Crossing over is

The percentage of crossing over will be more if:

As the length of the chromosome increases in an organism,which of the following increases?

In a somatic cell,if the arrangement of genes is such that dominant alleles are present on one chromosome and recessive alleles are present on the other chromosome of a homologous pair,what is this arrangement called?

$T.H.$ Morgan worked with $Drosophila$ to prove the chromosomal theory of inheritance. Which of the following characteristics was $NOT$ present in $Drosophila$?

Select the correct statement from the ones given below with respect to dihybrid cross.