Update Dropdown

A configurable list of predefined values used for standardizing data entry in schema fields. Dropdowns provide controlled vocabulary choices that ensure consistency when users fill out entity and object fields. Each Dropdown belongs to a Registry (see registry) and contains one or more selectable options (see DropdownOption). Dropdowns are referenced by schema field definitions (see DropdownLinkFieldDefinition) to constrain the allowed values for a field. Organizations use dropdowns to enforce standardized terminology across experiments, samples, and other registered entities.