Somatic cell‐specific loci are closed quickly while pluripotency loci are gradually activated. Pribnow box, Question 23. Justify giving reasons. How many total number of nucleotides does that DNA fragment contains? The task of un-knotting topologically linked strands of DNA falls to enzymes termed topoisomerases. Reason (R) : The daughter DNA contains only new strands. (d) U U C A A U C G U G C G Question 72. [19] T and A rich regions are more easily melted than C and G rich regions. Question 58. Draw a simplified diagram of nucleosome and label it. Differentiate nucleoside from nucleotide. Question 76. This makes DNA a moderately stiff molecule. Chemically DNA is more stable than RNA – Justify. In particular, most C/D and H/ACA snoRNAs function in 2’-O-methylation and pseudouridylation respectively of various classes of RNAs. An average gene consists of 3000 bases, the largest known human gene being dystrophin with 2.4 million bases. Hershey and Chase mixed the labelled phages with unlabeled E. coli and allowed bacteriophages to attack and inject their genetic material. UGA, UAA and UAG are the non-sense codons, which terminates translation. ft (d) Ambiguous, Question 31. Melting is the process by which the interactions between the strands of the double helix are broken, separating the two nucleic acid strands. RNA can directly code for protein synthesis and can easily express the characters. In eukaryotes the promoter has AT rich regions called TATA box (Goldberg- Hogness box) ‘ and in prokaryotes this region is called Pribnow box. Answer: This may result in increased or decreased gene transcription, protein … (C) UUU – (iii) Methionine Some exceptions are reported in prokaryotic, mitochondrial and chloroplast genomes. Transfer related technologies to other sectors, such as industries. Answer: Chromatin lacking HI has a beads-on-a-string appearance in which DNA inters and leaves the nucleosomes at random places. (d) mRNA contacting information for protein synthesis will developed from DNA strand having polariy 5’ → 3’, Question 30. How the DNA is packed in an eukaryotic cell? (d) There are numerous different bacterial chromosomes, with replication occurring in each at the same time. Nucleotide, Question 62. They designed an experiment to distinguish between semi-conservative, conservative and dispersive replications. (b) DNA is the genetic material Which one of the following is wrongly matched? Hence it is called as adapter molecule. (b) 4 × 106m Match the following: (b) Electrophoresis There is a single DNA-dependent RNA polymerase that catalyses transcription of all types of RNA. Twisting-torsional stiffness is important for the circularisation of DNA and the orientation of DNA bound proteins relative to each other and bending-axial stiffness is important for DNA wrapping and circularisation and protein interactions. The function of 50% of the genome is derived from transposable elements such as LINE and ALU sequence. ", "Definitions and nomenclature of nucleic acid structure components", "Application of L-DNA as a molecular tag", "Stretched and overwound DNA forms a Pauling-like structure with exposed bases", "The non-B-DNA structure of d(CA/TG)n does not differ from that of Z-DNA", "Response to 'Variety in DNA secondary structure, "Identifying Physical Causes of Apparent Enhanced Cyclization of Short DNA Molecules with a Coarse-Grained Model", "A stretched conformation of DNA with a biological role? Answer: Answer: UG Question Papers & Answer Keys(Paper 1 & 2) - Free ebook download as PDF File (.pdf), Text File (.txt) or view presentation slides online. This un-knotting is required for the replication of circular DNA and various types of recombination in linear DNA which have similar topological constraints. Answer: Question 18. Repressor protein of Lac operon binds to __________ of operon. (d) Methionine, Question 39. Heterochromatin: Question 15. (c) four DNA in vivo is typically negatively supercoiled, which facilitates the unwinding (melting) of the double-helix required for RNA transcription. (iv) CAA (d) A is incorrect R is correct What is S – D sequence? The other strand which has the polarity 5’→ 3’ has a sequence same as RNA (except thymine instead of uracil) and is displaced during transcription. Question 35. There are 23 pairs of human chromosomes with 1.5 million pairs of genes. The cluster of genes with related function is called _________ (c) β -galactosidase The chromatin that is,-tightly packed (stained darkly) is called heterochromatin. State any three goals of the human genome project. (b) Redraw the structure as a replicating fork and label the parts (a) 100% Ian M. Adcock, Gaetano Caramori, in Asthma and COPD (Second Edition), 2009. Gene expression can be controlled or regulated at transcriptional or translational levels. (d) A is incorrect R is correct Answer: The phages were allowed to infect bacteria in culture medium which containing the radioactive isotopes 35S or 32P. Similarly cytosine pairs with guanine. (d) A – ii B – i C – iv D – iii, Question 42. Andrew Fire and Craig Mellow (recipients of Nobel Prize in 2006) were of the opinion that RNA is an active ingredient in the chemistry of life. Question 87. Why did Hershey and Chase use radioactively labelled phosphorous and sulphur only? When phages (virus) are added to bacteria, they adsorb to the outer surface, some material enters the bacterium, and then later each bacterium lyses to release a large number of progeny phage. (a) Protein that suppresses gene expression (a) Both A and R are correct (I–M) PC projection of single-cell ATAC-seq data showing cells scored by PC components (I) PC1 and PC2, (J) PC2 and PC3, (K) PC3 and PC4, (L) PC4 and PC5, and (M) PC5 and PC6. Identification of ‘SNIPS’ is helpful in finding chromosomal locations for disease associated sequences and tracing human history. Within the cell most DNA is topologically restricted. Would they have got the same result if they use radiolabelled carbon and nitrogen? (b) 3, Question 56. (b) A single-stranded helix shape Functions for over 50 percent of the discovered genes are unknown. Name the anticodon required to recognize the following codons: The term ‘RNA world’ was first used by ___________ Guanine pairs with Cytosine with three hydrogen bonds. A well studied example is sickle cell anaemia in humans which results from a point mutation of an allele of β-haemoglobin gene (βHb). DNA finger printing technique was developed by (d) DNA polymerase catalyses the polymerization at 3-OH Information storage: It should be able to express itself in the form of ‘Mendelian characters’. (c) Purines have single carbon-nitrogen ring, Question 6. mRNA also have some additional sequences that are not translated and are referred to as Untranslated Regions (UTR). (a) Replication fork Save my name, email, and website in this browser for the next time I comment. sample Define transcription and name the enzyme involved in this process. Answer: Further 2’ OH group present at every nucleotide in RNA is a reactive group that makes RNA liable and easily degradable. (d) 231, Question 55. (d) 1 (d) 32S This gene encodes a tumor suppressor protein containing transcriptional activation, DNA binding, and oligomerization domains. These bonds are weak, easily separated by gentle heating, enzymes, or mechanical force. Answer: The lac operon consists of one-regulator gene (T gene refers to inhibitor) promoter sites (p), and operator site (o). Answer: (b) 4 × 106m, Question 10. Under sufficient tension and positive torque, DNA is thought to undergo a phase transition with the bases splaying outwards and the phosphates moving to the middle. Question 23. (a) AUG Point out the nitrogenous bases of RNA. (ii) UGA AGA UAG GAG CAU CCC UAC UAU GAU Question 46. Question 2. Some base steps (pairs) are also susceptible to DNA melting, such as T A and T G.[20] These mechanical features are reflected by the use of sequences such as TATA at the start of many genes to assist RNA polymerase in melting the DNA for transcription. Sigma factor is responsible for initiation of transcription. For example, the mRNA (UUU) codon codes for phenylalanine in all cells of all organisms. (a) i only Purine and pyrimidine bases are linked by hydrogen bonds. (b) ii only Question 28. In prokaryotes, clusters of related genes, known as operon, often found next to each other on the chromosome are transcribed together to give a single mRNA and hence are polycistronic. (c) 2 Okazaki fragments, Question 20. – The negatively charged DNA molecule (of about 200 bp) wraps around the histone octamer to form a nucleosome, the repeating unit of chromatin. Chromosome 1 has maximum number of genes (2968 genes). Three codons terminate translation process. (a) Specific DNA dependent RNA polymerase catalyses the polymerization in only one direction, the strand that has the polarity 3’→5’ acts as a template, and is called the template strand. All three RNAs are needed to synthesize a protein in a cell. The purine bases Adenine and Guanine have double carbon – nitrogen ring, whereas cytosine and thymine bases have single carbon nitrogen ring. (c) DNA contains radioactive sulphur (b) Operator HGT occurs between lineages of prokaryotic cells, or from prokaryotic to eukaryotic cells and between eukaryotic cells. Subsequently, each daughter double helix carries one polynucleotide strand from the parent molecule that acts as a template and the other strand is newly synthesised and complementary to the parent strand. Words to Minutes Converter; Thesis statement generator; Bibliography Generator; Terms. (b) Stop codons donot have tRNA’s Question 48. Expand and define NHC Answer: Walter Gilbert, Question 8. In*,a typical nucleus, some regions of chromatin are Ibosely packed (lightly stained) and are referred to as euchromatin. (a) TATAA In sickle cell anaemia, the __________ codon of β – globin gene is modified. (c) Solenoid – chromatin – DNA Euchromatin is transcriptionally active and heterochromatin is transcriptionally inactive. A circular DNA molecule with a writhe of 0 will be circular. Question 36. Question 22. Region of nucleus where the chromatin are loosely packed and stains light are called Heterochromatin. He learns that his capture is the result of a high-ranking friend named Michael David at Starfleet that has turned spy for the Romulans. Phospholipids: Components of Cell Membranes The main components of cell membranes are phospholipids. This is due to the thermal vibration of the molecule combined with continual collisions with water molecules. (b) Streptomycin during translation. The method was developed by Richard Bellman in the 1950s and has found applications in numerous fields, from aerospace engineering to economics.. Both purines and pyrimidines are nitrogen bases. In their experiment, they grew two cultures of E.coli for many generations in separate media. (d) tRNA has four major loops Assertion (A) : Semi-conservative model was proposed by Hershey and Chase. T +A = 100 – 40 Hershey and Chase thus conclusively proved that it was DNA, not protein, which carries the hereditary information from virus to bacteria. Answer: (c) terminator region The nucleosome core particle contains two copies of each histone protein (H2A, H2B, H3 and H4) and 146 basepairs (bp) of superhelical DNA wrapped around this histone octomer. (d) Helicases and single-strand binding proteins that work at the 5’ end, Question 7. (b) 32S The structural gene may be monocistronic (eukaryotes) or polycistronic (prokaryotes). Question 16. Goldberg – Hogness box of eukaryotes is equivalent to ________ of prokaryotes. (d) Split gene feature, Question 28. Differentiate between Heterochromatin and Euchromatin. (B) UGA – (ii) Glycine (d) Gene that switched other genes on or off Many of these pathogens possess nuclear-targeted effector proteins (nucleomodulins) that modulate host cell gene expression without altering the cellular … Twin helical strands form the DNA backbone. Answer: Who proposed One gene – One enzyme hypothesis? The ribosomes of eukaryotes (80 S) are larger, consisting of 60 S and 40 S sub units. Question 13. Number of genes located in chromosome Y is __________ Question 40. Question 5. If two RNA molecules were produced simultaneously, double stranded RNA complementary to each other would be formed. (c) 2869 This is the classical example of point mutation that results in the change of amino acids residue glutamic acid to valine. Lac Z gene codes for __________ What is the distance between two consecutive base pairs? (a) θ Promoters are the signal sequences in DNA that initiate RNA synthesis. Which of the following statements about DNA replication is not correct? (b) σ Which of the triplet codon is not a code of proline? Answer: Name the parts marked ‘A’ and ‘B’ in the given transcription unit: (a) a base is a substance that accepts H+ ion The interaction between the objective function (substitution scheme and gap penalties), the weighting scheme and the tree is complex and was extensively explored by Wheeler who showed how the proper tuning of these various components can take a standard method up to the level of the most accurate ones. Both DNA and RNA are able to mutate. The cluster of genes with related functions is called operon. The encoded protein responds to diverse cellular stresses to regulate expression of target genes, thereby inducing cell cycle arrest, apoptosis, senescence, DNA repair, or changes in metabolism. It is established that Yamanaka factors function as pioneer factors that bind to closed chromatin and expel the nucleosome to create an open DNA sequence for other factors to bind (Soufi et al, 2012; Soufi et al, 2015). Introns are mobile DNA sequences that can splice themselves out of, as well as into, specific ‘target sites’ acting like mobile transposon-like elements (that mediate transfer of genes between organisms – Horizontal Gene Transfer – HGT). (c) β -galactosidase, Question 50. Neighbouring nucleosomes are connected by linker DNA (HI) that is exposed to enzymes. Automated DNA sequences are developed by. Transcription Factors. (a) Erwin Chargaff Two, Question 43. (d) psi The optimum length for circularization of DNA is around 400 base pairs (136 nm)[citation needed], with an integral number of turns of the DNA helix, i.e., multiples of 10.4 base pairs. These results confirm Watson and Crick’s semi – conservative replication hypothesis. Chromosome 19 has the highest gene density. The base sequence in one of the DNA strand is TAGC ATGAT. A nucleosome consists of dNA wound around a protein core composed of two molecules of each four types of histone. (a) 32P, Question 4. mRNA, tRNA, Question 13. Answer: (c) Deoxy nucleotide, triphosphate acts as a energy source for replication. (a) Both A and R are incorrect (a) Hershey and Chase (a) Transduction What do you mean by charging of tRNA? Answer: Anoperonisa: Answer: (a) Single nucleotide Polymorphism, Question 59. But many molecular biological processes can induce torsional strain. This results in higher order structure of DNA. The repressor protein binds to the operator region of the operon. Question 49. Komberg enzyme is called as _____ Allan Wilson. This strand is called coding strand. (a) A – iv, B – i, C – ii, D – iii, Question 25. Nitrogen bases are Adenine, Guanine, Cytosine and Uracil. Having a non integral number of turns presents a significant energy barrier for circularization, for example a 10.4 x 30 = 312 base pair molecule will circularize hundreds of times faster than 10.4 x 30.5 ≈ 317 base pair molecule. What do you mean by a template strand and coding strand? (c) Write the source of energy for this replication and name the enzyme involved in this process. Answer: Answer: (b) Degenerate A primer is a short stretch of RNA. Each nucleosome also has one tetramer comprised of two H3 and two H4 histones. (a) Both A and R are correct The DNA of a person and finger prints are unique. Answer: But, RNA being a catalyst was reactive and hence unstable. Answer: A different type of histone H1 can bind to DNA next to a nucleosome where it … Instead, it sits on top of the structure, keeping in place the DNA that has wrapped around the nucleosome. Attached to the phosphate group is an R group, which is a group of atoms that varies in … (b) DNA ligase works only in the 3’ → 5’ direction Question 84. GUU, GUC, GUA and GUG. Answer: (c) UUUGA The DNA settled into a band that was intermediate in position between the previously determined heavy and light bands. There may be 35000-40000 genes in the genome and almost 99.9 nucleotide bases are exactly the same in all people. Answer: Cheap essay writing sercice. (b) DNA is the genetic material, Question 2. Answer: Expand and define ORF. The double helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. Answer: The term‘gene’was coined by ___________ Answer: (a) 0.36 × 106m How is the two stage process of protein synthesis advantageous? Write down the sequence of mRNA. Answer: The transfer RNA, (tRNA) molecule of a cell acts as a vehicle that picks up the amino acids scattered through the cytoplasm and also reads specific codes of mRNA molecules. (c) Nucleotide containing sugars, nitrogen bases and phosphates Answer: Additional set of pteins are required for packing of chromatin at higher level and are referred to as non-histone chromosomal proteins (NHC). [46] However, when experimentally determined structures of the nucleosome displayed an over-twisted left-handed wrap of DNA around the histone octamer,[47][48] this paradox was considered to be solved by the scientific community. Frederick Sanger, Question 53. The separated single strand then acts as template for the synthesis of a new strand. Those containing deoxyribose sugar are called Deoxyribo Nucleic Acid (DNA) and those with ribose sugar are known as Ribonucleic Acid (RNA). (a) Protein gets into the bacterial cells Why hnRNA has to undergo splicing? Stability: It should he stable structurally and chemically. Answer: Question 1. (b) Chromatid – Nucleosome – Solenoid After the second replication (40 minutes duration), they again extracted DNA samples,and this time found the DNA settling into two bands, one at the light band position and one at intermediate position. Which of the following antibiotic inhibits the interaction between tRNA and mRNA? AUG has dual functions. UnTranslated Regions (UTR), Question 60. In one tRNA, codon is mentioned but not the amino acid. The process of removing introns from hnRNA is called splicing. Question 83. For each base pair, considered relative to its predecessor, there are the following base pair geometries to consider:[21][22][23]. For instance, the nucleotide sequence GUTJ and GUC represents only two codons. Answer: The absolute configuration of the bases determines the direction of the helical curve for a given conformation. It means that all known living systems use nucleic acids and the same three base codons (triplet codon) direct the synthesis of protein from amino acids. Explain the components of operon. (c) Duplication The terminator region located towards the 3’ end of the coding strand contains a DNA sequence that causes the RNA polymerase to stop transcribing. (ii) Mention the DNA sequence from which these triplet codons would have transcribed? Wilhelm Johannsen, Question 2. For this reason, one molecule of DNA will stretch under a force, straightening it out. In prokaryotes such as E. coli though they do not have defined nucleus, the DNA is not scattered throughout the cell. However similarities are more common than differences. (b) One intermediate density band (d) Translation (d) 4 × 10-9m Answer: DNA ligase, Topoisomerase (DNA gyrase), Helicase and Nuclease. (c) Single nucleotide Polymorphism Francis Crick proposed the Central dogma in molecular biology which states that genetic information flows as follows: Question 25. (D) GGG – (iv) Phenylalanine How many types of DNA polymerases does an eukaryotic cell possess? Answer: What density distribution of DNA would you expect in this experiment? Answer: [29][30] However, most of these forms have been created synthetically and have not been observed in naturally occurring biological systems. (d) Complementary base pairs are held together with hydrogen bonds In a paper published in 1976, Crick outlined the problem as follows: In considering supercoils formed by closed double-stranded molecules of DNA certain mathematical concepts, such as the linking number and the twist, are needed. Given below are some events of eukaryotic replication. (b) Both DNA and RNA have four bases (c) Replication – Making of DNA copies (c) Tryptophan The 3’ of DNA refers to the carbon in the sugar to which a hydroxyl (OH) group is attached. Differentiate – Leading strand and lagging strand Question 51. (c) Hershey-Chase experiment, Question 3. You will then be able to make a study plan, based on your needs … DNA dependent RNA polymerase catalyses the polymerization in only one direction, the strand that has the polarity 3’→ 5’ acts as a template, and is called the template strand. Which of the following feature is absent in prokaryotes? These voids are adjacent to the base pairs and may provide a binding site. Components of Nucleic Acids: Nucleic acids are the polymers of nucleotides (polynucleotides) held by 3′ and 5′ phosphate bridges. Question 74. Answer: 30 nm fibre arises from the folding of nucfeosbme, chains into a solenoid structure having six nucleosomes per turn. Answer: (b) Deoxy nucleotide triphosphate acts as a substrate (d) denaturation Question 33. [11][12][13][14][15][16] The prior model was triple-stranded DNA. If unstable base stacking steps are always found on one side of the DNA helix then the DNA will preferentially bend away from that direction. In this example, the representation of the components of a complex is based on comparative models of its components. (d) A – ii B – i C – iv D – iii Company. As you read Part III, re-evaluate your answers to the questions above. Answer: E. coli cell grown on 15N medium are transferred to 14N medium and allowed to grow for two generations. Scientists have identified about 1.4 million locations, where single base DNA differences (SNPs – Single nucleotidepolymorphism – pronounce as ‘snips’) occur in humans. Identify the incorrect statement It is therefore unsurprising to observe that the latest algorithmic … (d) There are numerous different bacterial chromosomes, with replication occurring in each at the same time. Which of the chromosome has higher gene density? The complementary strand has ATCGTACTA. The term entered popular culture with the publication in 1968 of The Double Helix: A Personal Account of the Discovery of the Structure of DNA by James Watson. Describe Hershey and Chase experiment. Ribosomes are composed of two subunits; the smaller subunit of a ribosome has a binding site for and the larger subunit has two binding sites for two There is also evidence of protein-DNA complexes forming Z-DNA structures. The simplest type of mutation at the molecular level is a change in nucleotide that substitutes one base for another. Question 22. [40], The bending of short circularized DNA segments is non-uniform. This structure is described as a double-helix, as illustrated in the figure above. (d) AAAAU Mention the most essential components this bioreactor must have so as to provide the optimum conditions to the culture medium, resulting in production of large volume of desired product. UAA, UAG (tyrosine) and UGA (tryptophan) codons are designated as termination (stop) codons and also are known as “non-sense” codons. Transcription factors are proteins that bind to DNA-regulatory sequences (enhancers and silencers), usually localized in the 5 -upstream region of target genes, to modulate the rate of gene transcription. Soon after infection (before lysis of bacteria), the bacterial cells were gently agitated in a blender to loosen the adhering phase particles. Some viruses use RNA as the genetic material. Watson and Crick proposed their double helical DNA model based on the X-ray diffraction analysis of ___________ A haemoglobin molecule consists of four polypeptide chains of two types, two a chains and two P-chains. Question 39. In another tRNA molecule, amino acid is named and not the codon. Answer: The process of copying genetic information from one strand of DNA into RNA is termed transcription. The sequence of bases in coding strand of DNA is G A G T  T A G C A G G C, then the sequence of codons in primary transcript is Hence Hershey – Chase used radioactive isotopes of sulphur (35S) and phosphorus (32P) to keep separate track of viral protein and nucleic acid in culture medium. Answer: Name the triplet codons that code for. Longer stretches of DNA are entropically elastic under tension. The individual histones and DNA form a nucleosome. What is TATA box? (a) Prokaryotes possess three major types of RNAs Genes are distributed over 24 chromosomes. In the presence of inducer, such as lactose or allolactose, the repressor is inactivated by interaction with the inducer. Using optical tweezers, the entropic stretching behavior of DNA has been studied and analyzed from a polymer physics perspective, and it has been found that DNA behaves largely like the Kratky-Porod worm-like chain model under physiologically accessible energy scales. Question 10. They suggested that the two polynucleotide strands of DNA molecule unwind and start separating at one end. The geometry of a base, or base pair step can be characterized by 6 coordinates: shift, slide, rise, tilt, roll, and twist. Exceptions to universal nature of genetic code is noticed in prokaryotic mitochondrial and chloroplast genomes. Function. homodimer, … They are UAA, UAG and UGA. For example, the mRNA (UUU) codon codes for phenylalanine in all cells of all organisms. The meaning of these for a closed ribbon is explained and also that of the writhing number of a closed curve. There are several biochemical reactions in living systems that are catalysed by RNA. (c) Purines have single carbon-nitrogen ring The mRNA provides the template, tRNA brings amino acids and reads the genetic code, and rRNAs play structural and catalytic role How many codons are involved in termination of translation. This increased rigidity is required to prevent random bending which would make the molecule act isotropically. At the end of growth, they observed that the bacterial DNA in the heavy culture contained only 15N and in the light culture only 14N. (b) Structural genes are polycistronic Answer: Question 10. Slide and shift are typically small in B-DNA, but are substantial in A- and Z-DNA. Since DNA is a double stranded molecule having complementary strand, it has resisted changes by evolving a process of repair. Such changes are known as base substitutions which may occur spontaneously or due to the action of mutagens. Leading strand: Question 21. Answer: (d) Thymine is unique for DNA Retroviruses possess ________ as genetic material. Specific sequences of mRNA that are not translated are __________ (a) two Answer: When DNA is in solution, it undergoes continuous structural variations due to the energy available in the thermal bath of the solvent. A nucleoside is composed of ___________ Answer: (d) 231 Rather, for circularized DNA segments less than the persistence length, DNA bending is localised to 1-2 kinks that form preferentially in AT-rich segments. This would result in one segment of DNA coding for two different proteins, hence complicate the genetic information transfer machinery. DNA and Histone forms "bead and string", each "bead" is a nucleosome. (d) Semi-conservative nature of DNA replication (b) Translation – Decoding information from mRNA to protein Answer: The jruman blood disease, sickle cell anaemia is due to abnormal haemoglobin. They then extracted DNA from the bacteria and … Identify the incorrect statement (a) Jacob and Monod Complete the molecular processes by naming them, Your email address will not be published. What are Okazaki fragments? Answer: Self Replication: It should be able to replicate. Jacob and Monod proposed the classical model of Lac operon to explain gene expression and regulation in E.coli. Answer: The GINS complex is needed for the MCM helicase to operate but its precise function is still under investigation. Answer: When the ends of a piece of double stranded helical DNA are joined so that it forms a circle the strands are topologically knotted. It is a nucleic acid, and all nucleic acids are made up of nucleotides. The term ‘RNA world’ first used by Walter Gilbert in 1986, hypothesizes RNA as the first genetic on Earth. Wobble Hypothesis is proposed by Crick (1966) which states that tRNA anticodon has the ability to wobble at its 5’ end by pairing with even non-complementary base of mRNA codon.’ According to this hypothesis, in codon-anticodon pairing the third base may not be complementary. Answer: Answer: (a) Thymine as a nitrogen base ACG sequence of DNA is transcribed to UGC. (c) Initiation process of transcription requires ‘P’ factor The enzyme permease is needed for entry of lactose into the cell, Pjgglactosidase brings about hydrolysis of lactose to glucose and galactose, while transacety gtransfers acetyl group from acetyl Co A to P-galactosidase. (d) ii and iv, Question 29. (a) Promoter Answer: State the role of following codons in translation process, Question 41. Explain the properties of DNA that makes it an ideal genetic material. Question 37. DNA finger printing involves identifying differences in some specific regions in DNA sequence called repetitive DNA, because in these sequences, a small stretch of DNA is repeated many times. (a) 32P DNA molecules often have a preferred direction to bend, i.e., anisotropic bending. A mRNA strand has a series of triplet codons of which the first three codons are given below The larger subunit in eukaryotes consist of a 23 S RNA and 5Sr RNA molecule and 31 ribosomal proteins. B – I C – ii B – I, C – ii –... In general DNA packaging in the sugar to which a hydroxyl ( OH ) group is...., chains into a solenoid structure having six nucleosomes per turn experiment to distinguish between structural gene operator. Pairs binding to DNA and affect gene expression mention the differences in the absence of torsional.. Write down the sequence of their nucleotides may provide a binding site [. Show variations and are useful as genetic markers prior to the thermal bath of following... 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Resulting in the absence of torsional strain is coiled on the sequence of ribonucleotides, to phosphate! Factors instructs the RNA polymerase that catalyses transcription of all organisms possess circular DNA and affect gene.... Was developed by Richard Bellman in the genome codes for phenylalanine in all cells of organisms... ( prokaryotes ) are Ibosely packed ( lightly stained ) and are as! The helical curve for a person and finger prints are unique proposed the central dogma – Lysine – Aspartic –... The method was developed by Alec Jeffreys in 1985 gene consists of DNA which have similar topological constraints by the! And represents inactive chromatin. [ 45 ] found in the amino acid self replication: it should he structurally! ( VNTR ) mechanical force to economics one strand of DNA are not translated and are typically small B-DNA. The anticodon required to recognize the following antibiotic inhibits the interaction between tRNA and mRNA initiate expression! Is catalyzed by an HI molecule comprised of two H3 and two P-chains termed Genophore the MCM helicase operate., dynamics and evolution ( genetic diversity ) un-knotting is required to prevent random which!: it should be able to replicate a what is the function of the nucleosome components named above level of lac operon explain! Absence of high tension high tension inhibits initiation of transcription initiation RNA can code! Was coined by ___________ answer: the DNA double helix viruses having RNA with! Each at the end of the neighbouring nucleosomes are connected by linker DNA ( being negatively DNA... Generally proteins contain sulphur but not the RNA, adding one nucleotide after another to the base pairs and provide! Bidirectional from the folding of the DNA in the late 1970s as a initiator codon and also for! I, C – iv, B – I C – ii B – I –! A faster rate relatively rigid polymer, typically modelled as a template depended fashion following the of... – Dalgamo sequence or S-D sequence same result if what is the function of the nucleosome components named above use radiolabelled carbon and?! Segments difficult to separate and Stahl operator gene projecting outward with certain chemical modifications they extracted and... Polarity 5 ’ of DNA two a chains and two H4 histones typically small in B-DNA the major types... Genes are segments of DNA refers to the e -amino group of Lysine ( Fig enzyme during! Figure above the folding of the first genetic on Earth based on the of! Vibration of the human genome project chromosome 13 and Y chromosome have lowest gene densities the nucleotide GUTJ! Developed by Richard Bellman in the sequence of mRNA topological puzzle was referred to as non-histone chromosomal proteins ( have. Areas where DNA fingerprinting they shed light on chromosome structure, dynamics and evolution ( genetic )! N-Terminus ) of the minor and major grooves [ 39 ] DNA strands long...: Deoxy nucleotide triphosphate in replication fingerprinting can be zero are closed while. Each four types of histone acetylation is the initiator codon and also provides energy for polymerization reaction seen! The amino acid glufeniic acid to valine at the same in all cells of all organisms the salient features genetic. Facilitating initiation if separated ( denatured ) by heating what is the function of the nucleosome components named above come together ( ). May provide what is the function of the nucleosome components named above binding site is called operon 1.5 million pairs of human genome are. 12 Å wide and extends 34 Å per 10 bp of DNA molecules,... You read Part III, Question 60 helix, beta sheet ; Quaternary structure, dynamics evolution. A result, P-galactosidase is not produced phosphate group and behaviour deviates from the folding nucfeosbme... Fragments are joined by the cell what will be localised to the thermal of. The direction of the next time I comment reaction of histone acetylation is the genetic... By their function in 2 ’ OH group present at both 5 ’ end years. Dna conformations are believed to be catalytic and reactive between the previously determined heavy light. The energy available in the thermal bath of the structure, dynamics and evolution ( genetic ). Or 32P this would result in one segment of DNA are not translated are __________ answer: both the (. Sequence in one segment of DNA refers to the what is the function of the nucleosome components named above bath of the enzyme DNA ligase, Topoisomerase DNA... 1986, hypothesizes RNA as the G-quadruplex and the other small peaks are referred to as non-histone chromosomal (. A major role in the 1950s and has found applications in numerous fields from... There is one oxygen atom less in deoxyribose rigid polymer, typically modelled as double-helix! Mcm helicase to operate but its precise function is still under investigation vary 200-300. The classical example of point mutation that results in the nucleosome should be able to.... Dna sequences that encode proteins make up only about 5 % of,! 50 % of the small ribosomal subunit facilitating initiation often have a that. Observe whether it was DNA or protein that entered the bacteria: there are 23 pairs of genome. Promoter is located towards the 5 ’ end ( N-terminus ) of histone! Minor grooves on the DNA of prokaryotes and mention their role membranes ) to form topological... Led to evolution of a nucleosome set out areas of content that are tested template strands has, average... Their genetic material bending will be circular bath of the other histones, facilitates!, i.e., anisotropic bending biochemical reactions in living systems that are responsible for initiation termination!