InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 951. |
The density of copper is 8.95 g `cm^(-3)` .It has a face centred cubic structure .What is the radius of copper atom? Atomic mass Cu =63.5 `gmol^(-1)N_(A)=6.02xx10^(23) mol^(-1)` |
|
Answer» `d=(Zm)/(a^(3)xxNa)` `rarr 8.95=(4xx63.5)/(a^(3)xx6.02xx10^(23)` `a^(3)=(4xx63.5)/(8.95xx6.02xx10^(23)=4.71xx10^(-23)=.0047xx10^(-2)a=0.167xx10^(-7)` `r=(a)/(2sqrt(2))=(0.167xx10^(-7))/(2xx1.414)`=127.8 PM |
|
| 952. |
Some ethylene glycol `HOCH_(2)CH_(2)OH` is added to your car cooling system along with 5 kg of water .If the freezing point of water glycol solution is `-15.0^(@)C` what is the boiling point of the solution ? `(k_(b)=0.52 kg mol^(-1)` and `k_(f)=1.86 k kg mol^(-1)` for water) |
|
Answer» `triangleTf=KfxxxM` `0-(-15)=1.86xxM` `M=(15)/(1.86)=8.06=4.1912` `triangleTb=4.1912 Ts-T^(@)A=4.1912+100` `Ts=104.19^(@)C` |
|
| 953. |
Hydrogen peroxide `H_(2)O_(2)` (aq) decomposes to `H_(2)O`(l) and `O_(2)`(g) in a reaction that is first order in `H_(2)O_(2)` and has a rate constant `k=1.06xx10^(3) min^(-1)` (i) How long will it takes for 15% of a sample of `H_(2)O_(2)` to decompose? (ii) How long will it take for 87.5% of the sample to decompose? |
|
Answer» (i) `t=(2.303)/(k)log[(A)]/[(A)]` Given `k=1.06xx10^(-3) min^(-1) [A]/[A]=100/85` `t=(2.303)/(1.06xx10^(-3)min^(-1)log100/85` `t=(2303)/(1.06)[2 log 10 -log85]min` `t=(2303)/(1.06)[2xx1-1.9294]=(2303xx0.0706)/(1.06)` t=153.39 min =153.4 min (ii) Given `k= 1.06xx10^(-3)min^(-1) [A]/[A]=100/15` `t=(2.303)/(1.06)(10^(-3)min^(-1)log(100))/(15)` `=(2303)/(1.06)[2log 10-log15]min =(2303)/(1.06)[2xx1-1.1761]` `=(2303xx0.8231)/(1.06)`min t=1790 min |
|
| 954. |
(A) complete the following chemical equations : (i) `Cu+HNO_(3)` (dilute) `to`(ii) `XeF_(4)+O_(2)F_(2)to`(B) Explain the following observations: (i) Phosphorus has greater tendency for catentation than nitrogen. (ii) Oxygen is a gas but sulphur a solid. (iii) The halogens are coloured. Why ? |
|
Answer» (a) (i) `3Cu + 8HNO_(3)` (dilute) `to Cu(NO_(3))_(2) + 2NO + 4H_(2)O` (ii) `XeF_(4) + O_(2)F_(2) overset(143K)(to) XeF_(6)O_(2).` (b) (i) Phosphorus has greater tendency for catenation than nitrogen . Due to greater bond strength of P-P single than N-N single bond . (ii) Oxygen is a gas but sulphur a solid. Sulphur because of its bigger size and lower electronegatively , prefers to form S-S single bonds . Further because of stronger S-S than O-O single bonds , sulphur has a much greater tendency for catenation than oxygen . (iii) Halogen are coloured . It is due to reason that their molecules absorb light in the visible region as a result of which their electrons get excited to higher energy levels while the remaining light is transmitted. |
|
| 955. |
Complete the following chemical reaction equations : (i) `underset(("cold and dilute"))(NaOH) + Cl_(2) to ` (ii)` underset(("excess"))(XeF_(6)) + H_(2)O to ` |
|
Answer» (i) `underset(("cold and dilute"))(2NaOH + Cl_(2)) to NaCl + NaOCl + H_(2)` ` (ii) underset(("excess"))(XeF_(6)+ 3 H_(2)O) to Xe O_(3) + 6 HF` |
|
| 956. |
Define the folowing : (i) Peptization (ii) Reversible sols |
|
Answer» (i) Peptization : It is the process of converting a precipitate into colloidal sol by shaking it with dispersion medium in the presence of a small amount of electrolyte. (ii) Reversible sols : The sols that can be made again by simply remixing with the dispersion medium and shaking are called reversible sols. |
|
| 957. |
Define the following terms? (i) Adsorption (ii) Peptization (iii)Sol |
|
Answer» )(i) see Q 19 set II(O.D)-2013 (ii) See Q 19 (ii) Set III (O.D)-2013 (iii) Sol: when dispersed phase is solid and despersion medium isliquid |
|
| 958. |
Explain the following terms : `(i) "Peptization"" "(ii)"Loyphobic colloids"" "(iii)"Dialysis"` |
|
Answer» (i) Peptization : It is a process of conveting a precipitate into colloidal particles by shaking it with dispersion medium in the presence of a small amount of a suitab le electrolyte. Lyophobic colloids: Substances like methals and their suphides etc., when simply mixed with dispersion medium do not form the colloidal sol. They are prapared by only special methods. Such substances are called loyphobic and the sol. Formed by them are called lyophobic colloids. (iii) Dialysis : The process of sparating the particcles of colloids from those of crystalloids by diffusion of mixture through a membren is known as dialysis. |
|
| 959. |
Define the following terms with an example in each case: (i) Macromolecular sol (ii) Peptization (iii) Emulsion |
|
Answer» (i) Macromolecular sol : When substances which possess very high molecular masses are dispersed in suitable dispersion medium, the colloidal solution formed are called macromolecular colloids. (ii) Peptization : Process of conversion of a fresh precipitate into sol by shaking it with disperion medium-in the presence of electrolyte is called peptisation. |
|
| 960. |
Write the shucture of prop-2-en-1-amine. |
| Answer» `H-overset(H)overset(|)underset(H)underset(|)C-overset(H)overset(|)C=underset(H)underset(|)C-NH_(2)` | |
| 961. |
Name the principal ore of aluminium. Explain the significance of leaching in the extraction of aluminium. |
| Answer» Bauxite is the main ore of aluminium. If is con centrated by leaching. This method removes the impurities of `SiO_(2), Fe_(2)O_(3),TiO_(2)` etc from the bauxite ore by various chemical reactions stepwise either in the precipitate form or in soluble form. | |
| 962. |
(a) What type of semiconductor is obtained when silicon is doped with boron ? (b) What type of magnetism is shown in the following alignment of magnetic moments? `uarr uarr uarr uarr uarr uarr` (c ) What type of point defect is produced when AgCl is doped with `CdCl_2` ? |
|
Answer» (a) When silicon is doped with boron, P-type semiconductor is obtained. ltbr. (b) The magenetism shown in the alignment of magnetic moments is ferromagnetism. (c ) impurity defect is produced when AgClis doped with `CdCl_2`. |
|
| 963. |
(a) What change occurs when AgCl is doped with `CdCl_(2)` ? (b) What type of semiconductor is produced when silicon is doped with boron? |
|
Answer» (a) `CdCl_(2)` on adding to AgCl introduces impurity defect. The addition of one `Cd^(2+)` ion will replace two `Ag^(+)` ions to maintain electrical conductivity. One of the position of `Ag^(+)` will be occupied by `Ca^(2+)` ion and other will be left as a hole. Thus, a hole is created similar schottky defect. (b) P-type semiconductor is produced when silicon is doped with boron, because silicon is belongs to group 14. |
|
| 964. |
Mention the importance of Lactic acid bacteria to humans other than setting milk into curd. |
| Answer» Lactic acid bacteria play a very beneficial role in checking disease causing microbes. | |
| 965. |
Name the group of bacteria involved in setting milk into curd. Explain the process they carry in doing so. Write another beneficial role of such bacteria. |
|
Answer» Lactobacillus of lactic acid bacteria (LAB) are involved in setting milk into curd. A small amount of curd that contain Lactobacillus are added in milk, bacteria grows produces lactic acid that cause coagulation of protein in milk to form curd. LAB also increases vitamin `B_(12)` along with other vitamins in the curd. |
|
| 966. |
Name any two common Indian millet crops. State one characteristic of millets that has been improved as a result of hybrid breeding so as to produce high yielding millet crops. |
|
Answer» Two common Indian millet crops : Maize and Jowar : Hybrid breeding has resulted in the production of high yielding millet varieties that are resistantto water stress. |
|
| 967. |
(b) Mention what would happen if lactose is withdrawn from the culture medium. |
| Answer» If lactose is withdrawn from the culture medium the repressor of the operon is synthesized from the i-gene. The repressor protein binds to the operator region of operon and prevents RNA polymerase from transcribing the operon. | |
| 968. |
Explain the mechanism of Sex-determination in birds. |
| Answer» Sex chromosomes in birds are determined as Z and W. The male is homomorphic (ZZ) and the female is heteromorphic (ZW). The W chromosome carries females sex-determining ,genes, and the duplication of Z chromosomes indicates the male sex. | |
| 969. |
Write the chromosomal basis of sex determination in birds. |
| Answer» In birds, female has a pair of dissimilar chromosomez ZW and male has two similar 22 chromosomes. | |
| 970. |
a) How do DNA fragments migrate and resolve in a Gel electrophoresis? b) How lane one is different from lane 2,3 and 4 in the GEL electrophoresis set up? c) How pure DNA fragments are made observable in the visible light? |
|
Answer» (a) The DNA fragment resolve according to their size through sieving effect provided by the agarose gel. Hence, the smaller the fragment size, the farther it moves. (b) The given agarose gel electrophoresis shows migration of undigested DNA fragments in lane 1 and digested set of DNA fragment in lane 2 to 4. (c) The separated DNA fragment can be visualized only after staining the DNA with a compound known as ethidium bromide followed by exposure to UV radiation. |
|
| 971. |
Cucurbits and papaya plants bear staminate and pistillate flowers. Mention the categories they are put under separately on the basis of the type of flowers they bear. |
| Answer» Cucurbits are monoecious and papaya is dioecious. | |
| 972. |
(a) Write the desirsble characters a farmer looks for in his sugarcane crop. (b) How did plant breeding techniques help north Indian farmers to develop cane with desired characters ? |
|
Answer» Saccharum barberi was originally grown in north Inadian , but had poor sugar content any yield . Tropical canes grown in south India saccharum offcinarum had thicker stems and higher suger content but did not grown well in north India . These two species were successfully crossed to get sugarcane varieties combining the desirable qualities of high yield , thick stems, high sugar and ability to grow in the sugarcane areas of north India. (b) Plant breeding is the purposeful mainipulation of plant species in order to create desired plant types that are better suited for cultivation give better yields and are disease rresistant. Conbentional plant breeding has been practiced for thousands of years since the beginning of human civilisation , recorded evidence of plant breeding dates back to 9,000-11 ,000 years ago. |
|
| 973. |
Explain the advantage of cross breeding of the two species of sugarcane in India. |
| Answer» Saccharum barberi, grown in North India, had poor sugar content and yield, where as Saccharum officiharum. Fm in south India, had thicker Item and higher sugar content. The sauger content species obtained that cross breeding, the two species had thick stema, high sugar, high yield And ability to grow in North India. | |
| 974. |
Differentiate between geitonogamy and xenoghmy in plants. Which one between the two will lead to inbreeding depression and why |
|
Answer» Geitonogamy : Transfer of pollen grains from the anther to the stigma of another flower of the same plant. Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the oeme plant. Xenogamy : Transfer of pollen grains from anther to the stigma of a different plant. This is the only type of pollination during which pollination brings genetically different types of pollen grains to the stigma. Geitonogamy leads to inbreeding depression because here the pollen grains come from the same plant |
|
| 975. |
Write the functions of the following in biotechnology : (a) polymerase chain reaction technique (b) Restriction endonucleases. (c ) Bacterium thrmus aquaticus. |
|
Answer» (i) Polymerase chain reaction technipue is used to prepare multiplecopies gene of interest in vitro using two sets of primers and the enzyme DNA polymerase. (ii) Restriction endonucleases make cut at specific positions within DNA. (iii) It produces an enzyme Taq polymerase which is resistant to denaturation by heat. The enzyme is used to amplify a specific DNA fragment in PCR technique. |
|
| 976. |
When and where are primary oocytes formed in a human female ? Trace the development of these occytes till ovulation (in menstrual cycle). How do gonadotropins influence this developmental process ? |
|
Answer» Oogenesis : (i) The process of formation of a mature female gamete or ova in the ovary is known as oogenesis. (ii) Germ cells of female foetus divide to produce oogonia which later grow into ovarian follicles. (iii) Oogonia start dividing and enter into prophase -I of the miotic division and get temporarily arrested at that stage, called primary oocytes are enclosed by a layer of granulosa cells, the follicle cells, and known as primary follicle. (iv ) The primary follicles get surrounded by more layers of granulosa cells and a thecal layer known as secondary follicles. (v) The secondary follicle soon transforms into a tertiary follicle which is characterised by a fluid-filled cavity called antrum. (vi) Primary oocyte undergoes first meotic division and produce two haploid cells: a large haploid secondary oocyte and a small first polar body. Secondary oocyte moves into the fallopian tube. (vii) When a sperm enters its cytoplasm, secondary oocyte completes meosis-II. ( viii) The secondary oocyte undergoes the second meotic division and produces a mature ovum and a second polar body. (ix) Polar bodies have no function and eventually degenerate. (x) Mature follicle of Graafian follicle ruptures to release the ovum from the ovary by the process called ovulation. Effect of gonadotropins : The primary follicle in the ovary grows and becomes a fully mature Graffian follicle. The endometrium of the uterus is regenerated due to the secretion of LH and FSH from anterior pituitary and ovarian hormone, estrogen. It lasts for about 14 days. Rapid selection of LH (LH surge) induces rupture of Graafian follicle and thereby leading to ovulation (release of ovum). |
|
| 977. |
(a) When and where does spermatogenesis occur in human male ? (b) Draw a diagram of a mature human male gamete ,Label the following parts : acrosome, middle piece and tail mention the function of acrosome and middle piece |
|
Answer» (a) In tests , the immature male germ (spermatogonia) produce sperms by spermatogenesis that begin at puberty. (b) See Q.29,(or) Set-III , Delhi Board-2009 Functtion of acrosome: A plasma members envelops the whole body of sperm . The sperm head contains an elongated haploid nucels , the anterior portion of which is covered by a cap-like structure called acrosome . The acrosome is filled with enymes that help fertilise te ovum . Funcultion of middle piece : Middle piece dcontains a number of mitochondria , that provide energy for the motility of sperms. |
|
| 978. |
Describe the responsibility of GEAC set up by the Indian Government. |
| Answer» GEAC (Genetic Engrneermg Approval Committee) make decisions regarding the valadity of GM research. It also checks the safety of introducing GM-organisms for public services for their large scale use | |
| 979. |
How has mutation breeding helped in improving the production of mung bean crop? |
| Answer» Mutation can be induced artificially through chemicals as well as through gamma radiations. The plants with desirable mutations can be selected and chosen as a source for breeding. This is called mutation breeding. This procedure has helped mung bean production by providing resistance against yellow mosaic virus and powdery mildew (fungal disease). | |
| 980. |
Differentiate between male and female heterogamety. |
| Answer» Heterogamety means different sex-gametes. Male heterogamety includes human males having XY sex chromosomes and males of some insects, such as grasshopper and bugs, having XO sex chromosomes. Female heterogamety includes females of some species of birds, fishes, and insects. females of butterfly and moth consist of ZO sex chromosomes, while fe1nales of fish, reptiles, and birds consist of ZW sex chromosomes. | |
| 981. |
Indiscrimate diagnostic practices using X- rays etc, should be avoided . Give one reason. |
| Answer» X-rays are ionizing radiation .They cause adverse effects in childern in the form of genetic changes , that is they alter the gencetic make- up of an organisms. | |
| 982. |
Biopiracy should be prevented. State why and how |
| Answer» Biopiracy is unauthorised exploitation of developing or under developed countries. Hence, it should be prevented. It can be prevented by developing laws to obtain proper authorisation and by paying compensatory benefits. | |
| 983. |
Why is tobacco smoking associated with rise in blood pressure and emphysema (oxygen deficiency in the body) ? Explain. |
| Answer» Tobacco has nicotine that stimulates the release of adrenaline and noradrenaline which raise blood. pressure. Smoking tobacco releases carbon monoxide which reduces the concentration of haem-bound oxygen. This causes emphysema. | |
| 984. |
Explain with the help of a suitable example the inheritance of a trait where two different dominant alleles of a trait express themselves simultaneously in the progeny. Name this kind of inheritance pattern. |
|
Answer» This can be explaind by studying the inheritance of ABO blood group in a progeny born to parents heterozygous for blood group A and blood group B. e.g : Father Heterozygous for blood group. A. `darr` `"Genotype " : I^(A)i` `darr` Mother Heterozygous for blood group B. `"Geneotype " : I^(B)i` On Crossing `{:(, I^(A), i), (I^(B), I^(A)I^(B), I^(B)i), (i, I^(A)i, ii):}` In this cross, progeny with blood group AB is produced resulting from the simantaneous expession of dominant alleles `I(A) " and " I^(B)`. This pattern of inheritance is called Co-dominance. |
|
| 985. |
What are Cry genes ? In which organism are they present? |
| Answer» The toxin coded by gene named Cry . The troteins encoded by the genes Cry I Ac and Cry II Ab gt Bt toxin genes were isolated from Bacillus thuringiensis. | |
| 986. |
What type of organs eye of an Octopus and that of a human called? Give another example from the animal group and one from the plants of such organs. Name and explain the evolutionery process they exhibit. |
|
Answer» Analogous organ is found in both octopus and human . For example : wings of butterfly and of birds look alike. They are not anatomically similar structures though they perform similar functions. Similarly in plants : Sweet potato and potato is another example of analogy. They exhibit convergent evolution : different structures evolving for the same function and hence, having similarity. |
|
| 987. |
(a) Explain the steps involved in in-vitro fertilisation popularly known as test tube baby programme. (b) State the importance of this programme. |
|
Answer» (a) IVF followed by embryo transfer is one of such methods. In this method popularly known s test tube baby programme, ova from the wife/ donor (female) and sperms from the husband / donor (male) are collected and are induced to from zygote under stimulated conditions in the lab. The zygote or early embryos could then be transferred into the fallopian tube. (b) The importance of this programme: * Inability to coneive or produce children even after 2 years of unprotected sexual cohabitation, then IVF is the best method for such couples. * For women with blocked or damaged fallopian tubes, IVF provides the best opportunity of having a child using their own eggs. |
|
| 988. |
Mention the polarity of DNA stands a - b and c -d shown in the replicating fork given below. |
|
Answer» a -b has polarity `3^(1)-5^(1)` continuous synthesis. c - d has polarity `5^(1)-3^(1)` Discontinuous synthesis. |
|
| 989. |
Mention the polarity of DNA stands a - b and c -d shown in the replicating fork given below. |
|
Answer» a -b has polarity `3^(1)-5^(1)` continuous synthesis. c - d has polarity `5^(1)-3^(1)` Discontinuous synthesis. |
|
| 990. |
Name the type of immunity the coloctrum provides to a newborn baby . Write giving an example where this type of immunity should be provided to a person. |
| Answer» Passive immunity . In case of infection by deadly microbes or snake bite , where quick immune response is required. | |
| 991. |
Name the type of immunity the colostrum provides to a newborn baby . Write giving an example where this type of immunity should be provided to a person. |
| Answer» Passive immunity . In case of infection by deadly microbes or snake bite , where quick immune response is required. | |
| 992. |
Write the binomials of two fungi and mention the profucts/bioactive molecules they help to produces. |
| Answer» Cyclosoprin A, that is used as an immunosuppressive agnet in organ transplant patients , is produced by the fungus trichoderma polysporumstatins produced bby the yeasr. Monascus purpureus have been commercialised as blood- cholesterol lowering agents. | |
| 993. |
The half -reactions of an electronchemical cell are given below : `MnO_4^(-)+8H^+(aq) +5e^(-)toMn^(2+)(aq)+4H_2O(l),E^o=+1.51V` `Sn^(2+)(aq)toSn^(4+)(aq)+2e^(-),E^o=+0.15V` Construct the redox equation from the standard from the standard potential of the cell and predict it the reaction is reactant favoured or product favoured. |
| Answer» See Q. 11, (or part), Set-I, O.D ., 2010. | |
| 994. |
Two half cell reactions of an electrochemical cell are given below : `MnO_(4)^(-)(aq)+8H^(+)(aq)+5e^(-),toMn^(2+)(aq)+4H_(2)O(l),E^(@)=+1.51V` `Sn^(2+)(aq)toSn^(4+)(aq)+2e^(-),E^(@)=+0.51V` Construct the redox equation from the two half cell reactions and predict if the reaction favours formation of reactant or product shown in the equation. |
|
Answer» At anode (oxidation) : `Sn^(2+)(aq)toSn^(4+)(aq)+2e^(-),E^(@)=+0.15V` At Cathod (reduction0 : `MnO_(4)^(-)(aq)+8H^(+)(aq)+5e^(-)toMn^(2+)(aq)+4H_(2)O(l),E^(@)=+1.51V` Thus over all redox equation is `5Sn^(2+)(aq)+2MnO_(4)^(-)(aq)+16H^(+)(aq)to5Sn^(4+)(aq)+2Mn^(2+)(aq)+8H_(2)O(l)` `E_("cell")^(@)=E_("cathode")^(@)-E_("anode")^(@)=0.15=1.36V` |
|
| 995. |
How is mutual inductance of a pair of coils affected when (i) separation between the coils in increased, (ii) the number of turns of each coil is increased , (iii) a thin iron sheet is placed between the two coils, other factors remaining the same ? Explain your answer in each case. |
|
Answer» (i) As, `phi = MI`, with the increase in the distance between the coils the magnetic flux linked with the stationary coil decreases and hence the mutual inductance of the two coils will decrease. (ii) Mutual inductance of two coils can be found out by `M = mu_(0) n_(1) n_(2) AI, i.e., M alpha n_(1) n_(2)`, so with the increase in number of turns mutual inductance increases. |
|
| 996. |
Find the differential equation representing the family of curves `y=ae^(bx+5)`, where a and b are arbitrary constants. |
|
Answer» `y=ae^(bx+5)` `(dy)/(dx)=ae^(bx+5)xxb` `(d^2y)/(dx)^2=ab^2e^(bx+5)=bdy/dx=(dy/dx)^2xx1/y` |
|
| 997. |
How is repetitive/satelite DNA separated from bulk genomic DNA for various genetic experiments? |
| Answer» Satellite DNA is separated from bulk genomic DNA by density- gradient centrifugation technique. | |
| 998. |
Name the embryonic stage that gets implanted in the uterine wall of a human female. |
| Answer» Blastocyst: The blastocyst becomes embedded in the endometrium of the uterus. This is called implantation and it leads to pregnancy | |
| 999. |
a) Explain the phenomenon of double fertilization. b) Describe the post-zygotic events leading to implantation and placenta formation in humans. Mention any two functions of placenta. |
|
Answer» After triple fusion, the central cell becomes the primary endosperm cell (PEC). The primary endosperm nucleus gives rise to the endosperm, while the zygote develops into embryo. b) Function of Placenta: 1. Placenta secrets like human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens and progestogens that are necessary to maintain pregnancy. 2) Umblical cord, the structure that connects the placenta with the foetus, is formed. |
|
| 1000. |
Name the microbes that help production of the following products commercially : (a) Statin (b) Citric acid ( c) Penicillin (d) Butyric acid |
|
Answer» (a) Stain : Monascus purpureus. (b) Citric acid : Aspergillus niger. (c ) Penicillium : Penicillium notatum. (d) Butyric acid : Clostridium butulinum. |
|