Molecular genetics multiple choice Flashcards
the nucleotide at the end of one strand of a fragment of double stranded dna has a free phosphate attached to the 5’ carbon of its deoxyribose sugar. The complementary nucleotide has
a hydroxyl group (-OH) attached to the 3’ carbon of its deoxyribose sugar
. which of the following statements is false regarding the discovery of the model of DNA
Erwin Chargaff= discovered that in the DNA of numerous organisms the amount of adenine is equal to the amount of thymine , and the amount of guanaine is equal to cytosine
Rosalind franklin= produced an xray diffraction pattern , shape of double helix
James Watson and Francis crick = deduced the structure of DNA using information from the work of char gaff franklin and Maurice Wilkins
during DNA replication one of the new strands of DNA is synthesized continuously while the other is synthesized as a number of separate fragments of dna that are subsequently linked by dna ligase. This is because
DNA polymerase III only synthesizes DNA in the 5’ - 3’ direction
an enzyme which excises a mismatched base in a newly synthesized strand of DNA IS CALLED
an exonuclease
In what order do the following molecules become involved in DNA replication in E. coli?
gyrase, helicase, SSBs, primase, DNA Polymerase III (DNA Polymerase I and ligase)
which of the following correctly describes the order in which cell components become involved in protein synthesis?
RNA polymerase, mRNA, ribosome, tRNA
Line A below shows the peptide synthesized after transcription and translation of a piece of DNA. Line b shows the peptide synthesized after a mutation in this piece of DNA
A base substitution
in eukaryotes , introns are removed before mRNA leaves the nucleus because
They do not code for protein
which is the correct sequence for the enzymes listed In DNA replication?
gyrase, helicase, primase, DNA Polymerase III, DNA Polymerase I, ligase, exonuclease
spliceosomes remove introns form a mRNA. This offers the possibility of control at which of the following levels?
Post transcriptional
the central dogma states that the flow of genetic information is in the direction
DNA, RNA, protein
there are three kinds of RNA polymerase in eukaryotes – rna polymerases 1 2 and 3. Rna polymerase 1 2 3 are used to transcribe
- rRNA, mRNA, tRNA
the function of the cap and poly a tail that is added to mrna in eukaryotic cells is to
prevent degradation of the mRNA
Which of the following statements about DNA annealing is false?
- when hydrogen bonds are formed between purines and pyrimidines
