The dwarfness in plants of $F_2$ generation is

$XO$ type of sex determination can be found in:

Which one of the following mutation partially or fully reverses the harmful effects of previous mutation

___$(B)$___ used the frequency of recombination between gene pairs on the ___$(A)$___ as a measure of the distance between genes and mapped their position on the chromosome

$(A) \;\;\quad\;\;(B)$

A tobacco plant which is heterozygous for albinism $(a\, recessive\,character)$ is self pollinated if $1200$ seeds are subsequently germinated, how many of the seedlings would have the parental genotype