When white-eyed and miniature-winged $Drosophila$ $melanogaster$ is crossed with its wild type,it produces which of the following percentages of recombinants (in $\%$)?

Define/Explain the following terms:
$1.$ Linked genes
$2.$ Locus

Select the incorrect statement$(s)$ from the options given below with respect to dihybrid cross.
$I.$ Tightly linked genes on the same chromosome show higher recombinations.
$II.$ Genes far apart on the same chromosome show very few recombinations.
$III.$ Genes loosely linked on the same chromosome show similar recombinations.

Crossing over is

Define/Explain: Linkage.

When a test cross is performed between $F_1$ hybrid flies,the parental type offspring are produced in much higher frequency than the recombinant type offspring. What does this indicate?