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Self Assessment Question 1. Which chemical group is at the 5' end of a single polynucleotide strand? Hydroxyl group Diester group Purine base Phosphate group Nitrogen group. Self Assessment Question 1 Answer.
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Self Assessment Question 1 • Which chemical group is at the 5' end of a single polynucleotide strand? • Hydroxyl group • Diester group • Purine base • Phosphate group • Nitrogen group
Self Assessment Question 1 Answer • Which chemical group is at the 5' end of a single polynucleotide strand? • Hydroxyl group • Diester group • Purine base • Phosphate groupCORRECT ANSWER • Nitrogen group
Structure of Nucleic Acid • DNA and RNA consist of only four nucleotides • Adenine (A) and guanine (G) are purines • Cytosine (C), thymine (T) and uracil (U) are pyrimidines • A nucleotides consist of an organic base linked to a five-carbon sugar with a phosphate group attached to carbon 5. • In RNA, the sugar is ribose; in DNA, deoxyribose. • Polynucleotide sequences are read in 5’ -> 3’ direction
Self Assessment Question 2 • Which chemical group is at the 3' end of a single polynucleotide strand? • Phosphate group • Hydroxyl group • Purine base • Nitrogen group • Methyl group
Self Assessment Question 2 Answer • Which chemical group is at the 3' end of a single polynucleotide strand? • Phosphate group • Hydroxyl groupCORRECT ANSWER • Purine base • Nitrogen group • Methyl group
Structure of Nucleic Acid • DNA and RNA consist of only four nucleotides • Adenine (A) and guanine (G) are purines • Cytosine (C), thymine (T) and uracil (U) are pyrimidines • A nucleotides consist of an organic base linked to a five-carbon sugar with a phosphate group attached to carbon 5. • In RNA, the sugar is ribose; in DNA, deoxyribose. • Polynucleotide sequences are read in 5’ -> 3’ direction
Self Assessment Question 3 • The purine bases are: • Thymine and cytosine • Thymine and guanine • Cytosine and Adenine • Cytosine and guanine • Adenine and guanine
Self Assessment Question 3 Answer • The purine bases are: • Thymine and cytosine • Thymine and guanine • Cytosine and Adenine • Cytosine and guanine • Adenine and guanineCORRECT ANSWER
Self Assessment Question 4 • The pyrimidine bases are: • Thymine and cytosine • Thymine and guanine • Adenine and guanine • Cytosine and adenine • Cytosine and guanine
Self Assessment Question 4 Answer • The pyrimidine bases are: • Thymine and cytosineCORRECT ANSWER • Thymine and guanine • Adenine and guanine • Cytosine and adenine • Cytosine and guanine
Self Assessment Question 5 • Each new DNA strand is initiated by a: • Short RNA primer • Single-stranded DNA-binding protein • Precursor fragment • Restriction fragment • Specific DNA primer
Self Assessment Question 5 Answer • Each new DNA strand is initiated by a: • Short RNA primerCORRECT ANSWER • Single-stranded DNA-binding protein • Precursor fragment • Restriction fragment • Specific DNA primer
Self Assessment Question 6 • The phenomenon where the two complementary strands of duplex DNA have their 5’-to-3’ directions running in opposite directions is called: • Antiparallel • Nucleic acid hybridization • Renaturation • Rolling-circle replication • Restriction fragment polymorphism
Self Assessment Question 6 Answer • The phenomenon where the two complementary strands of duplex DNA have their 5’-to-3’ directions running in opposite directions is called: • AntiparallelCORRECT ANSWER • Nucleic acid hybridization • Renaturation • Rolling-circle replication • Restriction fragment polymorphism
DNA forms a Double Helix • The bases are projected inward whereas the sugar phosphate backbone is on the outside • The two strands are antiparallel • A is paired with T through two hydrogen bonds • G is paired with C through three hydrogen bonds
Self Assessment Question 7 • The Meselson-Stahl experiment showed that a single round of DNA replication produces: • One DNA molecule made of two parental strands and a second DNA molecule made of two daughter strands. • Two duplex DNA molecules where all of the strands are partly parental and part new DNA. • Two duplex DNA molecules each with one parental strand and one daughter strand. • Many duplex DNA molecules, all with two new daughter strands.
Self Assessment Question 7 Answer • The Meselson-Stahl experiment showed that a single round of DNA replication produces: • One DNA molecule made of two parental strands and a second DNA molecule made of two daughter strands. • Two duplex DNA molecules where all of the strands are partly parental and part new DNA. • Two duplex DNA molecules each with one parental strand and one daughter strand.CORRECT ANSWER • Many duplex DNA molecules, all with two new daughter strands.
DNA Replication: Meselson-Stahl Experiment Results ** • Important points: • The conservative mechanism never generates H-L DNA. • The semiconservative mechanism never generates H-H DNA, but does generate H-L DNA during the second and subsequent doublings. • DNA replicates by which mechanism?
Self Assessment Question 8 • DNA fragments migrate in an electric field because DNA molecules: • Are positively charged • Are neutral in charge • Are negatively charged • Are double stranded • Contain numerous covalent bonds
Self Assessment Question 8 Answer • DNA fragments migrate in an electric field because DNA molecules: • Are positively charged • Are neutral in charge • Are negatively chargedCORRECT ANSWER • Are double stranded • Contain numerous covalent bonds
Self Assessment Question 9 • Endonucleases: • Break internal phosphodiester bonds in a single- or double-stranded nucleic acid molecule. • Remove amino acids from the carboxyl end of a polypeptide chain. • Connect two DNA fragments. • Remove terminal nucleotides from the 3'-end of a polynucleotide chain. • Connect two oligopeptides.
Self Assessment Question 9 Answer • Endonucleases: • Break internal phosphodiester bonds in a single- or double-stranded nucleic acid molecule.CORRECT ANSWER • Remove amino acids from the carboxyl end of a polypeptide chain. • Connect two DNA fragments. • Remove terminal nucleotides from the 3'-end of a polynucleotide chain. • Connect two oligopeptides *Note: restriction enzymes are endonucleases produced by bacteria
Self Assessment Question 10 • A palindrome is a sequence that: • reads differently when read from either direction • can be found in multiple origins of replication • is the same when read from either direction • is used as a primer in DNA replication • contains only purines
Self Assessment Question 10 Answer • A palindrome is a sequence that: • reads differently when read from either direction • can be found in multiple origins of replication • is the same when read from either directionCORRECT ANSWER • is used as a primer in DNA replication • contains only purines websters-dictionary-online.com
Self Assessment Question 11 • Which of the following sequences are palindromes? • 5'-CCAG-3' • 5'-CCCC-3' • 5'-CCAGG-3' • 5'-ACCGGA-3' • 5'-CCATGG-3'
Self Assessment Question 11 Answer • Which of the following sequences are palindromes? • 5'-CCAG-3' • 5'-CCCC-3' • 5'-CCAGG-3' • 5'-ACCGGA-3' • 5'-CCATGG-3'CORRECT ANSWER
Self Assessment Question 12 • Which of the following is a characteristic of restriction enzymes? • Most restriction enzymes recognize a single site. • The restriction site is recognized regardless of the source of the DNA. • The number of times a piece of DNA is cut is determined by the number of times the restriction site is present in the DNA. • Most restriction sites are palindromes. • A, B, C, and D • A and C • B and D
Self Assessment Question 12 Answer • Which of the following is a characteristic of restriction enzymes? • *Most restriction enzymes recognize a single site. • * The restriction site is recognized regardless of the source of the DNA. • * The number of times a piece of DNA is cut is determined by the number of times the restriction site is present in the DNA. • * Most restriction sites are palindromes. • A, B, C, and DCORRECT ANSWER • A and C • B and D