Question

when doing a gene map, it is wise step to always start with the frequency of recombination. middle highest 50% lowest

Explanation:

When constructing a gene map, the recombination frequency reflects the distance between genes. Genes that are closer together have a lower recombination frequency. Starting with the lowest recombination frequency helps in accurately mapping the relative positions of genes as it indicates the closest - lying gene pairs.

Answer:

Lowest