Biology 116 Final Exam Questions with
Complete Answers
Types of DNA polymerase - ANSWER-DNA polymerase 1 and 3 complete DNA
replication
DNA polymerase 2 repairs DNA
Helicase - ANSWER-Breaks H bonds between DNA strands
SSBPs (single strand DNA binding proteins) - ANSWER-stabalizes single strands of
DNA after bonds are broken
Keeps the strands seperate
Topoisomerase - ANSWER-cuts and rejoins DNA downstream to relieve tension
force
Primase - ANSWER-Synthesizes RNA primer
creates a short stretch of ribonucleotides that are complimentary to the origin of
repication
How is the leading strand synthesized - ANSWER-the leading strand is synthesized
continuously in the 5' to 3' direction
RNA primer - ANSWER-provides 3'OH group for DNA pol to synthesize DNA
Lagging strand synthesis - ANSWER-synthesized discontinuously in the direction
away from the replication fork
synthesized in short discontinuous strands called Ozaki fragments
After second O frag is synthesized DNA polymerase I removes RNA primer and
replaces it with DNucleotides
DNA ligase closes gap in sugar phosphate backbone
Replisome - ANSWER-most of the enzymes in DNA synthesis are present in one
large multienzyme machine
The two DNA polymerase appear to move in the Same direction
Repairing mistakes - ANSWER-DNA polymerase inserts the wrong nucletide
1/100000 nucleotides but it proofreads and stops and replaces the mismatched
nucleotide reducing errors to 1 in 10 million
Mismatch repair enzyme systems - ANSWER-recognize mismatched pairs and
remove and replace the incorrect section
, Nucleotide excision repair - ANSWER-recognizes DNA damage done by radiation or
chemicals
ie thymidine dimers
Xeroderma pigmentosum - ANSWER-rare autosomal disease caused by mutation in
nucleotide excision repair systems
causes skin lesions
One gene, one enzyme hypothesis - ANSWER-a gene contains the information
needed to make an enzyme.
The central dogma of molecular biology - ANSWER-Francis, Crick different
combinations of the 4 nucleotide bases could specify the 20 amino acids
Jacob and Monod proposed RNA as an intermediary between DNA and protein
Summarizes flow of genetic info
Three main types of RNA - ANSWER-Messenger RNA, Transfer RNA, Ribosomal
RNA
Messenger RNA - ANSWER-carries information from DNA to the site of protein
synthesis
RNA structure - ANSWER-has a linear primary structure of ribonucleotides linked by
phosphodiester bonds
has a sugar phosphate backbone
uses nitrogenous bases uracil instead of thymine
RNA secondary structure - ANSWER-Secondary structure of RNA occurs via
complementary base pairing between stretches of nucleotides
This forms Hairpin Structure
RNA can also form tertiary and quaterary structures
Genotype - ANSWER-combination of alleles for a gene
Phenotype - ANSWER-Physical traits that are the products of proteins
Proteins made by a particular gene detirmines the phenotype
Allele - ANSWER-sequence of bases in DNA
Proteins produced by different alleles of the same gene differ in amino acid
sequence
Exceptions to the central dogma - ANSWER-some genes code for RNA molecules
such as rRNA and tRNA
genetic info can be transferred from RNA back to DNA (reverse transcriptase
enzyme)
Number of possible genetic codes - ANSWER-number of codons to the power of
number of bases inside the code
Start codon - ANSWER-AUG
Complete Answers
Types of DNA polymerase - ANSWER-DNA polymerase 1 and 3 complete DNA
replication
DNA polymerase 2 repairs DNA
Helicase - ANSWER-Breaks H bonds between DNA strands
SSBPs (single strand DNA binding proteins) - ANSWER-stabalizes single strands of
DNA after bonds are broken
Keeps the strands seperate
Topoisomerase - ANSWER-cuts and rejoins DNA downstream to relieve tension
force
Primase - ANSWER-Synthesizes RNA primer
creates a short stretch of ribonucleotides that are complimentary to the origin of
repication
How is the leading strand synthesized - ANSWER-the leading strand is synthesized
continuously in the 5' to 3' direction
RNA primer - ANSWER-provides 3'OH group for DNA pol to synthesize DNA
Lagging strand synthesis - ANSWER-synthesized discontinuously in the direction
away from the replication fork
synthesized in short discontinuous strands called Ozaki fragments
After second O frag is synthesized DNA polymerase I removes RNA primer and
replaces it with DNucleotides
DNA ligase closes gap in sugar phosphate backbone
Replisome - ANSWER-most of the enzymes in DNA synthesis are present in one
large multienzyme machine
The two DNA polymerase appear to move in the Same direction
Repairing mistakes - ANSWER-DNA polymerase inserts the wrong nucletide
1/100000 nucleotides but it proofreads and stops and replaces the mismatched
nucleotide reducing errors to 1 in 10 million
Mismatch repair enzyme systems - ANSWER-recognize mismatched pairs and
remove and replace the incorrect section
, Nucleotide excision repair - ANSWER-recognizes DNA damage done by radiation or
chemicals
ie thymidine dimers
Xeroderma pigmentosum - ANSWER-rare autosomal disease caused by mutation in
nucleotide excision repair systems
causes skin lesions
One gene, one enzyme hypothesis - ANSWER-a gene contains the information
needed to make an enzyme.
The central dogma of molecular biology - ANSWER-Francis, Crick different
combinations of the 4 nucleotide bases could specify the 20 amino acids
Jacob and Monod proposed RNA as an intermediary between DNA and protein
Summarizes flow of genetic info
Three main types of RNA - ANSWER-Messenger RNA, Transfer RNA, Ribosomal
RNA
Messenger RNA - ANSWER-carries information from DNA to the site of protein
synthesis
RNA structure - ANSWER-has a linear primary structure of ribonucleotides linked by
phosphodiester bonds
has a sugar phosphate backbone
uses nitrogenous bases uracil instead of thymine
RNA secondary structure - ANSWER-Secondary structure of RNA occurs via
complementary base pairing between stretches of nucleotides
This forms Hairpin Structure
RNA can also form tertiary and quaterary structures
Genotype - ANSWER-combination of alleles for a gene
Phenotype - ANSWER-Physical traits that are the products of proteins
Proteins made by a particular gene detirmines the phenotype
Allele - ANSWER-sequence of bases in DNA
Proteins produced by different alleles of the same gene differ in amino acid
sequence
Exceptions to the central dogma - ANSWER-some genes code for RNA molecules
such as rRNA and tRNA
genetic info can be transferred from RNA back to DNA (reverse transcriptase
enzyme)
Number of possible genetic codes - ANSWER-number of codons to the power of
number of bases inside the code
Start codon - ANSWER-AUG
