©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Genetics PCB 3063 Exam 3 Study Guide
Solutions
Nucleotide - ANSWER✔✔-Repeating structural unit of DNA and RNA. Composed of a nitrogenous base, a
sugar, and a phosphate.
Purines - ANSWER✔✔-Two fused heterocyclic rings
A, G
Pyrimidines - ANSWER✔✔-One single heterocyclic ring
T, U, C
Nucleotide Sugars - ANSWER✔✔-Ribose
Deoxyribose (Base is always attached to C-1' of the sugar.
Phosphates - ANSWER✔✔-Can be attached to the C-5' of the sugar.
Deoxyribonucleo-side - ANSWER✔✔-Base + Sugar
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, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Deoxyribonucleo-tide - ANSWER✔✔-Base + Sugar + Phosphate
Adjacent nucleotides are linked by... - ANSWER✔✔-5'-3' Phosphodiester Bonds
A nucleotide has what on each end? - ANSWER✔✔-A free 5' phosphate
A free 3' hydroxyl
Erwin Chargaff - ANSWER✔✔-A=T
C=G
Rosalind Franklin and Maurice Wilkins - ANSWER✔✔-DNA is a multiple-stranded fiber of 20 A thickness.
Groups spaced 3.4 A along the fiber and a repeating unit every 34 A.
DNA is a helical structure that is not a single strand and consists of about 10 base pairs per complete
turn.
Watson and Crick - ANSWER✔✔-Solved DNA structure
The Double-Helix - ANSWER✔✔-Two anti-parallel strands.
Sugar-phosphate backbone on the outside.
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, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Nitrogenous bases "stacked" on the inside.
The double-helix has how many bp per complete twist? - ANSWER✔✔-10
Which direction does the double-helix turn? - ANSWER✔✔-Right-handed / Clockwise
The two strands of the double-helix are held together by... - ANSWER✔✔-Hydrogen bonds between
complementary bases.
A=T two hydrogen bonds
C=G three hydrogen bonds
B-DNA - ANSWER✔✔-10bp/turn
Biologically favored.
Parallel bases.
A-DNA - ANSWER✔✔-11bp/turn; 23 A diameter
Prevalent under high salt concentrations/low water conditions.
Doubtful to occur under biological conditions.
Page 3/18
FIRST PUBLISH OCTOBER 2024
Genetics PCB 3063 Exam 3 Study Guide
Solutions
Nucleotide - ANSWER✔✔-Repeating structural unit of DNA and RNA. Composed of a nitrogenous base, a
sugar, and a phosphate.
Purines - ANSWER✔✔-Two fused heterocyclic rings
A, G
Pyrimidines - ANSWER✔✔-One single heterocyclic ring
T, U, C
Nucleotide Sugars - ANSWER✔✔-Ribose
Deoxyribose (Base is always attached to C-1' of the sugar.
Phosphates - ANSWER✔✔-Can be attached to the C-5' of the sugar.
Deoxyribonucleo-side - ANSWER✔✔-Base + Sugar
Page 1/18
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Deoxyribonucleo-tide - ANSWER✔✔-Base + Sugar + Phosphate
Adjacent nucleotides are linked by... - ANSWER✔✔-5'-3' Phosphodiester Bonds
A nucleotide has what on each end? - ANSWER✔✔-A free 5' phosphate
A free 3' hydroxyl
Erwin Chargaff - ANSWER✔✔-A=T
C=G
Rosalind Franklin and Maurice Wilkins - ANSWER✔✔-DNA is a multiple-stranded fiber of 20 A thickness.
Groups spaced 3.4 A along the fiber and a repeating unit every 34 A.
DNA is a helical structure that is not a single strand and consists of about 10 base pairs per complete
turn.
Watson and Crick - ANSWER✔✔-Solved DNA structure
The Double-Helix - ANSWER✔✔-Two anti-parallel strands.
Sugar-phosphate backbone on the outside.
Page 2/18
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Nitrogenous bases "stacked" on the inside.
The double-helix has how many bp per complete twist? - ANSWER✔✔-10
Which direction does the double-helix turn? - ANSWER✔✔-Right-handed / Clockwise
The two strands of the double-helix are held together by... - ANSWER✔✔-Hydrogen bonds between
complementary bases.
A=T two hydrogen bonds
C=G three hydrogen bonds
B-DNA - ANSWER✔✔-10bp/turn
Biologically favored.
Parallel bases.
A-DNA - ANSWER✔✔-11bp/turn; 23 A diameter
Prevalent under high salt concentrations/low water conditions.
Doubtful to occur under biological conditions.
Page 3/18
