Pakistan Medical Commission (national paper)
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If during circular motion, tangential velocity of a body becomes double then centripetal force becomes:
Explanation
Centripetal force varies as v^2 (Fc = mv^2/r). Doubling the tangential speed multiplies Fc by 2^2 = 4, so the force becomes four times. Answers like 'double' or 'one half' ignore the square dependence on velocity.
Under what condition an object will have zero displacement but non zero distance?
Explanation
In circular motion, after one full revolution the object returns to its starting point so displacement (vector from start to end) is zero while the distance travelled is the circumference (non-zero). Linear or random motion need not return to the start.
Which one of the following properties is not exhibited by the longitudinal waves?
Explanation
Polarization is a property of transverse waves (it involves orientation of oscillations). Longitudinal waves (oscillations parallel to propagation) can show interference, reflection and diffraction but not polarization.
The speed of sound in air is 332m/s. the speed of sound at 22oC will be:
Explanation
Speed of sound in air increases roughly by 0.6 m/s per °C from 0°C; V = 332 + 0.6×22 = 332 + 13.2 = 345.2 m/s. This gives option 345.2 m/s.
Astronomers calculate speed of dstant stars and galaxies using which of the following phenomena?
Explanation
The Doppler effect shifts spectral lines depending on radial velocity of astronomical objects; this shift is used to measure their speed. Beats and basic interference are not used for large-scale radial velocity measurements.
In a ripple tank, 40 waves pass through a certain point in 1 second. If the wavelength of the wave is 5 cm, then speed of the wave is:
Explanation
Wave speed v = fλ. Here f = 40 s⁻1 and λ = 0.05 m, so v = 40×0.05 = 2 m/s. The other choices are obtained from incorrect arithmetic or unit conversion.
In which process the entire of heat supplie to the gas is converted to the internal energy of the gas?
Explanation
In an isochoric (constant-volume) process no work is done (ΔV = 0), so any heat supplied changes only internal energy (ΔQ = ΔU). In isothermal ΔU = 0, and in adiabatic ΔQ = 0.
The internal energy of a system during an isothermal process:
Explanation
For an ideal gas in an isothermal process the temperature is constant, and internal energy depends only on temperature, so internal energy remains constant. It neither increases nor decreases.
If the potential at a point which is 1m from a charge is 1 volt, them the potential at a pont which is 2m from the same charge will be:
Explanation
Electric potential V due to point charge varies as 1/r (V = kQ/r). Doubling the distance halves the potential, so 1 V → 0.5 V at 2 m.
The values of electric intensity will due to the presence of dielectric medium:
Explanation
A dielectric reduces the effective electric field (electric intensity) within a capacitor for the same free charge because bound charges oppose the field; thus the field/PD is reduced if charge is held constant.
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The slope of distance – time graph will always be:
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If we drop an object, its initial velocity is zero. How far will it fall in time ‘t’?
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The newton-second is unit of:
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What is the speed of 2.9 kg metallic b ob at mean position of a simple pendulum, when release from its extreme position 0.5 m high? (g = 10m-2 )
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When the speed of your car is halved, by what factor does its kinetic energy decreases?
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Which one of the following force in non conservative force?
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The earth rotates on its axis once a day. Suppose, by dome process the earth contracts so that its radius is only half as large as at present, then how long the earth will take to complete its rotation?
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1 radian is equal to:
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In transmission from grid station, power losses are maximized by:
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The domestic electricity supply has a frequency of:
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PIV stands for:
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The wavelength associated with an electron is of the order of:
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Which photon carries the most energy?
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Which one of the following series lies in the ultraviolet region?
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The main difference between X-rays and γ rays is:
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There are initially 400 atoms in a radioactive sample. What of atoms after 3 half-life?
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Which using radiation theraphy, cancerous thyroid is treated with radioisotope:
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In capacitors, energy is stored in the form of:
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Ohm time’s farad is equivalent to:
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One kilowatt-hours is commonly termed as one commercial uniq of electric energy which is equal to:
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When a wire is compressed and its radius becomes 2R then its resistance will be:
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One of the following is an ohmicdevie:
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The change is resistance of metallic conductor at temperature below 0oC is:
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When current are flowing through two long parallel wires in same direction electric field between them is:
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Magnetic flux is maximum when angle between magnetic field and vector area is:
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Transformer is device which steps up or steps down the input:
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If a stationary bar magnet is places near a coil at rest so maximum lines of force passes through the coil, the galvanometer shows:
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Alkyl halides involving –C –X bond breakage and –C –Nu bond formation simultaneously would follow the mechanism
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Phenol is known as:
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Phenol is more acidic than alcohols because of the following reason:
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which of the following reagent is use to separate and purify carbonyl and non- carbonyl compounds?
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Hydrolysis of acyl chloride results in the formation of:
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The exact reactivity order for carboxylic acid derivatives is:
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Based on the physio – chemical properties, proteins may be classified into the following types:
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Based on function, thyroxin can be classified as:
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L-Asparaginase enzyme has been used for the treatment of:
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Potassium, Rubidium, Cesium react with oxygen to form which types of oxides?
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Magnesium reacts with nitrogen to form:
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Densities of alkali metals are low due to:
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In 3rd series of transition elements, paramagnetic behavior is maximum for Mn+2 and:
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Electronic configuration of chromium (proton number 24) is:
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The transition element which does not show variable valencyos:
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Select the organic compound which belongs to Arene family;
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The type of isomerism existing in a compound of molecular formula C2H60 is:
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Generic formula of cycloalkane is?
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Electrophile in sulphonation of benzene is:
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Acetophenoe can be formed by which of the following reaction of benzene?
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In alkanes, each carbon has hybridization:
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When CH3 is attached with the benzene ring, it makes the ring:
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Which of the following reaction has greater Kp than Kc (kp>Kc)
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The equation N2g + 3H2g = 2NH3, represents:
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The unit of the rate constant is the same as that of the rate of reaction in:
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The study of rates of chemical reactions and the factors that affect the rates of chemical reactions is known as:
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For the reaction A(g) -> products, when the concentration of A(g) doubles, the rate of reaction increases four fold, which means it is:
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For which of the following order of the reaction, rate of reaction in inversely proportional to the concentration reaction?
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The thermal energy at constant pressure is called:
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Born-Haber cycle is used to determine the lattice energies of:
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The oxidation state of ‘S’ in the (S2O3) -2 is:
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The common oxidation number of halogens is:
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During oxidation process, oxidation number of an element:
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Which of the following has the height value of electronegativity?
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Which of the following hybrid orbitals has maximum ‘S’ –character?>
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The first ionization energy is maximum for:
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The efficiency of chemical reaction cay be expressed as:
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In a vessel, 10g N2, 10g H and 10g O2 are present. Which one will have least number of atoms?
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The empirical formula of Glucose C6H12O6 is:
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The relationship between quantum number n and I is:
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Quantum number values for ‘2p’ orbitals are:
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Which pair has 1 electron in it’s ‘s’ orbital?
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According to the general gas equation density of an ideal gas depends upon:
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CO2 and SO2 both are tri-atomic molecules but heat of vaporization of SO2 is greater than that of CO2 due to:
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Which of the following has the lowest vapour pressure at 20oC?
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The lattice energy is also called as:
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For a gaseous phase reaction, when number of moles of reactants and products are equal:
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Purification of table salt (NaCl) by passing HCI gas through its saturated aqueous solution is an example of:
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We prefer fruits_____ sweets
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Choose the correct spelling
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Choose the correct spelling
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The Headmaster____ to speed to you
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Choose the correct option: Knowledge and wisdom____ no time for connection
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Identify the erros and choose the correct option: I hope this letters finds in the best of your spirits
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Fill in the blank with appropriate article as required. ___ Umbrella is of no avail against a thunderstorm
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Choose the correct sentence
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Pick the correct option
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Choose the correctly structured sentence.
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She always carried un umbrella. The sentence indicates___tense.
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Ahmed____ me for a long time
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Choose the correct option:
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Choose the correct option:
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Not only the parents but also their son ___ for interview
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When the temperature of the body surrounding rises, baby responds by
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The excretion of hypertonic urine in humans is associated best with the
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In humans, the temperature regulation control conter is located in
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As an excretory organ, liver
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The active uptake of sodium in the ascending limb or thick loop of henle is promoted by the action of
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Which of the following muscles are considered as ‘Voluntary Muscles’?
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Which one of the following ‘myoenic’ types of muscle?
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What do we call the cell surface membrane of a muscle fiber?
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Which of the following neurotransmitters function, both as neurotransmitter and hormones, decreasing our perception of pain?
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Which body function is controlled through positive feedback mechanism?
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Which of the following is common to all neurons?
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Neurons are cells adopted for the rapid transmission of electrical impulses. To do this, they have long thin process called:
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___ is a junction between two neurons or between a motor neuron and a muscle cell
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Which of the following represents the changes that occur in the ovary and the uterus approximately every 28 days involving evolution with the breakdown and loss of the linning of the uterus
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Which of the following disease is sexually transmitted?
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Which of the following hormones of the pituitary gland regulate the menstrual cycle?
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Which traits ar most likely to affect men than women?
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Alleles both have an effect on the phenotype heterozygotic organism
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When both the allele of a genes are same, the organism is said to be:
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In which type of cell. Cell wall is not present?
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70S size ribosomes are found in the cells of
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According to the fluid mosaic model of cell membrane, which zone is embedded inside?
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The membrane separating the vacuole from cytoplasm is called
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Select the one which is not a function of smooth endoplasmic retidulum (SER)?
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Which of the following organelles are involves in the synthesis of plant cell wall?
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Which property of water helps to maintain the integrity of cell membrances?
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Water act as universal solvent because of
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Lipids store double amount of energy as compared to carbohydrtes because of
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Which of the following is an unsaturated fatty acid?
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NAD is an example of
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Most enzymes have and optimum temperature of around
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Enzymes work by lowering the ___ of the reactions that catalyze
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First stable compound during calvin cycle is
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What is the function of ribulose?
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Which of the following process does not need pyruvic acid as a substrate?
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Which of the following is a copper containing protein in electron transport chain?
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In electron transport chain, ATP synthesis takes place when electron moves from
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“law of independent assortment” states
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Phenotype is
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In complete dominance
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Which one of the following is found both messgenger RNA an DNA of a mammalian cell?
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The cells in our body are all genetically identical apart from the
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Transcription is the process in which an RNA copy of the DNA sequence and coding the gene is produced with help of an enzyme called:
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Th particular array of chromosomes that an individual prossess is called its
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During meiosis, the homologous chromosomes comes together and form pairs this process is called
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At what phase the DNA content of a cell is doubled?
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Which statement correctly describes transcription of DNA?
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This theory says that “mitochondria and chloroplast area in effect ancient bacteria which now live inside the large cells”
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The organs which are similar but differ in structure are called
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____ occurs because natural selection gives some alleles a batter chance of survival than others
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The DNA that has been altered and which now contains length of nucleotides from two different organisms is called a
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It is a method for rapid production of a very large number of copies of a particular fragment of DNA
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What is the effect of DNA ligase?
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Which of the following is the components/ tools of recombinant DNA technology?
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Gel electrophoresis is a technique
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Transgenic organisms
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Which of the following is not necessary for PCR to occur?
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The end product of glycolysis in acrobic respiration is
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Which of the following is not related enveloped virus?
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Numerous opportunistic diseases might attack a persone suffering from which of the following disease?
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The complete, mature and infection virus particle is known as
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Which of the following is not TRUE about Human Immunodeficiency virus ( HIV)?
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Select a method which cause the oxidation of constituent of a bacterial cell
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Which of the following is TRUE about the structure if typical bacterium?
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Red algae do not contribute towards
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Which of the following is true about amoeba?
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The directional movement toward or away from the stimulus is called
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Photophosphorylation takes place in the ____ of the chloroplasts
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Select an anamniote from the following
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In roots the apoplast pathway of water is disrupted when water reaches
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Regarding structure of human heart chordae tendinea are present in
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The only vein in human body carrying oxygenated blood is
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The cells which play very important in developing immunity are
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Which of the following blood vessels have the highest pressure of blood?
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Autoimmune disease act at the principle of
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In human heart, the left atrium receives
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Antibodies are manufactured in
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