Final Exam Flashcards
In his transformation experiment, what did Griffith observe?
Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following?
sequence of bases
Once the pattern found after one round of replication was observed, Meselson and Stahl could be confident of which of the following conclusions?
Replication is not conservative.
The leading and the lagging strands differ in that
the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.
which of the enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3’ end of Okazaki fragments?
DNA polymerase I
You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent
leading strands and Okazaki fragments.
involves combining DNA from different sources into a single molecule, such as inserting a gene from one species into a plasmid from another
recombinant DNA technology
cDNA is synthesized from what molecule using an enzyme known as what?
mRNA…reverse transcriptase
a viral enzyme that can synthesize DNA from an RNA template
reverse transcriptase
Garrod, “inborn errors of metabolism”
genes dictate the production of specific enzymes, and affected individuals have a genetic defects that causes them to lack certain enzymes
can allow the production of proteins of different sizes and functions from a single mRNA.
Alternative RNA splicing
RNA polymerase moves in which direction along the DNA?
3’ to 5’ along the template strand
Why might a point mutation in DNA make a difference in the level of a protein’s activity?
It might substitute a different amino acid in the active site.
introduces a premature stop codon into the mRNA.
nonsense mutation
Steroid hormones produce their effects in cells by
binding to intracellular receptors and promoting transcription of specific genes.
