When two genes are situated very close to each other in a chromosome,

Genetic recombination occurs through

What is the result of linkage and crossing over?

Incomplete linkage is $A$. Complete linkage is $B$. Choose the correct option for $A$ and $B$.

Sex-linked inheritance was discovered by

$A$ pure breeding pea plant with the dominant phenotype of character $A$ and recessive phenotype of character $B$ was crossed with another pure breeding plant with the recessive phenotype of $A$ and dominant phenotype of character $B$. An offspring of this cross was crossed with a homozygous recessive for both the characters $A$ and $B$. The following results were obtained:
$22$ were phenotypically dominant for $A$ and recessive for $B$.
$4$ were phenotypically dominant for both $A$ and $B$.
$4$ were phenotypically recessive for both $A$ and $B$.
$24$ were phenotypically recessive for $A$ and dominant for $B$.
These results show that: