Context: A species can be listed in two ways. The United States Fish and Wildlife Service (FWS) or NOAA Fisheries (also called the National Marine Fisheries Service) can directly list a species through its candidate assessment program, or an individual or organizational petition may request that the FWS or NMFS list a species. A "species" under the act can be a true taxonomic species, a subspecies, or in the case of vertebrates, a "distinct population segment." The procedures are the same for both types except with the person/organization petition, there is a 90-day screening period.

Question: How many different ways can a species be added to the endangered list?
Answer: two ways

Question: What federal program is used to list a species?
Answer: candidate assessment program

Question: How long is the screening period of an individual's or organization's petition to add a species to the list
Answer: 90-day screening period

Question: In the case of vertebrates, what is the most lenient interpretation of "species"?
Answer: a "distinct population segment."

Question: How many ways FWS list a species?
Answer: Unanswerable

Question: Who does the FWS or NMFS have to petition to list a species?
Answer: Unanswerable

Question: How long does an individual have to petition the FWS?
Answer: Unanswerable

Question: In what case does a distinct population segment not count?
Answer: Unanswerable

Question: What is another name for the United States Fish and Wildlife Service (FWS)?
Answer: Unanswerable