Explain why DNA fragments migrate toward the positive electrode and why some fragments migrate more rapidly than others during gel electrophoresis
How does this electronegativity influence observations and conclusions drawn from DNA migrated through an agarose gel?
What will be an ideal response?
Answer: DNA is negatively charged due to its phosphate backbone, and because opposite charges are attracted to each other DNA migrates towards the positive electrode. A large DNA size (or length) runs slower on a gel despite having a stronger charge than a smaller fragment, because the agarose (or polyacrylamide) within the gel acts as a physical barrier to impede and slow down the larger DNA molecules.
You might also like to view...
Which of the following is nottrue of the regulation of the trp operon?
A. Transcription attenuation relies on the fact that bacteria lack a nucleus. B. The level of tryptophan in the cell regulates the rate of transcription after transcription begins. C. The level of tryptophan in the cell regulates the rate of transcription before transcription begins. D. RNA polymerase is recruited to the promoter when tryptophan levels are high.
Which of the following does NOT occur in
prophase I of meiosis? a. cytokinesis b. pairing of homologues c. formation of a bipolar spindle d. crossing over e. condensation of chromosomes
Refer to the accompanying figure. Which statement about label 1 is FALSE?
a. It is haploid. b. It was produced by mitosis. c. It was produced from a megaspore. d. It is not a product of fertilization. e. It is part of the sporophyte generation.
Sperm production is called ____.
A. parthenogenesis B. spermatocytosis C. oocytosis D. oogenesis E. spermatogenesis