BIOL 253L - Exam 2 UPDATED ACTUAL Exam Questions and CORRECT Answers

BIOL 253L - Exam 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
DNA (deoxyribonucleic acid) - CORRECT ANSWER - - double stranded helix; right
handed
- a polymer of nucleotides
- more stable than RNA because the strands are harder to separate because they are more
attracted to each other than the surrounding water
- each nucleotide consists of:
1. Sugar (deoxyribose)
2. Phosphate
3. One of Four Nitrogenous Bases:
- Adenine (A)
- Guanine (G)
- Thymine (T)
- Cytosine (C)


RNA - CORRECT ANSWER - - a polymer of nucleotides
- more polar and therefore less hydrophobic than DNA because of the increased polarity of the
extra hydroxyl group in ribose
- each nucleotide consists of:
1. Sugar (ribose)
2. Phosphate
3. One of Four Nitrogenous Bases:
- Adenine (A)
- Guanine (G)
- Uracil (U)
- Cytosine (C)

, Nucleotide - CORRECT ANSWER - - Base
- Phosphate
- Sugar


Nitrogenous Base - CORRECT ANSWER - - Adenine
- Thymine
- Guanine
- Cytosine
- Uracil


Ribose - CORRECT ANSWER - "normal" sugar, with one oxygen atom attached to each
carbon atom


Deoxyribose - CORRECT ANSWER - modified sugar, lacking one oxygen atom



5' --> 3' - CORRECT ANSWER - The sequence of the strand is read from...



Plasmid - CORRECT ANSWER - - relatively small, circular double-stranded DNA molec
that are replicated independently of the chromos
- naturally found in many bacterial cells, but may be found in eukaryotic cells
- do not encode func essential to cellular growth under optimum conditions
- smaller than chromos in size
- low copy (less than 30)
- high copy (hundreds)


Vector - CORRECT ANSWER - - aka plasmids
- three features common to plasmid vectors used in lab:
1. origin of replication