118 MCQs from MDCAT 2016 in our bank, each with its correct answer and a solution. This is a recall-based collection gathered from students and past-paper books, not the complete official paper.
1.All viruses can reproduce within living organisms only, so they are known as: (UHS MDCAT 2016)
Correct answer: (c) Obligative Intracellular Parasites
A virus can multiply only inside a living cell, so it is an obligate intracellular parasite.
2.AIDS is caused by: (UHS MDCAT 2016)
Correct answer: (b) Virus
AIDS is caused by the human immunodeficiency virus.
3.In a laboratory experiment when an unknown compound was added in a test tube containing iodine, the colour became intense blue. What could be the unknown compound? (UHS MDCAT 2016)
Correct answer: (d) Starch
Starch gives the deep blue colour with iodine.
4.The compounds which on hydrolysis yield polyhydroxy aldehyde or ketone subunits are: (UHS MDCAT 2016)
Correct answer: (d) Carbohydrates
A carbohydrate hydrolyses to polyhydroxy aldehydes or ketones, that is to simple sugars.
5.Secondary structure of protein is found in: (UHS MDCAT 2016)
Correct answer: (b) Keratin
Keratin is a fibrous protein whose chains are held in the alpha helix, its secondary structure.
6.Waxes are formed by combination of fatty acids with: (UHS MDCAT 2016)
Correct answer: (a) Alcohol
A wax is the ester of a fatty acid with a long chain alcohol.
7.Which one of the following nitrogen base is NOT present in DNA? (UHS MDCAT 2016)
Correct answer: (c) Uracil
Uracil belongs to RNA; DNA carries thymine.
8.Phosphodiester bond is: (UHS MDCAT 2016)
Correct answer: (c) C—O—P—O—C
A phosphate joins the third carbon of one sugar to the fifth carbon of the next.
9.The rapid exchange of materials through carrier proteins across the plasma membrane is called: (UHS MDCAT 2016)
Correct answer: (d) Facilitated Diffusion
A carrier protein passes the molecule down its gradient without cost, which is facilitated diffusion.
10.The basic structure of plasma membrane is provided by: (UHS MDCAT 2016)
Correct answer: (d) Phospholipids
The phospholipid bilayer is the framework into which everything else is set.
11.Out of the given options, choose the one which shows the structures found only in plants (UHS MDCAT 2016)
Correct answer: (c) Chloroplast, Cell Wall, Vacuole
A chloroplast, a cellulose wall and a large central vacuole are found in plant cells alone.
12.Presence of large central vacuole is the characteristic of: (UHS MDCAT 2016)
Correct answer: (d) Plants
A large central vacuole holding cell sap is a mark of the plant cell.
13.Many bacteria are motile due to presence of: (UHS MDCAT 2016)
Correct answer: (a) Flagella
Bacteria swim by rotating their flagella.
14._________ is an invagination of cell membrane which helps in cell division. (UHS MDCAT 2016)
Correct answer: (c) Mesosome
A mesosome is an infolding of the bacterial membrane to which the chromosome is anchored.
15.Which one of the following organelle is found in both prokaryotic and eukaryotic cells? (UHS MDCAT 2016)
Correct answer: (d) Ribosome
Every cell makes protein on ribosomes, though the prokaryotic ones are smaller.
16.The inner membrane of mitochondria form extensive infoldings called: (UHS MDCAT 2016)
Correct answer: (a) Cristae
The infoldings of the inner mitochondrial membrane are the cristae.
17.The organelle involved in detoxification of drugs and poisons in the liver cells is: (UHS MDCAT 2016)
Correct answer: (a) Smooth Endoplasmic Reticulum
The smooth endoplasmic reticulum of the liver carries the enzymes that break down drugs.
18.Which of the following is an example of autosomal non-disjunction? (UHS MDCAT 2016)
Correct answer: (d) Down’s syndrome
Down syndrome is an extra chromosome 21, an autosome that failed to separate.
19.Down’s syndrome is characterized by _____________ at chromosome 21. (UHS MDCAT 2016)
Correct answer: (a) Trisomy
Down syndrome is three copies of chromosome 21.
20.Infertility, short height, webbed neck and low hairline at lack are symptoms of _____________ syndrome. (UHS MDCAT 2016)
Correct answer: (a) Turner’s
Turner syndrome is a single X chromosome with no partner.
21.Part of hind brain responsible for the balance and equilibrium of body is called: (UHS MDCAT 2016)
Correct answer: (b) Cerebellum
The cerebellum of the hindbrain keeps balance and coordinates movement.
22.An enzyme required Mg2+ to catalyze the substrate. The Mg2+ is best identified as: (UHS MDCAT 2016)
Correct answer: (b) Activator
A metal ion needed for activity is an activator, or cofactor.
23.According to _________ model the active site of enzyme is modified as the substrate interacts with enzyme. (UHS MDCAT 2016)
Correct answer: (a) Induced fit
In the induced fit model the active site is moulded round the substrate.
24.The total number of genes in a population is called: (UHS MDCAT 2016)
Correct answer: (a) Gene pool
All the alleles of all the genes in a population make its gene pool.
25.Structures found in different species which are believed to have a common evolutionary origin are called: (UHS MDCAT 2016)
Correct answer: (a) Homologous
Structures of common ancestry are homologous, whatever work they now do.
26.Which one of the following is considered as strong evidence of evolution? (UHS MDCAT 2016)
Correct answer: (d) Fossil Record
The fossil record is the direct evidence of what lived and in what order.
27.Events of menstrual cycle are regulated by the: (UHS MDCAT 2016)
Correct answer: (b) Gonadotrophins
The gonadotrophins FSH and LH from the pituitary drive the cycle.
28.Decrease of FSH and increase of estrogen cause pituitary gland to secrete: (UHS MDCAT 2016)
Correct answer: (b) Luteinizing Hormone
As FSH falls and oestrogen rises, the pituitary answers with the surge of luteinizing hormone.
29.Transmission of Neisseria gonorrhea is best described by which one of the following? (UHS MDCAT 2016)
Correct answer: (b) Unsafe Sex
Gonorrhoea is passed by sexual contact.
30.Longest bone in the human skeleton is: (UHS MDCAT 2016)
Correct answer: (d) Femur
The femur, the thigh bone, is the longest bone in the body.
31.In pelvic region of human body, sacrum is formed by the fusion of: (UHS MDCAT 2016)
Correct answer: (b) 5 Vertebrae
Five sacral vertebrae fuse into the sacrum.
32.Brain is protected and enclosed in: (UHS MDCAT 2016)
Correct answer: (d) Cranium
The cranium of the skull encloses the brain.
33.Each muscle fibre is surrounded by a modified cell membrance called: (UHS MDCAT 2016)
Correct answer: (a) Sarcolemma
The membrane of a muscle fibre is the sarcolemma.
34.Hips and shoulder joints are examples of: (UHS MDCAT 2016)
Correct answer: (b) Ball and Socket Joints
Both are ball and socket joints.
35.A character determined by three alleles is: (UHS MDCAT 2016)
Correct answer: (b) Human blood group
The ABO system has three alleles, of which each person carries two.
36.Which one of the following is X-linked trait? (UHS MDCAT 2016)
Correct answer: (c) Haemophilia
Haemophilia is carried on the X chromosome.
37.In human the closed sac which surrounds the heart is: (UHS MDCAT 2016)
Correct answer: (c) Pericardium
The pericardium is the double sac round the heart.
38.Chordae tendinea are fibrous cords attached with: (UHS MDCAT 2016)
Correct answer: (b) Tricuspid valve of heart
The chordae tendineae hold the cusps of the atrioventricular valves against the pressure of systole.
39.To combat the active infections of tetanus, rabies and snakes the _______ method of immunization is used: (UHS MDCAT 2016)
Correct answer: (d) Passive
Ready made antitoxin is injected, so the immunity is passive and acts at once.
40.The type of immunity in which antibodies are passed from one individual to another is called: (UHS MDCAT 2016)
Correct answer: (a) Passive Immunity
Antibodies received ready made give passive immunity.
41.Variable amino acid sequences in antibody molecule are found in ________. (UHS MDCAT 2016)
Correct answer: (d) Both heavy and light chains
Both the heavy and the light chains have a variable region, and together they make the binding site.
42.B-cells release antibodies in blood plasma, tissue fluid and lymph. This kind of immune response is called: (UHS MDCAT 2016)
Correct answer: (b) Humoral Response
Immunity carried by antibodies in the body fluids is the humoral response.
43.In antibody molecule, two heavy and two light chains are bonded by: (UHS MDCAT 2016)
Correct answer: (a) Disulphide Bond
The four chains of an antibody are held by disulphide bridges.
44.Breathing consists of: (UHS MDCAT 2016)
Correct answer: (d) Two phases
Breathing has two phases, inspiration and expiration.
45.Carboxyhaemoglobin (10-20%) is formed when CO2 combines with: (UHS MDCAT 2016)
Correct answer: (a) Amino group of haemoglobin
Carbon dioxide combines with the terminal amino groups of the globin chains.
46.___________ are the part of a gastric gland which produce hydrochloric acid. (UHS MDCAT 2016)
Correct answer: (a) Parietal Cells
The parietal, or oxyntic, cells make the hydrochloric acid.
47.Digestive System consists of different layers, the innermost is known as: (UHS MDCAT 2016)
Correct answer: (b) Mucosa
The mucosa lines the lumen; the submucosa, muscularis and serosa lie outside it.
48.Protein components of food are digested by the enzymatic secretion of: (UHS MDCAT 2016)
Correct answer: (c) Zymogen Cells
The zymogen, or chief, cells make pepsinogen.
49.Food enters from stomach into small intestine through: (UHS MDCAT 2016)
Correct answer: (a) Pyloric Sphincter
The pyloric sphincter lets the chyme through into the duodenum a little at a time.
50.Digestion of __________ starts in oral cavity due to the action of enzyme present in saliva. (UHS MDCAT 2016)
Correct answer: (a) Starch
Salivary amylase begins the digestion of starch in the mouth.
51.Bowman’s capsule continues as extensively convoluted portion known as: (UHS MDCAT 2016)
Correct answer: (b) Proximal convoluted tubules
The Bowman capsule leads into the proximal convoluted tubule.
52.A hormone released from posterior pituitary lobe acts to be actively transport water from filtrate is collecting tubules back to kidney is shown as: (UHS MDCAT 2016)
Correct answer: (b) Antidiuretic hormone
Antidiuretic hormone makes the collecting duct permeable, so water returns to the blood.
53.Humans have homeostatic thermostat present in a specified portion of the brain that is: (UHS MDCAT 2016)
Correct answer: (d) Hypothalamus
The hypothalamus holds the thermostat of the body.
54.Highly toxic nitrogenous excretory product is: (UHS MDCAT 2016)
Correct answer: (d) Ammonia
Ammonia is very toxic, which is why it must be either diluted greatly or converted to urea.
55.The removal metabolic waste from the blood is called: (UHS MDCAT 2016)
Correct answer: (d) Excretion
Removing the waste of metabolism from the blood is excretion.
56.Restriction endonucleases cleave the __________ of duplex DNA. (UHS MDCAT 2016)
Correct answer: (c) Phosphodiester bond
A restriction enzyme cuts the sugar phosphate backbone at a specific sequence.
57.The enzyme which is responsible for the formation of bond between two double stranded DNA fragments is: (UHS MDCAT 2016)
Correct answer: (c) Ligase
DNA ligase seals the backbone between two fragments.
58.The modified plasmid or phage DNA is called: (UHS MDCAT 2016)
Correct answer: (b) Recombinant DNA
A plasmid carrying an inserted gene is recombinant DNA.
59.What mass of NaOH is present in 0.5 mol of sodium hydroxide? (UHS MDCAT 2016)
Correct answer: (d) 20 gm
$0.5\times40$ is $20\,\mathrm{g}$.
60.The number of moles of CO2 which contain 8.00 gm of oxygen is: (UHS MDCAT 2016)
Correct answer: (c) 0.25
$8.00\,\mathrm{g}$ is half a mole of oxygen atoms, and each molecule carries two.
61.The substance for the separation of isotopes is firstly converted into the (UHS MDCAT 2016)
Correct answer: (c) Vapour state
Isotopes are separated in a mass spectrometer, which works on the vapour.
62.Number of neutrons in 6630Zn (UHS MDCAT 2016)
Correct answer: (d) 36
$66-30$ leaves $36$ neutrons.
63.The maximum number of electrons in electronic configuration can be calculated by using formula: (UHS MDCAT 2016)
Correct answer: (c) 2n2
A shell holds $2n^2$ electrons.
64.Which element of 3d series of periodic table shows the electronic configuration of 3d8, 4s2? (UHS MDCAT 2016)
Correct answer: (d) Ni
$[\mathrm{Ar}]3d^8 4s^2$ accounts for 28 electrons, which is nickel.
65.London dispersion forces are the only forces present among the ____. (UHS MDCAT 2016)
Correct answer: (d) Molecules of solid chlorine
Chlorine is non-polar, so only instantaneous dipoles hold its molecules in the solid.
66.Freezing point will also be defined as that temperature at which its solid and liquid phases have the same: (UHS MDCAT 2016)
Correct answer: (c) Vapour pressure
At the freezing point the solid and the liquid are in equilibrium, so their vapour pressures are equal.
67.Electrical conductivity of graphite is greater in one direction that in other due to (UHS MDCAT 2016)
Correct answer: (c) Anisotropy
Graphite conducts along its layers but not across them, which is anisotropy.
68.Value of Ksp for PbSO4 system at 25 °C is equal to: (UHS MDCAT 2016)
Correct answer: (c) 1.6 x 10-8mol2dm-6
The solubility product of lead sulphate at $25^{\circ}\mathrm{C}$ is about $1.6\times10^{-8}$.
69.Human blood maintains its pH between (UHS MDCAT 2016)
Correct answer: (d) 7.35 – 7.40
Blood is buffered between about pH $7.35$ and $7.45$.
70.The rate constant ‘k’ is 0.693 min-1. The half-life for the 1st order reaction will be: (UHS MDCAT 2016)
Correct answer: (a) 1 min
$t_{1/2}=0.693/k=0.693/0.693$, that is one minute.
71.The average bond energy of C-Br is (UHS MDCAT 2016)
Correct answer: (d) 290 kJmol-1
The carbon bromine bond energy is about $290\,\mathrm{kJ\,mol^{-1}}$.
72.The ionic radius of fluoride ion is: (UHS MDCAT 2016)
Correct answer: (c) 136 pm
The fluoride ion is much larger than the atom, about $136\,\mathrm{pm}$.
73.2NaOH(aq) + Cl2(g) → NaCl + NaClO + H2O proceed at: (UHS MDCAT 2016)
Correct answer: (d) 15 °C
Cold dilute alkali gives the chloride and the hypochlorite; hot concentrated alkali would give the chlorate.
74.Melting points of group II-A elements are higher than those of group I-A because: (UHS MDCAT 2016)
Correct answer: (c) Atoms of II-A elements provide two binding electrons
Each group II atom contributes two electrons to the metallic bond instead of one.
75.The anomalous electronic configuration shown by chromium and copper among 3-d series of elements is due to: (UHS MDCAT 2016)
Correct answer: (c) Stability associated with this configuration
A half filled or filled d subshell is unusually stable, so an s electron moves across.
76.Which one of the following pairs can be cis-trans isomer to each other? (UHS MDCAT 2016)
Correct answer: (c) CH3CH=CHCH3 and H3CCH=CHCH3
But-2-ene has a methyl and a hydrogen on each carbon of the double bond, so cis and trans differ.
77.. Which one of the following is NOT a nucleophile: (UHS MDCAT 2016)
Correct answer: (c) BF3
Boron trifluoride has an empty orbital and accepts a pair, so it is an electrophile.
78.Which one of the following reactions shows combustion of a saturated hydrocarbon? (UHS MDCAT 2016)
Correct answer: (b) CH4 + 2O2 → CO2 + 2H2O
Methane is the saturated one, and it burns to carbon dioxide and water.
79.Which one of the following is an appropriate indication of positive iodoform test? (UHS MDCAT 2016)
Correct answer: (d) Yellow crystal
Iodoform comes down as yellow crystals with the smell of antiseptic.
80.Which one of the following reaction of carboxylic acid is reversible? (UHS MDCAT 2016)
Correct answer: (a) Esterification
Esterification is an equilibrium, which is why the water is removed to drive it forward.
81.When acid is added to an amino acid, which one of the following will act as a base? (UHS MDCAT 2016)
Correct answer: (b) COO-
The carboxylate group of the zwitterion takes the added proton.
82.Which one of the following is simplest amino acid? (UHS MDCAT 2016)
Correct answer: (d) Glycine
Glycine has a single hydrogen atom for its side chain.
83.In the formation of Zwitter ion which one of the following donates the proton? (UHS MDCAT 2016)
Correct answer: (a) COOH
The carboxyl group gives its proton to the amino group, and the ion carries both charges.
84.Which one of the following polymer is called as Nylon 6,6? (UHS MDCAT 2016)
Correct answer: (c) Polyamide
Nylon-6,6 is a polyamide made from a diamine and a diacid.
85.If we double the moment arm the value of torque becomes: (UHS MDCAT 2016)
Correct answer: (c) Two-times
Torque is force times moment arm, so twice the arm is twice the torque.
86.A man in elevator ascending with an acceleration will conclude that his weight is: (UHS MDCAT 2016)
Correct answer: (a) Increased
The floor must push up with $m(g+a)$, and that is what the man feels as his weight.
87.When fluid is incompressible, the quantity is constant is: (UHS MDCAT 2016)
Correct answer: (b) Density
An incompressible fluid is one whose density does not change however it is squeezed.
88.In Bernoulli’s equation the term 1/2 ρv2 is called: (UHS MDCAT 2016)
Correct answer: (a) K.E. per unit volume
Each term of Bernoulli’s equation is an energy per unit volume, and this one is the kinetic part.
89.Potential energy per unit volume is given by: (UHS MDCAT 2016)
Correct answer: (d) ρgh
$mgh$ divided by the volume gives $\rho gh$.
90.Frequency audible range to human hearing lies in the range: (UHS MDCAT 2016)
Correct answer: (c) 20-20000 Hz
The human ear hears from about $20\,\mathrm{Hz}$ to $20\,\mathrm{kHz}$.
91.Resonance occurs when the driving frequency is: (UHS MDCAT 2016)
Correct answer: (d) Equal to the natural frequency
Resonance comes when the driving frequency matches a natural frequency of the body.
92.The relation ‘PV = nRT’ shows which law of physics: (UHS MDCAT 2016)
Correct answer: (d) Ideal Gas Law
$PV=nRT$ is the ideal gas equation.
93.The relation R/NA = 1.38 x 10-25 JK-1 in a gas law is known as: (UHS MDCAT 2016)
Correct answer: (d) Boltzmann’s constant
The gas constant per molecule is Boltzmann’s constant.
94.The rapid escape of air from a burst tyre is an example of: (UHS MDCAT 2016)
Correct answer: (a) Adiabatic processes
The air escapes far too fast for any heat to be exchanged.
95.Which relation exactly described the isothermal process? (UHS MDCAT 2016)
Correct answer: (a) Q = W
The temperature is held, so the internal energy does not change and all the heat goes into work.
96.If a turbine is working as a heat engine and takes that from hot body (427 °C) and exhausts into a body at 77 °C then what is the possible efficiency? (UHS MDCAT 2016)
Correct answer: (a) 50%
$1-T_c/T_h=1-350/700$, that is $50\%$.
97.If the length, width and separation between the plates of a parallel plate capacitor is doubled then its capacitance becomes: (UHS MDCAT 2016)
Correct answer: (a) Double
$C=\varepsilon A/d$: four times the area over twice the separation is twice the capacitance.
98.The unit for electric charge is Coulomb and one Coulomb in terms of base unit is equivalent to: (UHS MDCAT 2016)
Correct answer: (c) As
A coulomb is an ampere second.
99.Resistance between two opposite faces of square thin film of area 1 mm2 having thickness of 1 μm if resistivity of material is 10-6 Ω will be: (UHS MDCAT 2016)
Correct answer: (c) 1 Ω
$R=\rho L/A=10^{-6}\times10^{-3}/(10^{-3}\times10^{-6})$, that is $1\,\Omega$.
100.The force acting on current carrying conductor will be maximum if the angle between magnetic field and conductor is: (UHS MDCAT 2016)
Correct answer: (c) 90°
$F=BIL\sin\theta$ is greatest when the conductor lies across the field.
101.‘F’ is maximum force acting on a conductor. Now if we change the direction of conductor by making an angle of 45° with the magnetic field then the force becomes: (UHS MDCAT 2016)
Correct answer: (c) F/√2
$F=BIL\sin45^{\circ}$, and the sine of $45^{\circ}$ is $1/\sqrt2$.
102.If we doubled all the parameters of the force acting on current carrying conductor and θ = 90° then magnetic force becomes: (UHS MDCAT 2016)
Correct answer: (c) Eight-times
$F=BIL$, and doubling each of the three multiplies the force by eight.
103.Tuning a radio is a best example of: (UHS MDCAT 2016)
Correct answer: (d) Electrical resonance
A radio is tuned by matching the natural frequency of its circuit to that of the station.
104.The continuous spectrum of X-ray is formed due to: (UHS MDCAT 2016)
Correct answer: (b) Bremsstrahlung X-ray
Electrons braked by the target give up energy in any amount, so the background is continuous.
105.The shadow of the bones in X-rays photographic film appears lighter than the surrounding flesh due to: (UHS MDCAT 2016)
Correct answer: (c) Bones absorb greater amount of X-rays
Bone contains calcium and absorbs the X-rays strongly, so less reaches the film behind it.
106.Wavelength of γ-rays is: (UHS MDCAT 2016)
Correct answer: (c) Shorter to the X-rays
Gamma rays come from the nucleus and carry more energy still, so their wavelength is the shorter.
107.The target of X-ray tube is made up of which metal? (UHS MDCAT 2016)
Correct answer: (d) Tungsten
Tungsten is used because it is dense and stands the heat.
108.The X-rays consists of: (UHS MDCAT 2016)
Correct answer: (d) High energy photons
X-rays are electromagnetic radiation, that is photons of high energy.
109.Thorium is transformed after the transmission of β-particle into: (UHS MDCAT 2016)
Correct answer: (b) Protactinium
Beta emission raises the atomic number by one, taking thorium to protactinium.
110.Emission of γ-rays from radioactive element results into: (UHS MDCAT 2016)
Correct answer: (c) Polonium
Gamma emission changes neither the mass number nor the atomic number, so the element is unchanged in kind.
111.The relation between decay constant ‘λ’ and half-life ‘T½’ of radioactive substance is: (UHS MDCAT 2016)
Correct answer: (d) λ = 0.693/T1/2
$\lambda=0.693/t_{1/2}$.
112.Sodium-24 is used for: (UHS MDCAT 2016)
Correct answer: (b) Study of circulation of blood
Sodium-24 is injected as common salt and followed with a counter to trace the circulation.
113.Radioisotope which is used to combat cancer of thyroid gland is: (UHS MDCAT 2016)
Correct answer: (a) Iodine-131
Iodine-131 gathers in the thyroid and irradiates it from within.
114.Energy radiation absorbed at the rate of one joule per kilogram is called: (UHS MDCAT 2016)
Correct answer: (d) 1 Gray
One gray is one joule absorbed in each kilogram.
115.The assassination of the president __________ the country into war. (UHS MDCAT 2016)
Correct answer: (d) Precipitated
To precipitate an event is to bring it on suddenly.
116.His theories have been __________ by recent research. (UHS MDCAT 2016)
Correct answer: (d) Debunked
To debunk a theory is to show it up as false.
117.She might be forgiven for __________ beneath the pressure. (UHS MDCAT 2016)
Correct answer: (c) Buckling
To buckle under pressure is to give way beneath it.
118.International rules __________ the number of foreign entrants. (UHS MDCAT 2016)
Correct answer: (b) Stipulate
To stipulate is to lay down as a condition.