Question

Definition of directional structure

Answer 1

Any sedimentary structure having directional significance; examples are cross-bedding and ripple marks. Also known as vectorial structure. now that's a real answer

Answer 2

These charts depict the different types of genetic selection. In population genetics, directional selection is a mode of natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype.