Can organisms with the same phenotype have a different genotype? give examples

Yes, this is possible. Traits that are inherited can be dominant – that is, the main ones, they always appear if they are in the DNA; and recessive – that is, secondary. Recessive signs do not appear if dominant signs are found next to them. For example, black hair is dominant in rabbits. White is recessive. If we take several black rabbits, then among them there can be both individuals with the AA genotype (only dominant “black” genes), and individuals with the Aa genotype (heterozygous).