Answer:  TO UNDERSTAND THIS YOU MUST BE FAMILIAR WITH MEIOSIS 1&2    BELIEVE ME ITS VERY IMPORTANT

ACTUALLY DROSOPHILA flies are ightly linked together

Explanation:

the drosophila cross did not followed law of INDEPENDENT assortment thats why , scientist came up with the term linkage , scientist name was th morgan

what they found was the phenotypic ratio was different from 9:3:3:1

it was infact 3:1(due to linkage)

linked genes does not show recombination thats why parental ganes are present more

before i  proceed further you should be clear that linkage is nothing but association of two genes

in fruit flies normal wings are dominant over vestigial wings while gray colour is dominant over the black colour suppose that shape of wings is linked to colour trait

replication first takes place

during meiosis 1 sunapsis between homologous(non sister CHROMATIDS)this produces geneticallyrecombinant chromosomes

AFTER THIS - SYNAPSES TAKES PLACE THEN CROSSING OVER TAKES PLACE

REFER TO IMAGE\

when genes are tightly linked even lesser recombinant takes place

what you asked is about eye and BODY   actually these genes are tightly linked and crossing over faces difficulty so genes are not recombinated actually

the image is for loosely linked genes