In an n-p-n transistor, 108 electrons are emitted from the emitter in 10-4 s. If 2% of electrons are lost in the base. Then the current gain in common-emitter configuration mode is
The output of combination of the gates as shown in figure is
Apply the truth table, verify with
The ratio of electron and hole currents in a semi-conductor is 7/5 and the ratio of drift velocities of electrons and holes is 7/4 , then the ratio of concentrations of electrons and holes will be
Suppose θ is polarising angle for a transparent medium and speed of light in that medium is v, then according to Brewster law.
An object is placed at a distance of 20 cm from a thin plano-convex lens of focal length 15 cm. The plane surface of lens is now silvered. What is the position of image?
An eye specialist prescribes spectacles having a combination of a convex lens of focal length 40 cm in contact with a concave lens of focal length 25 cm. The power of this lens combination is
A nucleus of mass number 220, initially at rest emits an α -particle. If the Q value of the reaction is 5 MeV, then the energy of emitted α -particle will be
A sample of radioactive material has a mass m, decay constant λ and molecular weight M. If avogadro’s constant is NA. Then initial activity of the sample is
Activity of radioactive element decreased to one –third of original activity io in 9 years. After further 9 years, its activity will be
Suppose the potential energy between electron and proton at a distance r is vary as U ∝ r2. Assuming Bohr's model of quantization of angular momentum and circular orbits, radius of the nth allowed orbit is proportional to
De-Broglie wavelength of an electron in the nth Bohr orbit is λn and the angular momentum is Jn then
Light with energy flux of 24 W/m2 is incident on a well polished disc of area 38.5 cm2 for one hour. The momentum transferred to the disc is
A body of mass 6 kg is lowered down with help of a string with downward acceleration g/4. The work done by the string on the body in first 3s after start of the motion is (g = 10 m/s2)
Light from three non-coherent sources, having same intensity, interfere at a location and produce resultant intensity 6I. If one of the three sources is switched off, then the resultant intensity at same point will be
In case of non-coherent sources I net = ∑/
Let intensity from one source by lo
3/o = 6/
⇒ lo =2/
If one source is switched off
Net intensity = 2/o = 4/
Figure shows a flywheel of radius 10 cm. Its moment of inertia about the axis of rotation is 0.4 kg m2. A massless string passes over the flywheel and a mass of 2 kg attached at its lower end. Angular acceleration of flywheel in (rad/s2) is nearly (g = m/s2)
Radius of a planet is three times the radius of the earth and it has same average density as that of the earth. The ratio of escape speeds from surface of the planet and that from the surface of earth is
Heat is supplied to a certain sample of a substance in solid state at a constant rate. The variation of temperature is plotted against time as shown in the figure. Choose the correct statement regarding the sample.
Since time required for same temperature increase is larger in liquid state than solid state, the specific heat capacity is higher in liquid state. Since in phase transition, the heat required is less in fusion than evaporation, hence latent heat of fusion is less.
A simple pendulum has a time period T in vacuum. Its time period when it is completely immersed in a nonviscous liquid of density one-fourth density of material of bob is
A car is moving on a road with a speed 40 m/s, blows a horn of frequency 200 Hz. The apparent wavelength of sound as observed by a detector on the road behind the car will be (Speed of sound in air is 340 m/s)
The resistance of a galvanometer coil is 48 Ω . The resistance of shunt required to convert it into an ammeter of range 6 times as that of galvanometer is
Six point charges are kept at the vertices of a regular hexagon of side length a and centre O as shown in the figure. Choose the correct statement.
Eo = Zero (as electric field of one charge cancelled by electric field of charge at diagonally opposite end)
A cylindrical vessel filled with water upto a height H becomes empty in time t, due to a small hole at the bottom of vessel. If water is filled in same vessel to a height 4H, then time in which water level will reduce to height H, is
If R1 and R2 are the radii of curvature of four double convex lenses made of same material, then lens with highest power is
Two points P and Q are maintained at the potentials of 10 V and -4 V respectively. The work done in moving 100 electrons from P to Q is
The ratio of the radii of he planets X and Y is α . The ratio of acceleration due to gravity is β . The ratio of the escape velocities from their surfaces will be
A uniform conductor of resistance R is cut into 20 equal parts. Half of them are joined in series and the remaining half of them in parallel. If the two combinations are joined in series, the effective resistance of all the pieces is
A satellite which is geostationary in a particular orbit is taken to another orbit. Its distance from the centre of earth in the new orbit is 2 times that of earlier orbit. The time period in the second orbit is
A 300 m long train is moving to north at a speed of 10 m/s. A bird flying towards south with a speed of 5 m/s crosses the train. The time taken by the bird to cross the train would be
A point moves along a circle with speed v = ατ the total acceleration of the point at a time when it has traced 1/8th of the circumference is
A capacitor of capacitance 1 μF is charged to 30 V and the battery is then disconnected. If it is connected across a 2 μF capacitor, the energy lost by the system is
A particle is moving along a circular path of radius 10 m with a uniform speed 10 m/s. What will be the average acceleration when the particle completes half revolution?
For half revolution
Change in velocity Δ V = 2 V and Time internal
∵ Average acceleration am
A block of mass m is suspended separately by two different springs and is having time periods T1 and T2 respectively. If same mass is connected to series combination of both springs, then its time period is
Series combination for springs
There are three vectors The unit vector along is
A small signal voltage V(t) = Vo sin ωt is applied across an ideal inductor L. Then
In purely inductive ac circuit, voltage leads current by phase 90o
A beam of light of wavelength λ = 500 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The width of central maxima is
Width of central maxima =
An electron in hydrogen atom makes a transition from n1 and n2. If the time period of electron in initial state is 27 times that in the final state then (Symbols have their usual meanings)
Two identical heavy spheres of masses 102 kg and each of radius 10 cm have a separation 100 cm between their centres. The gravitational potential at the midpoint of line joining their centres is
A parallel plate capacitor is charged by abattery and then isolated from it. If distance between the two plates is now increased, then
A black body is at temperature 700o C. It radiates thermal energy at the rate which is proportional to
On an imaginary scale of temperature X, the freezing and boiling points of water are 42o X and 192o X respectively. What will be the temperature on X scale corresponding to a temperature 42o C on Celsius scale is
An ideal heat engine operates in Carnot cycle between 227oC and 77oC. It absorbs 2 x 104 cal heat from source at high temperature. The amount of heat rejected to sink at lower temperature is
Consider a long steel bar under a tensile stress due to forces F acting at the edges along the length of the bar as shown in the figure. The cross-sectional area of the rod is A. The shearing stress on plane aa’ making angle θ with the length, is
A tuning fork of frequency 480 Hz is sounded on a resonance tube. The first and second resonance are observed at 16 cm and 50 cm respectively. The velocity of sound in air is approximately
Use concept of resonance with correction.
Displacement of a particle executing S.H.M is x = 7(sin πt + cos πt). The maximum speed of the particle is (where x is in m and t in s)
The self inductance L of a solenoid of length ℓ and area of cross-section A, for a fixed number of turns N will definitely decrease as
The ratio of velocity of electron in 2nd to that in 4th excited state of Be3+ will be
An example of tranquilizer is
Monomer of which of the following has atoms of only two different elements
Number of units of glucose contained by amylase is
Most basic out of the following is
No resonance and lone pair of electrons on sp3 hybridized N atom.
Consider the following reaction sequence
Select the incorrect statement in the following
∵ R – X, involves nucleophilic substitution reaction via SN2 mechanism hance – R must be 1o – alkyl group not a phenyl group.
Identify the products A and B of the following reaction
Select the compound which is most reactive towards SN2 reaction
Rate of SN2 reaction will be faster when transition state is more stable.
In which of the following, gauche form is more stable than anti form of conformers?
Gauche form can be more stable when intramolecular H-bonding occurs.
Which of the following will yield maximum terminal alkene?
Terminal alkene will be less substituted and called Hoffmann product.
Poor leaving group and sterically hindered base will favour formation of maximum Hoffmann product.
The compound showing maximum number of geometrical isomers is
More number of ligands
EAN rule is followed by
EAN = 26- 2 + 6 x 2 =36
Aqueous CuSO4 solution is blue in colour. Which colour is absorbed by it ?
Which of the following elements can form square planar fluoride?
XeF4 is square planner
Transition temperature of rhombic sulphur to monoclinic sulphur is
Which will have P-P bond?
Least amount of carbon is present in
During electrophoresis of purple of cassius, the colloidal particles will
Gold sol is negatively charged.
In a reaction, 64.2 M of reactant becomes 32.1 M in 20 second. After 30 second from the start of the reaction 16.05 M is left. The value of rate constant will be
It is zero order reaction,
Which of the following relation is correct for an electrochemical cell?
Correct comparison of ΔTb of the following (aqueous solution) is
1. 0.1 N NaCl
2. 0.1 N CaCl2
3. 0.1 N AlCl3
4. 0.1 N AI2 (SO)4
As no of ions increases, lowering of VP increases,
NaCl = 2 ion
CaCl2 = 3 ion
AlCl3 = 4 ions
and Al2(SO4)3 = 5 ions
so, correct order is I > II > III > IV
Number of tetrahedral voids present on edges of hcp unit cell is
The formation of photochemical smog does not involve
Magnetic moment of Fe2+ ion is
Magnetic moment =
(n = no, of unpaired electrons)
Magnetic moment =
Which of the following oxides is most acidic?
With the increase in oxidation number of central atom, acidic nature increases.
Van Arkel process for purification of impure Ti is represented by following scheme
Temperature T1 and T2 respectively are
Which thermodynamic property is not correct for adsorption of gases o solid surface?
During adsorption of gases on solid surface , entropy decreases.
If activation energy for forward direction is found to be greater than the backward direction for a reaction, then which of the following is always holds true?
The van’t Hoff factor (i) for a dilute aqueous solution of the strong electrolyte Na3AIF6 is
The vacant fraction in fcc unit cell is
Correct order of energy of 2s – orbital’s is
Higher is the Zeffective, closer the electron density from nucleus and lesser is the energy of 2s -orbital.
Be has lowest Zeffectice, for 2s electron hence highest is the energy of orbital.
Co-ordination number of Be in Beryllium chloride in solid state and at higher temperature of order of 1200 K respectively are
BeCI2 in solid state form polymeric chloro bridge compound,
At high temperature, it exist as linear monomer of form
Consider the following reactions1.
Compounds A, B, C and structure of C respectively are
When equal volumes of two solutions pH = 2 and pH = 3 are mixed together then the pH of resulting solution will be [log 5.5 = 0.74]
The reaction has begun with 10 mol of A in 10 L closed vessel. When equilibrium is reached, the concentration of C is 0.08 M. The value of equilibrium constant (KC) for this reaction is given by expression
Which of the following reactions, enthalpy, enthalpy correctly represents standard enthalpy of formation?
Enthalpy of formation is defined for 1 mol product formation, when reactants are present in their standard states. S8 (Rhombic) is standard state of sulphur and its combustion represents standard enthalpy of formation of SO2(g)
A certain gas takes five times as long to effuse out as H2(g) under identical conditions. Its molecular mass will be
Which of the following molecules contains equal number of σ and π- bonds ?
The correct shape of CI2 and hybridization of I in CI2 respectively are
An element has its electronic configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d8. In which group of periodic table this element can be placed?
Element belongs to d-block.
Element belongs to 4th period and 10th group.
Maximum number of electrons present in an atom having n = 3 and I = 2 is
n = 3 and I = 2, represents ‘3d’ orbitals.
Maximum number of electrons accommodated in 3d orbitals is 10.
Which of the following pairs of orbitals will have electron density along the axes?
Px , Py , Pz, and dx2-y2 orbitals are axial orbitals.
Number of nucleons present in 0.2 mol D2O is
Number of nucleons present in 1 molecule of D2O = 20.
Number of nucleous in 0.2 mol D2O
= 20 x 0.2 x NA = 4.0 NA
Which type of silicate is present in CaSi2O5?
is sheet silicate
Which of the following is/are aromatic?
The taxonomic unit ‘Phylum’ in the classification of animal is equivalent to which hierarchical level in classification of plants
Classes comprising animals like fishes, amphibians, reptiles, birds along with mammals constitute the next higher category called Phylum. All these classes are included in the phylum chordata. In case of plants, classes with a few similar characters are assigned to a higher category called Division.
All living organisms are linked to one another because
All living organisms share common genetic material, i.e., DNA but with variations, e.g., bacteria have single standed circular DNA while in highly evolved eukaryotic cells of plants and animals, DNA is a long double stranded helix.
Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to ?
Viruses did not find a place in classification since they are not truly ‘living’ if we understand living as those organisms that have a cell structure. Viruses are neither prokaryotes nor eukaryotes. They are inert outside their specific host cell and cannot multiply of their own because they lack cellular machinery to use its genetic material. Viruses can only multiply in host or living cell.
Members of Phycomycetes are found in
(i) Aquatic habitats
(ii) On decaying wood
(iii) Moist and damp places
(iv) As obligate parasites on plants
Choose from the following options.
Phycomycetes are the members of fungi that can thrive well on dead and decaying wood as saprophytes. These prefer to live in moist and damp places and need water for the movement of zoospore and sexual gametes and Few members of phycomycetes are obligate parasites like Phytophthora.
A dicotyledonous plant bears flowers but never Produces fruits and Seeds. The most probable cause for the above situation is
Fruits can develop from a single ovary of a single flower (simple fruit) or from several free carpels of a single flower (aggregate) or from whole inflorescence (multiple). In total, fruits develop from ovaries. This is why a dioecious plant (unisexual) bearing only staminate(male) flowers will not produce fruits, whereas monoecious plants (bisexual) or dioecious plant bearing only pistillate (female) flowers or pistillate and staminate both can bear fruits.
The outermost and innermost wall layers of microsporangium in an anther are respectively
A typical microsporangium is generally surrounded by four-wall layers, i.e., the epidermis, (outermost protective layer),endothecia, (middle fibrous layers) and the tapetum (innermost nutritive layer).
Starting from the innermost part, the correct sequence of parts in an ovule are
The correct sequence of parts in an ovule are
Autogamy can occur in a chasmogamous flower if
Autogamy is pollination within a flower. Chasmogamous flowers are those in which anthers and stigma are exposed. For autogamy, in such a flower to take place, pollen and ovule should mature simultaneously and anther and stigma should lie close to each other.
A particular species of plant produces light, non sticky pollen in large numbers and its stigma are long and feathery. These modifications facilitate pollination by
Pollination by wind is called anemophily. Anemophilous flowers are small, in conspicuous non-scented without bright colours, nectar and fragrance. Wind pollination also requires that the pollen grains are light and non-sticky which is in large numbers and its stigmas are long and feathery.
From among the situations given below, choose the one that Prevents autogamy and geitonogamy
Autogamy (same flower); geitonogamy (different flowers of same plants; xenogamy (different plant’s flower).
Dioecious plant bearing only male or female flowers prevents both autogamy and geitonogamy.
All genes located on the same chromosome
All the genes located on the same chromosome form one linkage group. A linkage group can be defined as all the genes on a single chromosome that move as a unit during the cell division. These genes do not tend to separate, until the crossing-over and if the distance between them is very less, they will not undergo the crossing-over. For examples, human beings have 23 linkage groups due to 23pairs of chromosomes.
Hence, the correct answer is 'Form one linkage group'
Production of no recombinants in offsprings indicates
Linkage is the phenomenon of physical association of genes on a chromosome and recombination is the generation of non-parental gene combinations. Strength of the linkage between two genes is inversely proportional to the, distance between the two, i.e., two linked genes show higher frequency of crossing over (recombination) if the distance between them is higher and lower frequency if the distance is small. But distance between gene has a direct relationship with percentage of recombination because with increase in distance between genes percentage of recombination increases.
So, the correct answer is 'A direct relationship'.
Person having genotype IA IB would show the blood group as AB. This is because of
Both genes are equally expressed hence its co-dominance
A cross between two tall Plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents?
Tt and Tt let's use Mendel's cross of tall and dwarf pea plants as an example. The F1 plants of genotype Tt are self-pollinated.(both tall (T) but with dwarf (t) alleles).
The letters T and t are used to represent the alleles of the gene that determine plant height by conventions. The upper case letter (T) represents the dominant allele and the recessive allele (t) is represented by the same letter in lower case. Thus, the tall parents plants having heterozygous alleles, results in off springs which comprises of both tall and dwarf plants. For the parental cross, both the parents are true breeding plants, the tall plant is homozygous for the tall allele T, while the dwarf plant is homozygous for the dwarf allele 't'. Mendel tracked each trait through two generations. When true breeding plants were crossed to each other, this is called a parental cross and offspring comprise the first filial or F1 -generation. When the members of the F1 - generation were crossed, this produced the F2-generation or second filial generation. A cross between true breeding tall and dwarf plants of the parent generation yield phenotypically tall plants. The cross between TT and Tt is called back cross, which results into two homozygous and two heterozygous dominant gametes. The cross between Tt and tt is called testcross which results into 1:1 ratio of gametes.
In a dihybrid cross, if you get 9:3:3:1 ratio it denotes that
Cross involving two contrasting characters is called dihybrid cross. The two flowers of each trait assort at random and independent of their traits at the time of meiosis (gametogenesis) and get randomly as well as independently rearranged in the offspring producing both parental and new combinations of traits. This explained the law of independent assortment given by Mendel.
Mendel’s law of independent assortment always holds good for genes situated on the
Mendal's Law of independent assortment tells us that the pairs of the alleles getsseparated when the gametes are being formed that means the traits or characters that are being transferred to the offspring are independent.
Now the non homologous chromosomes are different from each other completely and they not take part in crossing-over.
Occasionally, a single gene may express more than one effect. The phenomenon is called
Occasionally, a single gene may express more than one trait. This phenomenon is called pleiotropy. Sometimes, one trait will be very evident and others will be less evident, e.g., a gene for white eye in Drosophila also affect the shape of organs in male responsible for sperm storage as well as other structures.Similarly, sicklecell anaemic individuals suffer from a number of problems, all of which are pleiotropic effects of the sickle-cell alleles. Multiple allelism is a series of three or more alternative or allelic forms of a gene, only two of which can exist in any normal diploid individual, e.g., genes of blood groups in humans. Mosaicism describes the occurrence of cells that differ in their genetic component from other cells of the body. Polygeny refers to a single characteristic that is controlled by more than two genes.(it is also known as multifactorial inheritance).
In the F2 generation of a Mendelian dihybrid cross the number of Phenotypes and genotypes are
In the F2 generation of a Mendelian dihybrid cross the number of phenotypes and genotypes are 4, 9 respectively.
In a DNA Strand the nucleotides are linked together by
Two nucleotides are linked through 3 → 5 phosphodiester linkage to form a dinucleotide. More nucleotides are joined in a similar manner to form a polynucleotide chain.
Both deoxyribose and Ribose belong to a class of sugars called
Which of the following statements is the most appropriate for sickle cell anaemia?
Sick / cell anaemia: It is a molecular disease, autosomal recessive disorder and an example of pleiotropy. It cannot be treated with iron supplements and it confers resistance to acquiring malaria.
While analysis the DNA of an organism a total number of 5386 nucleotides were found out of which Guanine = 17% Cytosine = 32% Thymine = 17% Considering to Chargaff’s rule it can be concluded that
It cannot be a double stranded DNA because as per Chargaffs rule for a dsDNA, The ratios between adenine and thymine and guanine and cytosine are constant and equal. Hence it is a ssDNA.
BOD of waste water is estimated by measuring the amount of
BOD of waste water is estimated by measuring the amount of oxygen consumption.
The technology of biogas production from cow dung was developed in India largely due to the efforts of
The technology of biogas production from cow dung was developed in India largely due to the efforts of Indian Agricultural Research Institute (IARI) and Khadi & Village Industries Commission (KVIC) .
Mycorrhiza does not help the host plant in
Mycorrhiza help the host plant in enhancing its phosphorus uptake capacity, increasing its tolerance to drought and enhancing its resistance to root pathogens.
Salt concentration (salinity) of the sea measured in parts per thousand is
Salinity is the concentration of salt in water, usually measured in parts per thousand (ppt). The salinity of seawater in the open ocean is remarkably constant at about 35 ppt.
Formation of tropical forests needs mean annual temperature and mean annual precipitation as
The entire ecosystem is made up of biotic and abiotic factors. Temperature, rainfall, snowfall, constitute some important abiotic factors. As we move from the equator to poles, the temperature range goes on decreasing and rainfall varies from place to place. At the poles, there is hardly any rainfall but snowfall is seen very regularly. Fir tropical rainforests to grow, the temperature in the range of 18-25 degree Celcius is required. Rainfall of around 150-400 cm is also required for the same.
What will happen to a well growing herbaceous plant in the forest if it is transplanted outside the forest in a park ?
A well growing herbaceous plant in the forest if it is transplanted outside the forest in a park. It may not survive because of change in its micro climate.
If a population of 50 Paramoecium present in a pool increases to 150 after an hour, what would be the birth rate of population ?
Initial population of paramecium Pi = 50
After one hour population of paramecium Pf = 150
Number of one hour = Pf – Pi
= 150-50= 100
Birth rate = (No. of birth/existing population) * 100
What parameters are used for tiger census in our country's national park sand sanctuaries?
The parameters used for tiger census in our country's national park and sanctuaries are foot prints (pug marks) and faecal pallets of conserved animals.
During the process of ecological succession the changes that take place in communities are ?
During the process of ecological succession, the changes that take place in a community are in a defined hierarchy. They change in a common trend in which the no. of individuals and the biomass increases sequentially.
The sequence of communities of primary succession in water is
Primary succession in water is also called as hydrarch, which will lead from hydric to mesic conditions. Phytoplanktons(autotrophic) are generally the first to appear. Later zooplanktons feeding on phytoplanktons also appear. Next stage is characterized by the soft mud on the bottom having organic matter favouring the growth of rooted submerged plants. They are replaced by free-floating hydrophytes (Lemna, Wolffia etc). Rapid growth of these plants build up bottom as that water becomes shallow on periphery. In this shallow water, comes the reedswamp stage(e.g., Typha). They produce abundant organic matter. Next stages are sedge or marsh-meadow stage which transpire rapidly and build up soil, on which the next stage, trees can grow.
So, the correct answer is 'Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees'.
The historic convention on Biological Diversity held in Rio de Jenerio in 1992 is known as
The historic convention on biological diversity held in Rio de Janeiro (Brazil) in 1992 is known as Earth Summit (Ist). The explanation for other options is CITES (Convention on International Trade in Endangered Species of wild flora and fauna) has helped in restricting poaching and loss of rare species. MAB stands for Man and Biosphere Programme which undertakes establishment and maintenance of biosphere reserves.
Match Correctly the following and choose the correct option
The correct matches is
The binomial nomenclature was given by
Consider the following four statements whether they are correct or wrong
(i) The sporophyte in liverworts is more elaborate than that in mosses
(ii) Salvia is heterosporous
(iii) The life-cycle in all seed bearing plants is diplontic
(iv) In pinus male and female cones are borne on different trees
The two wrong statements together are
The scutellum observed in a grain of wheat or Maize is comparable to which part of the seed in other monocotyledons ?
The scutellum is part of the structure of a barley and rice seed, the modified seed leaf. The scutellum can also refer to the equivalence of a thin cotyledon in monocots. It is very thin with high surface area and serves to absorb nutrients from the endosperm during germination. The scutellum is believed to contain an as yet unidentified protein transporter that facilitates starch movement from the endosperm to the embryo.
The technical term used for the androecium in a flower of (Hibiscus rosasinensis) is
Which one of the following is not a lateral meristem ?
Intercalary meristem- Grasses have intercalary meristems located along the stems near the nodes. Cell divisions in this tissue push the stem upward. Grasses and other monocots have no lateral meristems so any lateral increase in size, is the result of primary tissue cell enlargement, not cell divisions. It is a primary meristem. Intrafascicular cambium, interfascicular cambium and phellogen are lateral meristems involves in secondary growth.
Heartwood differs from sap wood in
The older woody trees show two characteristic types of wood namely heartwood and sapwood. The heartwood is made up of dead xylem vessels that have been filled with tyloses and are rich in deposits of resins and tannins. These are nonfunctional and appear darker. The sapwood contains the newly formed vessels that are functional and appear lighter. The hardwood provides resistance from the pest attack and increases the durability of the wood.
Hence, the correct answer is 'Having dead and non-conducting elements'
C4 plants are more efficient in photosynthesis than C3 plants due to
In C3 plants, CO2 is pumped directly into the Calvin cycle, leaving rubisco exposed to O2. Rubisco in a C3 will take up O2 rather than CO2 to undergo photorespiration. Photorespiration occurs under low concentrations of CO2 and high concentrations of O2. This process reduces efficiency of photosynthesis, potentially reducing photosynthetic output by 25% in C3 plants. C4 plants capture carbon dioxide in their mesophyll cells forming oxaloacetate. This oxaloacetate is then converted to malate and is transported into the bundle sheath cells, where oxygen concentration is low to avoid photorespiration. So, C4 plants are more efficient in photosynthesis than C3 plants.
The energy-releasing metabolic process in which substrate is oxidized without an external electron acceptor is called
Fermentation is incomplete oxidation of food substances in absence of oxygen (external electron acceptor) into alcohol or lactic acid with the small amount of energy being released. Aerobic respiration uses oxygen as an electron acceptor for oxidation of substrates. Glycolysis is the first common stage of both fermentation and aerobic respiration. Photorespiration is oxidation of RuBP by enzyme RUBISCO and does not produce energy.
Apomictic embryos in citrus arise from
Apomixis is a kind of asexual reproduction in which viable embryo is formed within the confines of the seed coat, without meiosis and syngamy. Adventive embryony is a type of Apomixis found in Citrus in which there is the formation of extra embryos due to sporophytic budding. One or more diploid sporophytic cells, either nucellus or integuments undergo stages of embryogeny and eventually develop into mature embryos.
Hence, in Citrus apomictic embryos arise from maternal sporophytic tissue in the ovule.
Phototropic curvature is the result of uneven distribution of
F. W. Went found that when the tip of Avena coleoptile is cut, its elongation ceases. However, when auxin was added externally, its growth renewed. He suggested that experiments suggested that auxin is synthesized in the coleoptile tip and is translocated downwards towards the gravity. It moves from illuminated side to shaded side. More auxin is present on the shaded side than on the illuminated side. Due to this, the plant to grow more on the shaded side and bend in the direction of the light source. It shows positive phototropism where faster cell elongation is seen on the shaded side and less on the illuminated side.
Transfer of pollen grains from the anther to the stigma of another flower of the same plant is called
Reptiles are most successful land animal in vertebrate. Which type of locomotion is found in them?
Which of the following group of the animals belongs to pseudocoelomates ?
Two kingdom classification was established by:
What is the main function of prostomium in earthworm?
Earthworms use the prostomium to see their environment, as earthworms have no eyes, ears, nose or hands. They depend on the prostomium and skin to help it feel their way through the soil.
What is the principal role of white blood cells in humans?
WBC helps in immunity
Nucleus is the site of
In nucleus there is a region called nucleolus there will be the synthesis of r-RNA
Classification of chromosomes with regards to shape based on:
Classification of chromosomes is based on position of middle part of centre of chromosome which is known as centromere.
Chromosome with centromere slightly away from centre is known as
Sub-metacentric chromosome or submedian centromere: The centromere is present slightly away from the centre of a chromosome or nearer to one end of the chromosome. As a result, chromosome is divided into one shorter and one longer arm.
Macro molecule chitin is
Chitin is a long-chain polymer of a N-acetylglucosamine. It is a nitrogen containing polysaccharide and a derivative of glucose. It is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans and insects, the radulae of molluscs, and the beaks and internal shells of cephalopods, including squid and octopuses.
The essential chemical components of many coenzymes are
Essential chemical components of many coenzymes are vitamins, e.g, coenzyme nicotinamide adenine dinucleotide (NAD) and NADP contain the vitamin niacin.
Where do certain symbiotic microorganisms normally occur in human body?
Caecum, a part of large intestine, is a small blind sac which hosts some symbiotic micro-organisms which helps in synthesis of Vitamin- B12 and helps in digestion
Argentaffin cells in human beings are found in
Argentaffin refers to cells which take up silver stain. Enteroendocrine cells are sometimes also called "argentaffins", because they take up this stain. An argentaffin cell is any enteroendocrine cell, a hormone-secreting cell present throughout the digestive tract.
Which of the following is is true about Inspiratory capacity
The most powerful respiratory stimulus for breathing in a healthy person is
Normally, an increased concentration of carbon dioxide is the strongest stimulus to breathe more deeply and more frequently. Conversely, when the carbon dioxide concentration in the blood is low, the brain decreases the frequency and depth of breaths.
When we breathe in, we inhale many gases, including oxygen, What happens to the gases that the body can’t use?
When we inhale, many gases are present in air, as the saying goes, the air we inhale includes oxygen carbon dioxide etc,when we exhale,the gases that is not needed will be released.
The cells involved in inflammatory reactions are
The heart sound (lubb) is associated with the closure of–
The correct option is Option D.
The first heart sound (lubb) is associated with the closure of tricuspid and bicuspid valves, where as the second heart sound (dupp) is associated with the closure of the semilunar valves.
What would be the cardiac output of a person having 72 heart beats per minute and a stroke volume of 50 ml?
The cardiac output of a person is calculated by multiplying the stroke volume and the heart rate. Hence, to alter a person’s cardiac output both the stroke volume and the heart rate can be altered. So, the cardiac output of a person having 72 heart beats per minute and a stroke volume of 50 mL would be 72 x 50 = 3600 mL.
Least toxic nitrogenous waste is
Nitrogenous waste that is produced in the body needs to be excreted from the body as they are toxic to an organism. The waste is excreted in 3 forms, namely ammonia, uric acid, and urea. Ammonia is more water-soluble and most toxic. It requires less energy for excretion. Animals excreting nitrogenous waste in the form of ammonia are called as ammonotelic. Aquatic animals like protozoans, crustaceans, poriferans, fishes where water is not a constraint are ammonotelic. Urea requires comparatively more energy and is less toxic in nature. Animals excreting nitrogenous waste in the form of urea are called as ureotelic. Examples include cartilaginous fish, amphibians, mammals including humans. Uric acid is least soluble in water and is least toxic. However, it requires a large amount of energy. Examples include reptiles, birds.
Vasa recta is
PCT helps to maintain the pH and ionic balance of body fluids by
PCT also helps to maintain the pH and ionic balance of the body fluids by selective secretion of hydrogen ions, ammonia and potassium ions into the filtrate and by absorption of HCO-3 from it.
Bone has a very hard matrix due to presence of
The hardness and rigidity of bone is due to the presence of mineral salt in the osteoid matrix, which is a crystalline complex of calcium and phosphate (hydroxyapatite).
Gout is the inflammation of joints due to accumulation of
Gout occurs when urate crystals accumulate in your joint, causing the inflammation and intense pain of a gout attack. Urate crystals can form when you have high levels of uric acid in your blood. Your body produces uric acid when it breaks down purines — substances that are found naturally in your body.
Knee joint and elbow joints are examples of
There are many joints present in the skeleton. Joint is a point of contact between two bones. The various type of joints present in the body are:
Ball and socket joint : Ball of one bone articulates in the socket of another bone. Head of the humerus and glenoid cavity of the pectoral girdle, femur and acetabulum, the joint between incus and stapes.
Hinge joint : Movement is possible in one direction only. Joint of malleus and incus, knee joint, elbow joint, articulation joint of the lower jaw.
Pivot joint : Helps in turning moments. One bone is fixed and second articulate. Atlas and axial of skull rotate with Axis vertebra
Gliding joint : Limited movement in all directions. Radius and ulna
Saddle joint : It is a ball and socket like a joint but not developed fully. Metacarpals of thumb and carpels of hand.
Which of the following cells form myelin sheath around axon?
Myelin is formed by Schwann cells in the peripheral nervous system (PNS) and oligodendrocytes in the central nervous system (CNS). Each Schwann cell forms a single myelin sheath around an axon.
Which of the following increases when an action potential is initiated?
The correct sequence meninges from inner to outerside is–
The meninges is the membranous coverings of the brain and spinal cord. It has three layers of protective tissues namely, dura mater, arachnoid mater and pia mater. Dura mater is the outermost covering present underneath the bones. Arachnoid is the middle layer present underneath the dura mater. There is space called sub-arachnoid space directly underneath the arachnoid. It contains cerebrospinal fluid, which acts as cushion for the brain. Pia mater is present underneath the sub-arachnoid space. It is adhere to the surface of brain and spinal cord.
Which of the following hormones(s) is/are called emergency hormone(s) of “fight or flight”?
Which of the following hormones does not act by a second messenger system?
Beause it's a steroid hormone and act on intracellular receptor.
Injury localized to the hypothalamus would most likely disrupt :
The primary function of the hypothalamus is homeostasis, which is to maintain the body's normal temperature and body's status. So, if there is an injury to the hypothalamus, the thermoregulatory centre is disturbed resulting in deregulation of body temperature.
In human oocyte meiosis II completes?