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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.
| 2251. |
Question : What is DNA fingerprinting ? Mention its application. |
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Answer» Solution :DNA fingerprinting is a technique used to identify and ANALYZE the variation in VARIOUS individuals at the level of DNA. It is based on variability and polymorphism in DNA sequences. Application : (1) It is used in forensic science to identify potential crime suspects. (2) It is used to establish paternity and family relationships. (3) It is used to identify and protect the commercial VARIETIES of crops and LIVESTOCK. (4) It is used to find out the evolutionary history of an organism and trace out the linkages between groups of various ORGANISMS. |
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| 2252. |
Question : What is divergent evolution? Explain this with reference to the forelimbs of Cheetah and whales. |
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Answer» SOLUTION :The same structure developed along different directions due to adaptations to different needs is called divergent evolution. Forelimbs of cheetah and whales are meant for fast running and swimming as two different functions to perform respectively, but they have SIMILAR ANATOMICAL structure such as humerus, radius, ulna, carpals, METACARPALS and phalanges in their forelimbs. |
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| 2253. |
Question : Mendel's last law is |
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Answer» Segregation |
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| 2254. |
Question : What is dichogamy? |
| Answer» Solution :MATURATION of anther and stigma at DIFFERENT TIMES is CALLED DICHOGAMY. | |
| 2255. |
Question : What is diastema? |
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Answer» Solution :(i) In RABBIT, the gap between the incisors and premolar is called diastema. (ii) It helps in mastication and CHEWING of food in HERBIVOROUS ANIMALS. |
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| 2256. |
Question : What is diaphragm? |
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Answer» Solution :(i) The BODY is DIVISIBLE into thoracic CAVITY and abdominal cavity separated by a transverse PARTITION called diaphragm. (ii) It is the characteristic feature of mammals. (iii) Breathing movements are brought about by the movement of the diaphragm. |
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| 2257. |
Question : What is diapause and its significance ? |
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Answer» SOLUTION :Under unfavourable conditions many zooplankton species in lakes and ponds are KNOWN to enter DIAPAUSE, it is a STAGE of suspended DEVELOPMENT. It enables the animals to escape from unfavourable environmental situations. |
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| 2258. |
Question : What is diapedesis ? |
| Answer» Solution :Tissue damage and infection INDUCE leakage of VASCULAR FLUID,containing chemotactic signals like serotonin,histamine and prostaglandins.They influx phagocytic cells into the affected area.This phenimenon is CALLED diapedesis. | |
| 2259. |
Question : What is Diapause? |
| Answer» SOLUTION :It is a stage of SUSPENDED development, under unfavourable conditions by MANY ZOOPLANKTON in lakes and ponds. | |
| 2260. |
Question : What is diabetes mellitus? |
| Answer» SOLUTION :Diabetes MELLITUS is an endocrine disorder in which there is deficiency of NECESSARY amount of INSULIN, resulting in higher blood glucose values. | |
| 2261. |
Question : What is detritus? |
| Answer» Solution :DEAD PLANT REMAINS such as leaves, bark, flowers and dead remains of animals, INCLUDING faecal matter, constitute DETRITUS. | |
| 2262. |
Question : What is described as 'windows of the brain'? |
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Answer» Receptors |
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| 2263. |
Question : What is detritivour? Give example. |
| Answer» SOLUTION :The dead REMAINS of plants and ANIMALS and also FECAL matter, CONSTITUTE detritus. | |
| 2264. |
Question : What is deforestation? |
| Answer» SOLUTION :It is the process of removal DECREASE or DETERIORATION of the FOREST area. | |
| 2265. |
Question : Deforestation is |
| Answer» SOLUTION :The permanent removal, DECREASE or deteriorationof forests and WOODLANDS is CALLED deforestation. | |
| 2266. |
Question : What is decomposition ? Explain? |
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Answer» Solution :Earthworms are being REFERRED to as the farmer.s friend. This is so because they help in the breakdown of complex organic matter as well as in loosening of the SOIL. Similarly, decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and NUTRIENTS and the process is called decomposition. DEAD plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter constitute DETRITUS. |
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| 2267. |
Question : What is decomposition? |
| Answer» Solution :Breakdown of complex ORGANIC MATTER present in DETRITUS into INORGANIC SUBSTANCE by micro organism is called decomposition. | |
| 2268. |
Question : What is Darwinism? |
| Answer» Solution :DARWIN's Theory of ORIGIN of species by Natural selection which is based on several facts, observations and deductions, is POPULARLY known as DARWINISM. | |
| 2269. |
Question : What is Darwinian fitness ? |
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Answer» Solution :• Populations evolve to maximise their reproductive fitness in the habitat in which they live. • Under a particular set of SELECTION pressures, ORGANISMS evolve TOWARDS the most EFFICIENT reproductive strategy. • Some organisms breed only once in their life time(pacific salmon fish, bamboo). • Some reproduces many times during their life time(most birds and mammals) • Some organisms produce a large number of small sized offspring (oyster, pelagic fishes) • Some organisms produce small number of large sized offspring (birds, mammals) • Life history traits of organisms have evolved in relation to the constraints IMPOSED by the biotic and abiotic components of the habitat in which they live. |
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| 2270. |
Question : What is dark reaction of photosynthesis ? Describe C_(3) pathway ? |
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Answer» Solution :1. Dark reaction of pohotosynthesis : The lilght independent reaction of photosynthesis that occurs in stroma of chloroplast is called dark reaction of photosynthesis. 2. `C_(3)` Pathway : (1) Dr Melvin Calvin in the year 1954 discovered the path of carbon in photosynthesis, i.e.,sequence of reactions of `CO_(2)` fixation and synthesis of glucose from it using tracer technique, chromatography and autoradiography. (2) The sequence of reactions of `CO_(2)` fixation into glucose is called Calvin cycle. (3) Calvin and his co-worker Dr Bensen worked on Chlorella and Senedesmus (unicellular algae using `C^(14)` radioactive isotope of carbon) as tracer. (4) The first product in Calvin cycle of photosynthesis is a 3-carbon compound, i.e., PGA (phosphoglyceric acid). Therefore, this pathway of photosynthesis is called `C_(3)` pathway. (5) Calvin demonstrated and proved that the initial acceptor of carbon dioxide, i.e., RuBP is regenerated simultaneously with the synthesis of glucose. Calvin and his co-worker Dr Bensen where awarded a Nobel prize for this work in 1961. (6) The various steps of Calvin cycle are as follows : (i) Carboxylation : RuBP (Ribulose-1,-5 biphosphate) accepts atomospheric `CO_(2)` in the presence of the enzyme RuBP carboxylase (RUBISCO) and forms a 6-carbon unstable compound which soon splits into two molecules of 3-carbon compound called PGA (phosphoglyceric acid) in the presence of the same enzyme enzyme as shown under : `underset((5C))("RuBP")+underset((1C))(CO_(2)) overset(Mg^(+))underset("RuBISCO")to underset((6C))("unstable compound (i)")` `underset((6C))underset("compound")("Unstable")+H_(2)O overset(Mg^(++))underset("RuBISCO")to underset((3C))("2 molecules of 3-PGA")` (II) REDUCTION of PGA : The PGA thus formed undergoes photo-phosphorylation using ATP to form 1. 3-disphosphoglyceric acid which is reduced to PGAL (phospho-glyceraldehyde) by `NADPH_(2)` with the release of iP (inorganic phosphate). The reduction of PGA to PGAL can be SUMMARIZED as follows: `3PGA +ATPto 1`, 3 diphospohoglyceric acid `+`ADP 1, 3 diphosphoglycericacid `+ NADPH_(2) to 3PGAL + NADP + iP` Some molecules of PGAL undergo isomerization and form DHAP (dihydroxyacetone phosphate). This isomerization reaction is catalysed by the enzyme triose phosphate isomerase.  (iii) Synthesis of sugar : For the synthesis of one molecule of glucose six molecules of RuBP and six molecules of `CO_(2)`or 6 turns of Calvin cycle ar required. This shows that six turns of Calvin cycle are required for the synthesis of one molecule of glucose. Out of 12 molecules 2 molecules 2 molecules i.e., 1/6 part of PAGAL are utilized for thesynthesisof glucose. One molecule of PGAL and one molcecule of DHAP combine witheach other to form one molecule of fructose 1, 6-diphosphate as shown below : `underset((3C))(3PGAL)+underset((3C))(DHAP) tounderset((6C))("Fructose 1, 6-diphosphate")` Fructose 1, 6-diphosphate undergoes dephosphorylation to form fgructose-6-phosphate which on isomerization forms glucose-6-phosphate. Glucose-6-phosphate undergoes dephosphorylation to form glucose. Glucose thus formed is either utilized or stored as STARCH. (iv) Regeneration of RuBP : RuBP is regenerated through biochemical reactions called sugar phosphate interconversions. All the intermediate compounds, for example, erythrose-4-phosphate, xylulose-5-phosphate, ribose-5-phosphate, sedoheptulose-7-phosphate, etc. that arew formed during these reactions are sugar phosphates. Out of 12 molecules of PGAL 10 molecules are utilized for the regeneration of 6 molecules of RuMP (ribulose monophosphate) which on pohosphorylation form RuBP as shown below : ` "12 PGAL "to" 6 RuMP" ` ...(1) `"6 RuMP" + "6 ATP" to "RuBP" ` ...(2) Thus RuBPwhich is necessary for the reduction of `CO_(2)` is regenerated to keep the process going. |
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| 2271. |
Question : What is dark reaction in photosynthesis ? Describe C_(3) Pathway. |
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Answer» Solution :DarkReaction : 1. This is the second phase of photosynthesis in which`CO_(2)` is fixed or reduced to glucose. It occurs in the stroma of chloroplast. 2. It is independent of light (does not require direct light) hence called dark reaction. 3. The products of light reaction namely, ATP and `"NADPH"_(2)` are used here. 4. The presence of dark reaction was first established by Blackman hence also called "Blackman's reaction". `6CO_(2)+12"NADPH"_(2)+12"H"_(2)"O"+18"ATP"toC_(6)H_(12)O_(6)+12"NADP"^(+)+18"ADP"+18" Pi"` Calvin Cycle (`C_(3)` Pathway): 1. Dr. MelvinCalvin in 1954 discovered the correct "path of carbon" in photosynthesis i.e.sequence of biochemical reactions of `CO_(2)` fixation into glucose. 2. He carried out experiments on unicellular green algae like Chlorella and Scenedesmus, and used radioactive ISOTOPE of carbon, `C^(14)` as a tracer. The biochemical reactions leading to synthesis of glucose take place in cyclic manner are final product, glucose is produced in 90 seconds. 4. The initial accepter is regeneratedso that it can accept `CO_(2)` again and keep the process going. 5. The first stable product is a 3-carbond compound, hence, Dr. Calvin called it `C_(3)` cycle, or `C_(3)` pathway, but it is more popularly known as Calvin cycle or Calvin-Benson cycle.  The cycle involves the following three main steps : 1. Carboxylation 2. Reduction. 3A. Synthesis 3B. REGENERATION. 1. Carboxylation : Atmospheric `CO_(2)` is accepted by a 5-carbon compound called Ribulose-1-5-di-phosphate (RuDP) or Ribulose-1-5 bisphosphate (RuBP) in presence of enzyme RuDP carboxylaseor RuBP carboxylase (RuBisCO) to from a 6-carbon unstable compound. Immediately it splitsbyhydrolysis into two molecules of 3-carbon compound called phosphoglyceric acid (PGA), in thepresenceof same enzyme. `underset((5C))(RuBP)+underset(("IC"))("CO"_(2))underset("RuBP Carboxylase")overset("MG"^(+))tounderset((6C))("unstable compound")` `underset((6C))("Unstable")" compound"+H_(2)Ounderset("RuBP Carboxylase")overset("Mg"^(++))tounderset((3C))(2,3"PGA")` 2. Reduction: (Utilisation of Assimilatory Power) The Phosphoglyceric acid molecules are first phosphorylated by using ATP to produce 1, 3 di-phosphoglyceric acid which is then reduced using `"NADPH"_(2)` to produce phospho-glyceraldehyde (PGAL) and inorganic phosphate is released. `3"PGA"+"ATP"to1,3" di-PGA"+"ADP"` `1,3" di-PGA"+"NADPH"_(2)to3"PGAL"+"NADP"+"iP"` Some part of 3PGAL is converted into its isomer Dihydroxyacetone phosphate (DHAP) in the presence of enzyme triose-phosphate isomerase. 3A. Synthesis: For the synthesis of one glucose molecule, six turns of Calvin cycle are required or six molecules of RUBP and six molecules of `CO_(2)` are required. `1//6` part of PGAL i.e. out of 12 molecules, 2 are used for synthesis of glucose. One moleculeof PGAL and one molecule of DHAP combine together to from one molecule of fructose 1, 6-dephosphate. `underset((3C))(3"PGAL")+underset((3C))("DHAP")tounderset((6C))("Fructose 1, 6-diphosphate.")` By dephosphorylation it producesfructose-6-phosphate which when isomerizes intoglucoss-6-phosphate. Glucose-6-phosphate loses a phosphate group (dephosphorylation) to produce glucose. Glucose is either utilized or stored as starch. 3B. Regeneration : (a) RUBP gets regenerated through several biochemical reactions. These reactions are called sugar phosphate interconversions. (b) All the compounds/intermediates formed are sugar phosphates, for example, erythrose-4-phosphate (4-C), xylulose-5-phosphate (5-C), ribose-5-phosphate (5-C) sedoheptulose-7-phosphate (7-C) etc. (c) 5/6 part PGAL, i.e., out of 12 molecules, remaining 10 molecules are used for regeneration of 6 molecules of ribulose mono-phosphate (RuMP). (d) RuMP is phosphorylated to RuBP using ATP. (e) For regeneration of 6 RuBP, 6 ATPs are required. (f) Thus the initial acceptor of `CO_(2)` gets regenerated and keeps the process going (`12"NADPH"_(2)` and 18 ATP are required for synthesis of one glucose molecule). `C_(3)` Plants : (g) Most of the plants fix `CO_(2)`through Calvincycle and are called `C_(3)` plants. (h) RuBisCO is thermolabile and requires higher concentration of `CO_(2)` for its activity. (i) At high temperature the stomata close partially so that availability of `CO_(2)` falls. (J) At high temperature and at low `CO_(2)` concentration, RUBPcarboxylase, (i.e., RuBisCO-Ribulose Bis-phosphate Carboxylase Oxygenase), functions as oxygenase and brings about oxidation of RuBP instead of carboxylation. (k) Due to this a considerable (approximately `25%`) part of photosynthetically fixed `CO_(2)` goes back to atmosphere. (l) This is called photorespiration. |
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| 2272. |
Question : What is cytoplasmic male sterility ? |
| Answer» Solution :In Sorghum vulgare (PEARL maize) , the GENE located for the STERILITY pollen are located in the mitochondrial DNA.This PHENOMENON is called as cytoplasmic male sterility. | |
| 2273. |
Question : Cryptorchidism is |
| Answer» Solution :FAILURE of the TESTIS to DESCEND from abdomen into SCROTUM which leads to sterility is CALLED cryptorchidism. | |
| 2274. |
Question : What is cybrid? |
| Answer» Solution :The fusion product of PROTOPLASTS without NUCLEUS of DIFFERENT cells is called a CYBRID. | |
| 2275. |
Question : What is cultural eutrophication? Explain the stages involved in eutrophication. |
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Answer» Solution :Pollutants from man.s activities like effluents front the industries and homes can radically accelerate the aging process of a lake. This phenomenon is CALLED cultural or accelerated eutrophication. Nitrates and phosphates present in sewage, agricultural and industrial WASTES are the prime contaminants which act as plant nutrients. They over stimulate the growth of algae causing scum and unpleasant ODOUR and robbing the water of dissolved oxygen that is important to AQUATIC LIFE. Other pollutants flowing into lake, poison the whole population of fish whose decomposing remains further depletes the water.s dissolved oxygen content and the lake laterally chokes to death. |
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| 2276. |
Question : What is cumulus oophorus? |
| Answer» Solution :The EGG with its all SURROUNDING membranes is CALLED cumulus oophorus. | |
| 2277. |
Question : What is cultural or Accelerated Eutrophiction ? |
| Answer» Solution :Eutrophication TAKES PLACE by the human activity. Effluents from the indusries and homes can radiacally accelerate the ageing process. This phenomena is known as Accelerated Eutrophication or CULTURAL Eutrophication. | |
| 2278. |
Question : What is cultural eutrophication ? |
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Answer» SOLUTION :ACCELERATED or cultural eutrophication occurs due to draining of sewage and run off agricultural fields and industries into the water bodies. It causes PROFUSE GROWTH of blue-green algae which imparts characterstic colouration to water. It radically accelerates the aging PROCESS |
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| 2279. |
Question : What is cry protein? |
| Answer» Solution :Cry proteins are a LARGE family of crystalline toxins produced by Bacillus thuringiensis. They are highly specific but COLLECTIVELY they TARGET a DIVERSE range of INSECTS and nematodes, | |
| 2280. |
Question : What is cryopreservation? Mention how it is used in conservation of biodiversity |
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Answer» Solution :It is a technique to preserve gametes for long period in VIABLE and FERTILE condition at very low temperature e.g. at - `196^@C`in liquid NITROGEN -It is used to preserve gametes of threatened SPECIES |
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| 2281. |
Question : Whatis cryopreservation ? |
| Answer» SOLUTION :It refers to theplacing the cellsor tissueor SEEDS in liquid nitrogen of ` - 196^(@)C` forindefinite period of time WITHOUT losingtheir viability . | |
| 2282. |
Question : What is crossing over? In which stage of cell division it takes place? |
| Answer» Solution :Crossing over is the process of exchange of genetic material or SEGMENTS between non-sister chromatids of two homologous chromosomes.In PACHYTENE of MEIOSIS I,crossing over OCCURS. | |
| 2283. |
Question : What is cross - pollination ? What are its types ? |
| Answer» Solution :CROSS - Pollination REFERS to the TRANSFER of pollens on the stigma of another flower . The cross- pollination is of two TYPES:(I) GEITONOGAMY and (ii) Xenogamy. | |
| 2284. |
Question : What is cross-breeding ? Name a new breed developed by crossing Bikaneri ewes and Marino rams |
| Answer» Solution :SUPERIOR MALES of ONE BREED are mated with Superior females of ANOTHER breed. "Hisrdale" | |
| 2285. |
Question : Define criss-cross inheritance. |
| Answer» SOLUTION :Inheritance of GENES frome a MALE parent to FEMALE child and then to male grandchild or female parent to male child and then to female grandchild. E.g., X-linked gene inheritance. | |
| 2286. |
Question :What is CRISPR - Cas 9 ? |
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Answer» Solution :Genome editing or gene editing is a group of TECHNOLOGIES that has the ability to change an organism's DNA and allow genetic meterial to be ADDED , removed , or altered at PARTICULAR locations in the genome . (ii) A recent one is known as CRISPR-Cas9, which is short from of Clustered Regularly Interspaced short Palindromic Repeats and CRISPR- ASSOCIATED protein 9. (iii) It is faster , cheaper, more accurate , andmore efficient then other existing genome editing method . |
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| 2288. |
Question : What is correct to say about the hormone action in human? |
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Answer» Glucagon is SECRETED by `beta` cells of islets of Langerhans and stimulates glycogenolysis |
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| 2289. |
Question : What is correct pair ? |
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Answer» CryIAb-Cotton BOLLWORMS |
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| 2290. |
Question : What is correct for transducers: |
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Answer» They converts SOLAR ENERGY into chemical energy |
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| 2291. |
Question : What is correct for stages of Puccinia? |
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Answer» Telia and aecia on wheat |
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| 2292. |
Question : What is correct about root pressure ? |
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Answer» PROVIDES a modest push in the over all process of water transport |
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| 2293. |
Question : What is correct about mammalian palate 1 Primary structure. 2.Parallel to original roof of mouth cavity 3.Tertiary stucture 4. Secondary structure |
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Answer» 1,2,3 CORRECT |
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| 2294. |
Question : What is correct |
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Answer» Foetal heart is FORMED in SECOND month |
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| 2295. |
Question : What is corpus luteum? What is its function? |
| Answer» Solution : YELLOW coloured body DEVELOPED by the RUPTURED Graafian follicle is KNOWN as corpus LUTEUM. | |
| 2296. |
Question : What is corpus albicans? |
| Answer» Solution :In the absence of fertilization, the corpus LUTEUM degenerates COMPLETELY and leaves a scar tissue called corpus albicans. It also initiates the DISINTEGRATION of the endometrium LEADING to menstruation, marking the next cycle. | |
| 2297. |
Question : What is corpus albicans ? |
| Answer» Solution :In the absence to fertilization , the corpus luteum degenerates COMPLETELY and LEAVES a scar TISSUE CALLED corpus ALBICANS . It also initiates the disintegration of the endometrium leading tomenstruation , marking the next cycle . | |
| 2298. |
Question : What is continuous variation? |
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Answer» Solution :(i) The VARIATION may be DUE to the combining EFFECTS of environmental and genetic factors. (II) Inheritance of phenotype is determined by the combined effects of MANY genes,(polygenes) and enviromental factors. (iii) It is also known as quantitative inheritance. Example: Human height and skin color. |
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| 2299. |
Question : What is contact inhibition?How it is related to tumours growth? |
| Answer» Solution :NORMAL cells show a property called contact inhibition ,which INHIBITS uncontrolled growth.Cancer cells do not have this property .As a result ,cancerous cells DIVIDE continuosly giving RISE to mass of tissue called tumours. | |
| 2300. |
Question : What is contact inhibition? Mention the types of tumours. |
| Answer» Solution :NORMAL cells show a property called contact inhibition by virtue of which contact with other cells inhibit their UNCONTROLLED growth. Cancer cells appear to have lost this property. As a RESULT of this, cancerous cells just continue to divide giving rise to masses of cells called tumours.Tumours are of TWO TYPES (a) Benign (b) Malignant tumours | |