kingdom.
QUESTION: 128

Cry genes has been used in producing transgenic plants resistant to:

Solution:

Bt cotton is resistant to bollworm

QUESTION: 129

Which era could be called the ‘age of mammals and birds’?

Solution:

The Cenozoic Era is the most recent subdivision of other divisions. The Cenozoic Era describes the age of mammals including birds, while the Mesozoic era was the age of reptiles.

QUESTION: 130

Aqueous humour produced by the ciliary body is secreted into the posterior chamber and enters the anterior chamber through:

Solution:

The pupil permits the passage of light waves and the passage of aqueous humour.

QUESTION: 131

Which of the following is a dinoflagellate responsible for red tides?

Solution:
  • Gonyaulax is a genus of dinoflagellates with the type species Gonyaulax spinifera (Claparède et Lachmann) Diesing.
  • Gonyaulax belongs to red dinoflagellates and commonly causes red tides.
QUESTION: 132

The ‘Earth Summit’ held at Rio de Janerio in 1992 resulted in:

Solution:
  • The Earth Summit of Rio de Janeiro, also known as the United Nations Conference on Environment and Development (UNCED), was held in Rio de Janeiro from 3 to 14 June 1992.
  • It resulted in the Convention on Biodiversity, a multilateral treaty.
  • Three major goals were addressed in this convention which included:
    (i) conservation of biodiversity. 
    (ii) sustainable use of its components. 
    (iii) the fair and equitable sharing of benefits arising from the genetic resources.
QUESTION: 133

Papilionaceous corolla is a characteristic feature of:

Solution:
  • Papilionaceous corolla is characterised by butterfly-shaped because the petals are of different sizes and they show descending pattern of imbrication.
  • The largest posterior petal is called vexillum and it overlaps the lateral petals called wings. The wings overlap the innermost fused petals called keel or carina.
  • It is a characteristic of the family Fabaceae.
QUESTION: 134

Which of the following is true?
(i) ‘Operon hypothesis’ was proposed by Jacob and Monod.
(ii) ‘One gene-one enzyme theory’ was proposed by Beadle and Tatum.
(iii) ‘Southern blotting’ is used in DNA fingerprinting.
(iv) Uracil and Thymine bases remain present in DNA and RNA respectively.

Solution:

Thymine is found only in DNA, and Uracil is found only in RNA.

QUESTION: 135

In which of the following techniques, the embryos are transferred to assist those females who cannot conceive?

Solution:

ZIFT and IUT are the techniques in which embryos are transferred to assist those females who cannot conceive.

QUESTION: 136

Which one of the following statements about Mycoplasma is wrong?

Solution:
  • Mycoplasma is a single-celled, prokaryotic organism. The organism lacks the cell wall.
  • The antibiotic penicillin interferes with the process of cell wall synthesis in which the N-acetyl muramic acid, N-acetyl glucosamine and amino acids in peptidoglycan are linked.
  • The antibiotic interferes with the process of linking of these molecules in the cell wall.
  • Since there is no cell wall in the Mycoplasma, there is no effect of penicillin.
QUESTION: 137

If a colourblind woman marries a normal visioned man, their sons will be:

Solution:

When a colour blind woman marries a normal visioned male, daughters will be carrier for this disease and all sons will be colour blind, this can be represented as follows:

QUESTION: 138

Prior to mutation, a sequence of DNA reads GAGCCTATGCCAGTA. After the mutation, the sequence reads GAGCGTACGCCATTA. Which of the following best explains the change in DNA that has occurred?

Solution:
  • Since the total number of bases is the same, either no deletions or insertions occurred, or an equal number of each must have occurred.
  • In this case, however, simply comparing each strand base for base shows that the multiple substitutions took place along the sequence.
QUESTION: 139

Ligament is present between:  

Solution:
  • A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as articular ligament, articular larua, fibrous ligament, or true ligament.
  • Other ligaments in the body include the Peritoneal ligament: a fold of peritoneum or other membranes.
QUESTION: 140

Which of the following is a large middle layer consisting of the main uterine gland as well as blood vessels?

Solution:
  • The stratum spongiosum is the large middle layer.
  • It contains the main portions of uterine glands and accompanying blood vessels; the stromal cells are more loosely arranged and larger than in the stratum compactum.
QUESTION: 141

Which of the following crops is being grown in India for biodiesel?

Solution:

Jatropha Curcas, generated interest as an oil crop for biodiesel production in India.

QUESTION: 142

Which one of the following is correct match?

Solution:

Morphine is an opiate narcotic, Bhang is a hallucinogen, Reserpine derived from Raimolffia, is used as a tranquiliser, cocaine is a stimulant.

QUESTION: 143

Cell theory was proposed by Schleiden and Schwann. Which of the following is an exception for cell theory?

Solution:

Cell theory states that all living cells are made of cells that, are the fundamental unit of life but viruses are not made up of cells. But it is considered to be living. Therefore it is an exception of the theory.

QUESTION: 144

The site where lymphocytes mature is:

Solution:

B cells mature in the bone marrow and T cells mature in the thymus.

QUESTION: 145

In accordance with the Human Genome Project, select the incorrect statement.

Solution:
  • The Human Genome Project goal was of determining the sequence of chemical base pair.
  • Two major approaches involved i.e; ESTs and SNPs in human.
  • This project was launched in 1990 and finally declared complete in 2003.
QUESTION: 146

The technique called Gamete Intrafallopian Transfer (GIFT) is recommended for those females:

Solution:
  • Gamete intrafallopian transfer (GIFT) is recommended for those females who cannot produce an ovum.
  • In this process, the eggs of the donor woman are removed and in a form of a mixture with sperm transferred into the fallopian tube of another woman who cannot produce ovum, but can provide a suitable environment for fertilisation.
  • Thus in GIFT, the site of fertilisation is the fallopian tube, not the laboratory.
QUESTION: 147

A marine cartilaginous fish that can produce electric current is:

Solution:

Torpedo is a marine cartilaginous fish that produces an electric current for protection or self-defence.

QUESTION: 148

Which of the following statement(s) is/are correct regarding class aves?
(i) The forelimbs are modified into wings and the hindlimbs generally have scales and are modified for walking, swimming or clasping the tree branches.
(ii) Heart is completely four-chambered.
(iii) They are warm-blooded (homoiothermic) animals i.e., they are able to maintain constant body temperature.
(iv) They are oviparous and development is direct.

Solution:
QUESTION: 149

Which one of the following is the thickest part of the mammalian heart?

Solution:

The myocardium is the thick, middle layer of the heart and is composed of cardiac muscle.

QUESTION: 150

If you examine the reproductive system of a normal human female before she undergoes puberty, which of the following would you not expect to find?

Solution:

Corpus luteum is formed after ovulation only.

QUESTION: 151

Which of the following bonds are found in DNA?

Solution:

Glycosidic bond is present between Pentose sugar and N-base, and phosphodiester bond is found between nucleotides. So both bonds are found in DNA.

QUESTION: 152

Coronary artery disease (CAD) is often referred to as:

Solution:
  • Coronary artery disease (CAD) is often referred to as Atherosclerosis.
  • It is caused by the narrowing of the large blood vessels that supply the heart with oxygen. These are called coronary arteries.
QUESTION: 153

Pteridophytes were well adapted and advanced in survival on land but they cannot be much successful and widespread as gymnosperms and angiospermic plants because they lack:

Solution:

Pteridophytes lack freedom from water for fertilisation. Therefore they cannot get much success as gymnosperms and angiosperms.

QUESTION: 154

Which one of the following is a matching pair of a substrate and its particular digestive enzyme?

Solution:
  • Intestinal juices contain a number of oligasaccharidase which hydrolyse the specific oligosaccharides into their monosaccharides.
  • Maltase is one of them, which hydrolyses maltose into two glucose molecules.
QUESTION: 155

Most of the fat digestion occurs in:

Solution:

The small intestine is a principal organ for the absorption of nutrients and completes the digestion where the final products of digestion are glucose, fructose, fatty acids, glycerol and amino acids are absorbed through the mucosa into the bloodstream and lymph.

QUESTION: 156

The bulk of carbon dioxide (CO2) released from body tissues into the blood is present as:

Solution:
  • Some of the carbon dioxide is transported dissolved in the plasma. Some carbon dioxide is transported as carbaminohemoglobin.
  • However, most carbon dioxide is transported as bicarbonate. As blood flows through the tissues, carbon dioxide diffuses into red blood cells, where it is converted into bicarbonate.
QUESTION: 157

Which one of these is an in-situ method of conservation?

Solution:
  • In-situ conservation is the conservation of living resources within the natural ecosystems.
  • It includes a comprehensive system of protected areas such as National parks, sanctuaries, Natural reserves, cultural landscapes etc.
QUESTION: 158

Find out the correct order of succession levels in Xerarch.

Solution:

Xeric succession commonly occurs on bare rock surfaces (Lithosere) resulting from glaciation or from erosion by wind and water.

QUESTION: 159

The values of osmotic potential (π) and pressure potential (P) of cells A, B, C and D are given below.

Identify the correct sequence that shows the path of movement of water from among the following.

Solution:

The values of osmotic potential (π) is double the values of pressure potential (ρ) of cells. In the path of water movement, it shows ascending values as B → D → A → C

QUESTION: 160

Genetic drift is the change of:

Solution:
  • Genetic drift is also known as the Sewall Wright effect.
  • It refers to the random changes in gene frequencies in a population by chance, either due to intensive inbreeding or the death of a small section of the population by natural calamity.
  • Its effect is more marked in a small isolated population.
QUESTION: 161

Endemic goitre is a state of:

Solution:

Endemic goitre is associated with dietary iodine deficiency causes swelling in the frontal part of the neck or endemic goitre occurs when the prevalence of thyroid enlargement in which thyroid gland decrease their function to the stimulation of hormone.

QUESTION: 162

Which variety of rice caused the green revolution in India?