The structural stability of the double helix of DNA is as cribbed largely to (A) Hydrogen bonding between adjacent purine bases (B) Hydrophobic bonding between staked purine and pyrinuidine nuclei  (C) Hydrogen bonding between adjacent pyrimidine bases (E) Hydrogen bonding between purine and pyrimidine bases

1 Answer

Answer :

Answer :  D

Related questions

Description : In DNA, genetic information is located in (A) Purine bases (B) Pyrimidine bases (C) Purine and pyrimidine bases (D) sugar

Last Answer : Answer : C

Description : Ultraviolet light can damage a DNA strand causing (A) Two adjacent purine residue to form a covalently bounded dimer (B) Two adjacent pyrimidine residues to form covalently bonded dimer (C) Disruption of phosphodiesterase linkage (D) Disruption of non-covalent linkage

Last Answer : Answer : B

Description : The two strands of the DNA double helix are held together by (a) Hydrogen bonds (b)C=C double bonds (c) Hydrophobic bonds (d) Peptide bonds

Last Answer : Ans:(a)

Description : Alkylating agents exert cytotoxic action by inducing: A. Breakage of DNA strand B. Cross linking of DNA strands C. Abnormal pairing of purine and pyrimidine bases D. All of the above

Last Answer : D. All of the above

Description : The available PRPP is used preferentially for (A) De novo synthesis of purine nucleotides (B) De novo synthesis of pyrimidine nucleotides (C) Salvage of purine bases (D) Salvage of pyrimidine bases

Last Answer : Answer : C

Description : Intestinal nucleosidases act on nucleosides and produce (A) Purine base only (B) Phosphate only (C) Sugar only (D) Purine or pyrimidine bases and sugars

Last Answer : Answer : D

Description : α-Helix is formed by (A) Hydrogen bonds (B) Hydrophobic bonds (C) Electrostatic bonds (D) Disulphide bonds

Last Answer : Answer : A

Description : In RNA molecule guanine content does not necessarily equal its cytosine content nor does its adenine content necessarily equal its uracil content since it is a (A) Single strand molecule ( ... stranded molecule (C) Double stranded helical molecule (D) Polymer of purine and pyrimidine ribonucleotides

Last Answer : Answer : A

Description : Which is wrong about nucleic acids? (a) DNA is single stranded in some viruses. (b) RNA is double stranded occasionally. (c) Length of one helix is 45 Å in B-DNA. (d) One turn of Z-DNA has 12 bases

Last Answer : (c) Length of one helix is 45 Å in B-DNA

Description : The double helix is a structural arrangement associated with _____. a. A Polysaccharide. b. The DNA Molecule. c. Glucose Molecules In Starch. d. A Protein.

Last Answer : b. The DNA Molecule.

Description : In many proteins the hydrogen bonding produces a regular coiled arrangement which is called as (A) β-Helix (B) α-Helix (C) Both (A) and (B) (D) Spiral

Last Answer : Answer : B

Description : In many proteins the hydrogen bonding produces a regular coiled arrangement called (A) α-helix (B) β-helix (C) Both (A) and (B) (D) None of these

Last Answer : Answer : A

Description : True statements about the nucleic acid include: a. contains purine and pyrimidine which are bound together by covalent bonds b. there is always an equal concentration of purine and pyrimidine c. in RNA, ... d. introns is more common than exons on the DNA e. the histones mark the excision site

Last Answer : there is always an equal concentration of purine and pyrimidine

Description : n the DNA molecule, (a) the proportion of adenine in relation to thymine varies with the organism (b) there are two strands which run anti- parallel-one in 5′ → 3′ direction and other in 3′ → ... is not always equal (d) there are two strands which run parallel in the 5′ → 3′ direction.

Last Answer : (b) there are two strands which run anti- parallel-one in 5′ → 3′ direction and other in 3′ → 5′

Description : Proteins which interact with DNA and affect the rate of transcription possess the following structural motif: (A) Helix-turn-helix motif (B) Zinc finger motif (C) Leucine zipper motif (D) All of these

Last Answer : Answer : D

Description : The α-Helix is held in a coiled conformation partially because of : (a) Optical activity (b) Hydrogen bonding (c) Resonance (d) Delocalization

Last Answer : Hydrogen bonding

Description : List the pyrimidine bases of DNA. -Biology

Last Answer : answer:

Description : Which two of the following four bases in DNA are pyrimidine (pron: pie-rim-eh-den) bases? a) cytosine b) thymine c) adenine d) guanine (pron: gwa - neen)

Last Answer : ANSWER: A and B -- CYTOSINE and THYMINE

Description : Which one of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbanoyl phosphate (C) Carbondioxide (D) Tetrahydrofolate

Last Answer : Answer : A

Description : Which one of the following causes frame shift mutation? (A) Transition (B) Transversion (C) Deletion (D) Substitution of purine to pyrimidine

Last Answer : Answer : C

Description : 5-Phosphoribosyl-1-pyrophosphate is required for the synthesis of (A) Purine nucleotides (B) Pyrimidine nucleotides (C) Both (A) and (B) (D) None of these

Last Answer : Answer : C

Description : Genetic code is (A) Collection of codon (B) Collection of amino acids (C) Collection of purine nucleotide (D) Collection of pyrimidine nucleotide

Last Answer : Answer : A

Description : Gout is a metabolic disorder of catabolism of (A) Pyrimidine (B) Purine (C) Alanine (D) Phenylalanine

Last Answer : Answer : B

Description : Pyrimidine and purine nucleoside biosynthesis share a common precursor: (A) PRPP (B) Glycine (C) Fumarate (D) Alanine

Last Answer : Answer : A

Description : A nucleotide consists of (A) A nitrogenous base like choline (B) Purine + pyrimidine base + sugar + phosphorous (C) Purine or pyrimidine base + sugar (D) Purine or pyrimidine base + phosphorous

Last Answer : Answer : B

Description : A nucleoside consists of (A) Nitrogenous base (B) Purine or pyrimidine base + sugar (C) Purine or pyrimidine base + phosphorous (D) Purine + pyrimidine base + sugar + phosphorous

Last Answer : Answer : B

Description : Which one of the following causes frame shift mutation? (A) Transition (B) Transversion (C) Deletion (D) Substitution of purine to pyrimidine

Last Answer : Answer : C

Description : All mammalian steroid hormones are formed from (A) Purine (B) Pyrimidine (C) Cholesterol (D) Pyrrole

Last Answer : Answer : C

Description : Thiamine is (A) Water-soluble vitamin (B) Fat soluble vitamin (C) Purine base (D) Pyrimidine base

Last Answer : Answer : D

Description : Thymine is (A) Water soluble vitamin (B) Fat soluble vitamin (C) Purine base (D) Pyrimidine base

Last Answer : Answer : D

Description : Vitamin B12 has a complex ring structure (corrin ring) consisting of four (A) Purine rings (B) Pyrimidine rings (C) Pyrrole rings (D) Pteridine rings

Last Answer : Answer : C

Description : Which of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbamoyl phosphate (C) CO2 (D) Glutamine

Last Answer : Answer : A

Description : The double helical structure of DNA is held together by (a) sulfur-sulfur linkages (b) peptide bonding (c) hydrogen bonding (d) glycosidic bonds

Last Answer : hydrogen bonding

Description : List the purine bases of DNA. -Biology

Last Answer : answer:

Description : Which two of the following four bases in DNA are purine bases? a) adenine b) thymine c) cytosine d) guanine

Last Answer : ANSWER: A and D -- ADENINE and GUANINE

Description : DNA topoisomerase I of E. coli catalyses (A) Relaxation of negatively supercoiled DNA (B) Relaxation of positively supercoiled DNA (C) Conversion of negatively supercoiled DNA into positively supercoiled DNA (D) Conversion of double helix into supercoiled DNA

Last Answer : Answer : A

Description : Melting temperature of DNA is the temperature at which (A) Solid DNA becomes liquid (B) Liquid DNA evaporates (C) DNA changes from double helix into supercoiled DNA (D) Native double helical DNA is denatured

Last Answer : Answer : D

Description : Left handed double helix is present in (A) Z-DNA (B) A-DNA (C) B-DNA (D) None of these

Last Answer : Answer : A

Description : The enzyme DNA ligase (A) Introduces superhelical twists (B) Connects the end of two DNA chains (C) Unwinds the double helix (D) Synthesises RNA primers

Last Answer : Answer : B

Description : The width (helical diameter) of the double helix in B-form DNA in nm is (A) 1 (B) 2 (C) 3 (D) 4

Last Answer : Answer : B

Description : Mitochondrial DNA is (A) Circular double stranded (B) Circular single stranded (C) Linear double helix (D) None of these

Last Answer : A

Description : The following coenzyme is required for catabolism of pyrimidine bases: (A) NADH (B) NADPH (C) FADH2 (D) None of these

Last Answer : Answer : B

Description : Salvage of purine bases is regulated by (A) Adenosine phosphoribosyl transferase (B) Hypoxanthine guanine phosphoribosyl transferase (C) Availability of PRPP (D) None of these

Last Answer : Answer : C

Description : The enzyme required for salvage of free purine bases is (A) Adenine phosphoribosyl transferase (B) Hypoxanthine guanine phosphoribosyl transferase (C) Both (A) and (B) (D) None of these

Last Answer : Answer : C

Description : Free purine bases which can be salvaged are (A) Adenine and guanine (B) Adenine and hypoxanthine (C) Guanine and hypoxanthine (D) Adenine, guanine and hypoxanthine

Last Answer : Answer : D

Description : Difference between purine and pyrimidine. -Biology

Last Answer : answer:

Description : Assertion: Uric acid is produced by the metabolism of purine and pyrimidine. Reason: Uric acid has high toxicity and is soluble in water.

Last Answer : Assertion: Uric acid is produced by the metabolism of purine and pyrimidine. Reason: Uric acid has ... D. If both Assertion and Reason are false

Description : A nucleotide is formed of (a) purine, pyrimidine and phosphate (b) purine, sugar and phosphate (c) nitrogen base, sugar and phosphate (d) pyrimidine, sugar and phosphate

Last Answer : (c) nitrogen base, sugar and phosphate

Description : Adenine is (a) purine (b) pyrimidine (c) nucleoside (d) nucleotide.

Last Answer : (a) purine

Description : Uridine, present only in RNA is a (a) nucleoside (b) nucleotide (c) purine (d) pyrimidine.

Last Answer : a) nucleoside