#Question id: 2875
#Unit 2. Cellular Organization
Which of the following statements is/are CORRECT from the following?
I. The chromosome of the small monkey DNA virus SV40 is a circular, double-helical DNA molecule of 5000 bp.
II. The phage Lambda genome is a linear single-stranded molecule in the virion particle.
III. Circular DNA molecules purified from both bacteria and eukaryotes are usually negatively supercoiled, having values of sigma of approximately –0.06.
IV. Prokaryotes have a special type I topoisomerase known as “DNA gyrase” that introduces, rather than removes, negative supercoils.
V. DNA disentanglement, generally catalyzed by a type II topoisomerase, is also required for a successful round of DNA replication and cell division in eukaryotes.
#Question id: 3972
#Unit 3. Fundamental Processes
An enhancer
#Question id: 8714
#Unit 9. Diversity of Life Forms
The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that ________.
#Question id: 23227
#Unit 2. Cellular Organization
#Question id: 53
#Unit 1. Molecules and their Interaction Relevant to Biology
Calculate the number of times the DNA of a modern E. coli cell has been copied accurately since its earliest bacterial precursor cell arose about 3.5 billion years ago. Assume for simplicity that over this time period, E. coli has undergone, on average, one cell division every 12 hours (this is an overestimate for modern bacteria, but probably an underestimate for ancient bacteria).