Rough-coated guinea pigs crossed with smooth-coated ones produce only rough-coated offspring. What results would be expected from breeding here offspring with each other?
As all the offspring are rough-coated offspring, it is a dominant trait. These offspring are heterozygous. If two heterozygous organisms from the first generation are crossed, the 3:1 ratio will be observed for the second generation. There will be 3 rough-coated animals per each smooth-coated one.