This question involves a single gene coding for hair length in guinea pigs. Based on the information in this question, the allele for short hair (S) is dominant over the allele for long hair (s). This means that a guinea pig will only be phenotypically long-haired if the genotype is "ss".
According to this question, Two short-haired guinea pigs are mated several times. Out of the 100 offsprings produced by this cross, 25 of them have long hair (recessive). This means that the phenotypic ratio of this cross is 3 short hair : 1 long hair i.e. 100 - 25 = 75 short hair. 75/25 = 3/1 = 3:1
To produce this phenotypic ratio, the parents must both be heterozygous (Ss) for the hair length gene.
Based on the Scenario, the process is described as Mitosis
During this process , chromosomes in a cell nucleus will be separated into two identical set of chromosomes (which make it four) and will end up in their own nucleus