Which one of the following is exclusively applicable for genes
(1)Occur in pair
(2)Segregate at the time of gamete formation
(3)Indepent pairs segregate independently of each other
(4)One pair segregate independently from other pair
Please explain the last two statements. Also in NCERT pg 82, what is A and B?

Option 4 is exclusively for genes. on Page no 82 in table the A is for chromosome and B is for gene. In the table first two points are same for both gene and chromosome as genes are located on chromosome. Both occur in pair. It is the pairing and segregation of the pair of chromosomes that leads to segregation of the pair of factor, so the 4 th point is applicable for genes.