Title 06. MOLECULAR BASIS OF INHERITANCE.pdf ✅

06. MOLECULAR BASIS OF INHERITANCE 1.) Which of the following statements is correct? a) Adenine pairs with thymine through two H-bonds. b) Adenine pairs with thymine through one H-bond. c) Adenine pairs with thymine through three H-bonds. d) Adenine does not pair with thymine. 2.) Purines found both in DNA and RNA are a) cytosine and thymine b) adenine and thymine c) adenine and guanine d) guanine and cytosine. 3.) The association of histone H1 with a nucleosome indicates that a) DNA replication is occurring b) the DNA is condensed into a chromatin fibre c) the DNA double helix is exposed d) transcription is occurring. 4.) In sea urchin DNA, which is double stranded, 17% of the bases were shown to be cytosine. The percentages of the other three bases expected to be present in this DNA are a) G 17%, A 33%, T 33% b) G 8.5%, A 50%, T 24.5% c) G 34%, A 24.5%, T 24.5% d) G 17%, A 16.5%, T 32.5%. 5.) The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C. a) A - Transcription, B -Translation, C - Francis Crick b) A - Translation, B - Extension, C - Rosalind Franklin c) A - Transcription, B - Replication, C - James Watson d) A - Translation, B - Transcription, C - Ervin Chargaff 6.) The figure gives an important concept in the genetic implication of DNA. Fill the blanks A, B and C. a) A-Maurice Wilkins, B-Transcription, C-Translation b) A-James Watson, B-Replication, C-Extension c) A-Erwin Chargaff, B-Translation, C-Replication d) A-Francis Crick, B-Translation, C-Transcription 7.) What are the structures called that give an appearance as ‘beads-on-string’ in the chromosomes when viewed under electron microscope? a) Genes b) Nucleotides c) Nucleosomes
d) Base pairs 8.) Which one of the following does not follow the central dogma of molecular biology? a) Pea b) Mucor c) Chlamydomonas d) HIV 9.) The 3′ - 5′ phosphodiester linkages inside a polynucleotide chain serve to join a) one DNA strand with the other DNA strand b) one nucleoside with another nucleoside c) one nucleotide with another nucleotide d) one nitrogenous base with pentose sugar. (Main 2010) 10.) Which one of the following statements about the particular entity is true ? a) Centromere is found in animal cells, which produces aster during cell division. b) The gene for producing insulin is present in every body cell. c) Nucleosome is formed of nucleotides. d) DNA consists of core of eight histones. (Main 2010) 11.) In the DNA molecule, a) the proportion of adenine in relation to thymine varies with the organism b) there are two strands which run antiparallel-one in 5′ → 3′ direction and other in 3′ → 5′ c) the total amount of purine nucleotides and pyrimidine nucleotides is not always equal d) there are two strands which run parallel in the 5′ → 3′ direction. 12.) Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it? a) Guanine, Adenine - Purines b) Adenine, Thymine - Purines c) Thymine, Uracil - Pyrimidines d) Uracil, Cytosine - Pyrimidines 13.) One turn of the helix in a B-form DNA is approximately a) 2 nm b) 20 nm c) 0.34 nm d) 3.4 nm. 14.) Antiparallel strands of a DNA molecule means that a) one strand turns clockwise b) one strand turns anti-clockwise c) the phosphate groups of two DNA strands, at their ends, share the same position d) the phosphate groups at the start of two DNA strands are in opposite position (pole). 15.) Which one of the following makes use of RNA template to synthesise DNA?
a) DNA polymerase b) RNA polymerase c) Reverse transcriptase d) DNA dependant RNA polymerase 16.) Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain? a) Lipase b) Protease c) Endonuclease d) Exonuclease 17.) The following ratio is generally constant for a given species: a) A + G / C + T b) T + C / G + A c) G + C / A + T d) A + C / T + G. 18.) In a DNA percentage of thymine is 20% then what will be percentage of guanine? a) 20% b) 40% c) 30% d) 60% 19.) Length of one loop of B-DNA a) 3.4 nm b) 0.34 nm c) 20 nm d) 10 nm. 20.) DNA is mainly found in a) nucleolus b) nucleus only c) cytoplasm only d) none of these. 21.) In prokaryotes, the genetic material is a) linear DNA without histones b) circular DNA without histones c) linear DNA with histones d) circular DNA with histones. 22.) In DNA, when AGCT occurs, their association is as per which of the following pair? a) AT-GC b) AG-CT c) AC-GT d) All of these 23.) The eukaryotic genome differs from the prokaryotic genome because
a) the DNA is complexed with histone in prokaryotes b) the DNA is circular and single stranded in prokaryotes c) repetitive sequences are present in eukaryotes d) genes in the former case are organised into operons. 24.) Genes are packaged into a bacterial chromosome by a) acidic protein b) actin c) histones d) basic protein. 25.) Radiotracer technique shows that DNA is in a) multi-helix stage b) single-helix stage c) double-helix stage d) none of these. 26.) Nucleosome core is made of a) H , H A, H B and H 0 2 2 3 b) H , H A, H B, H 1 2 2 4 c) H , H A, H B, H and H 1 2 2 3 4 d) H A, H B, H and H 2 2 3 4 . 27.) A DNA with unequal nitrogen bases would most probably be a) single stranded b) double stranded c) triple stranded d) four stranded. 28.) Nucleotide arrangement in DNA can be seen by a) X-ray crystallography b) electron microscope c) ultracentrifuge d) light microscope. 29.) An octamer of 4 histones complexed with DNA forms a) endosome b) nucleosome c) mesosome d) centromere. 6.2 The Search for Genetic Material 30.) The experimental proof for semi-conservative replication of DNA was first shown in a a) fungus b) bacterium c) plant d) virus. 31.) Select the correct match.