(i) Three point test cross.
(ii)

If we analyse the loci of two alleles at a time, starting with AB, since AB and ab are parental genotypes, the recombination will be Ab/aB.
The recombinant frequency for these two alleles can be calculated as follows.
\(RF = \frac{Total\ no.\ of \ recombination}{Total\ no.\ of\ progenies}\times100\)
\(\mathrm{RF}=\frac{114+5+4+116}{1200} \times 100 \)
\(\mathrm{RF}=\frac{239}{1200}=19.91 \)
For A and C loci, the recombinants are Ac / aC - RF will be as follows.
\(\mathrm{RF}=\frac{114+134+116+128}{1200} \times 100 \)
\(\mathrm{RF}=\frac{482}{1200}=40.1 \)
For B and C loci, the recombinants are Bc / bC- RF will be as follows.
\(R F=\frac{124+5+4+128}{1200} \times 100 \)
\(R F=\frac{261}{1200}=21.75 \)
All the loci are linked, because all the RF value is less than 50%. In this A - and C loci show highest RF value, they must be farthest apart. Therefore B locis must lie in between them.
The order of genes should be abc. A genetic map can be drawn as follows.
(iii)
 

(i) A type of structural chromosomal abbrevation.
Reverse tandem duplication
(ii) The duplicated segment is located immediately after the normal segment but the gene sequence order will be reversed.

Missense Mutation Non-sense Mutation The mutation where the codon for one amino acid is changed into a codon for another amino acid. The mutations where codon for one amino acid is changed into a termination or stop codon.