monomorphic

Having only one form, as one crystal form.

Having or existing in only one form, as having only one allele of a gene or having males and females that look alike.

In zoology, of one and the same (or essentially similar) type of structure; formed much alike; notably uniform in morphic character: said of a number of animals collectively, or of the zoölogical group which they constitute: as, birds are a highly monomorphic class of animals.

In entomology, having but one form, structure, or morphological character; identical or invariable in form throughout successive stages of development; monomorphous; homomorphous; ametabolic.

Having but a single form; retaining the same form throughout the various stages of development; of the same or of an essentially similar type of structure; — opposed to dimorphic, trimorphic, and polymorphic.

having or existing in a single shape or form

invariant across a species

taking only a single data type