DNA Structure and Replication
Which strand replicates the fastest during DNA replication?
leading strand
Which sections of pre-mRNA are spliced before becoming mature mRNA?
introns
What are ribosomes made up of? (be specific)
2 rRNA subunits
What are bacterial genes often found in? (Groups of bacterial genes are called...)
operons
A mutation of a single base pair which does not change the amino acid sequence is called what?
silent mutation
DNA replication has a property where each strand in the double helix will emerge into a new strand of DNA. What is this property called?
semiconservative replication
Where does transcription occur?
nucleus
What is the purpose of a tRNA molecule?
What is the name of a regulatory protein that increases speed of transcription?
activator
Genetic differences in a population are called what?
genetic variation
How many pyrimidine bases exist? Double points if you can identify them all.
3 (Cytosine, Thymine, Uracil)
What is the process in which a single pre-mRNA molecule gives rise to two mRNA molecules?
alternative splicing
What is the start codon?
A-U-G
By default, a certain gene is turned on unless a repressor protein is bound. What type of operon is this?
repressible operon
What technique is able to separate DNA fragments by size?
gel electrophoresis
Which enzyme uncoils DNA to prepare it for replication?
topoisomerase
What sequence in the DNA codes for the stopping of transcription?
termination sequence
How many distinct STOP codon sequences are there?
3
A certain gene is located in both liver and blood cells. In blood cells, certain proteins that degrade the gene are present, however, in liver cells, these proteins are absent. What is the result of the gene expression between both liver and blood cells?
The gene will be expressed in liver cells but not in blood cells.
An individual is diagnosed with a condition called Duchenne muscular dystrophy. This condition is caused by a base pair change on the DMD which causes a premature stop codon, meaning individuals with the disease have a much shorter DMD gene protein than normal. Which type of mutation is caused?
nonsense mutation
What is the difference in shape between prokaryotic chromosomes and eukaryotic chromosomes?
Prokaryotic chromosomes are circular, while eukaryotic chromosomes are linear
What feature on a mature mRNA strand protects the strand from being degraded by exonucleases?
5' cap
If the fifth amino acid in a polypeptide chain is a serine (Ser), what is the first amino acid?
methionine (Met)
A gene coding for a protein called tryptophan is found in the trp operon. In the absence of tryptophan, transcription will occur, leading to the creation of tryptophan. When tryptophan is present, it assists a repressor protein bind to the trp operon to prevent transcription from occurring.
In this case, tryptophan acts as what in the operon?
corepressor
A mutation in the CFTR gene can cause cystic fibrosis, a lifelong condition which increases vulnerability to lung infections. The mutation that causes cystic fibrosis is the deletion of three base pairs.
A scientist wants to treat cystic fibrosis by inserting a normal CFTR gene into an individual with a mutated CFTR gene using a vector. What method should he use?
gene therapy