There is a general assumption that all inheritance is controlled by the chromosomes of the nucleus. This is actually not the whole story. In animals the mitochondria contain their own chromosomes and in plants chloroplasts contain their own DNA. In the case of Dolly the cloned sheep, she had the DNA from the udder of her "mother" but the mitochondria of the egg donor. This means that her nuclear DNA is from one sheep while her mitochondrial DNA is from a different sheep. This difference may account for observed differences between her and her "mother" (the sheep which donated the nuclear DNA).
During World War II the Germans occupied Holland. There was a chronic food shortage which resulted in many pregnant mothers giving birth to under-weight babies. What surprised geneticists was that there was an effect on the grandchildren! Those babies are now grown up and have become mothers themselves. Despite having no food shortage their babies are being born under-weight. It would appear that the factors affecting the original war-babies have influenced the next generation too!