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Exam 1
Molecular Biology
| Question | Answer |
|---|---|
| What end do nucleotides add to? | 3' |
| Adenine pairs with.... | thymine |
| Guanine pairs with... | cytosine |
| Are C-G bonds more stable or are A-T bonds more stable? | C-G because of 3 hydrogen bonds |
| A nucleotide has | nucleic acid base, sugar and a phosphate |
| The phosphodiester bond between neighboring nucleotides in DNA is | 3' to 5' |
| What are the 4 types of nitrogenous bases | adenine, guanine, thymine, cytosine |
| purines | adenine and guanine |
| pyrimidines | cytosine and thymine |
| In RNA U (uracil) replaces.... | thymine |
| More G-C bonds means | higher melting point |
| C-value and C-value paradox | genome size; genome size is not related to complexity of an organism |
| Decrease in salt concentration will....... Tm of DNA | Decrease |
| DNA can be denatured by: | low salt concentration, heat, organic solvents, High pH |
| The most abundant RNA in a cell is: | rRNA (protein translation) |
| DNA insertion in a vector shuts down the LacZ gene expression, and turns the c colony to white | Blue-white screening |
| Blue colonies | no insert |
| white colonies | contains insert |
| Chain terminating nucleotides | ddNTPs |
| What are the differences btwn sanger sequencing and PCR | ddNTPs in sanger and theres 2 primers for PCR and only 1 for DNA sequencing |
| Shows where your cloning gene is expressed | Reporter gene |
| The enzyme that cuts at a specific site is | restriction enzyme |
| DNA fingerprinting is | used to identify persons base on their unique DNA |
| Southern blot is to detect specific | DNA |
| The enzyme use in PCR is | DNA ligase |
| Which cycle starts to make two of exact length specified by the pair of primers in PCR | 3 |
| cDNA is: | eukaryotic DNA with only exons that can be cloned into prokaryotes |
| Scientists use PUC18 as a gene cloning vector that includes a gene for a portion of beta-galactosidase | if foreign DNA is inserted, the beta galactosidase marker is inactivated, and the colonies remain white |
| To carry out sanger sequencing a mixture is needed containing | SSDNA, DNA polymerase, four deoxyribonucleotides a,t,c,g |
| What is the function of dideoxynucleotides in sanger DNA sequencing | they stop synthesis at a specific site, so the base at that site can be determined |
| a method for determining the DNA sequence of an entire genome. After a genome is cut into small fragments, each fragment is sequenced and then placed in the proper order | whole genome shotgun method |
| ddNTPs are used in which biochemical reactions | DNA sequencing |
| What is BLAST | BLAST searches for sequence matches in a nucleotide or protein database |
| You have a DNA sequence and you wish to find out whether it could encode a protein. Which BLAST program should you use? | BLASTP |
| Which of the following reporter genes cannot be used for live cell imaging? | beta-galactosidase |
| Genome-wide gene expression patterns can be studied using | microarrays |
| To use a microarray, mRNA from cells of interest are first converted to | cDNA |
| When DNA is damaged by UV light and is not repaired | neither DNA replication nor transcription can occur and the organism will probably die |
| Which of the following mechanisms is required to repair pyrimidine dimers cause by ultra violet in the presence of light in bacteria | photoreactivation |
| In methyl-directed mismatch repair, the strand that is repaired is | the non-methylated strand |
| In humans, xeroderma pigmentosum is cause by mutations in | nucleotide excision repair |
| DNA replication is | semiconservative |
| DNA polymerase I is.... | most abundant |
| DNA polymerase II is... | major enzyme for DNA replication |
| Arrange the following proteins in the proper order they participate in DNA replication | helicase, SS binding protein, primase, DNA polymerase I |
| How many replication forks would be present in the E. Coli chromosome for cells that are growing under optimal condition | two |
| DNA polymerase use their....... activity to remove a mismatched basepair | 3' to 5' |
| Proofreading by DNA polymerase involves the removal of | several bases on the newly synthesized strand of DNA |
| DNA polymerase cannot replicate | the 3' end of linear chromosomes |
| Which of the following best describes the function of telomerase at the telomere? | it adds new DNA to the longer strand of the DNA overhang |