The top 20 highest-paid biopharma CEOs 1. Len Schleifer, Regeneron $41.97 million. Schleifer may have popped up on our CEO pay list just a few years ago--and stayed at or near the top--but he's been plugging away at Regeneron since he founded the company in 1988.
Most bacterial species contain a single type of chromosome, but it may be present in multiple copies. Several thousand different genes are interspersed throughout the chromosome; structural gene sequences (encoding proteins) account for the majority of bacterial DNA; nontranscribed DNA sequences between adjacent genes are termed intergenic regions.
Many bacteria (and some yeasts or other fungi) also possess looped bits of DNA known as plasmids, which exist and replicate independently of the chromosome. Plasmids have relatively few genes (fewer than 30). The genetic information of the plasmid is usually not essential to survival of the host bacteria.