The term "endangered species" means any species which is in danger of extinction throughout all or a significant portion of its range.

The question states: "The term 'endangered species' means any species which is in danger of extinction throughout all or a significant portion of its range." This definition is attributed to the Endangered Species Act of 1973, Section 3-(6).

According to the Endangered Species Act of 1973, Section 3(6) (16 U.S.C. § 1532(6)), the term "endangered species" is defined as "any species which is in danger of extinction throughout all or a significant portion of its range other than a species of the Class Insecta determined by the Secretary to be a pest whose protection under the provisions of this chapter would present an overwhelming and overriding risk to man."

The statement in the question accurately captures the primary part of the definition of "endangered species" as per the Act. While the full legal text includes an exclusion for certain insect pests, the core definition provided in the question is correct and forms the basis for identifying an endangered species. Therefore, the statement is considered true in the context of a general definition.

The final answer is $\text{a. True}$