Why do the genomes of eukaryotes, such as Drosophila, need to have multiple origins of replication, whereas bacterial genomes, such as that of E. coli, have only a single origin?

Explanation:

The genome of euakaryotes in linear and its length is long, thus multiple replication origin ensures replication is carried out very fast in the eukaryotes in a short amount of time. While the genome of bacteria is circular in nature and not as long as that of eukaryotes and needs just one replication origin to carry out replication process within a short period of time

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.