Why do scientists try to repeat other scientists experiments

Ineed with a hypothesis my question is can seeds sprout in different locations?

The offspring of a black cat and a white cat is a gray cat, it has the genotype bw if a black cat mates with a gray cat the chance that the offspring is white will be what percent?

The diagram shows the results when two parents are crossed. the letters represent alleles for a trait that is controlled by three different genes. which best describes this inheritance pattern? multiple allele because a trait is controlled by three different genes polygenic because the offspring have alleles from both parents multiple allele because the offspring have alleles from both parents polygenic because a trait is controlled by three different genes