Use the diagram above to answer this question. Which of the following will be true of dog ll which lost its tail in an accident if it mates with dog lll.

Answer Details

None of its offspring will be born without a tail. The presence or absence of tails in dogs is a trait that is controlled by a single gene, with the dominant allele (T) producing tails, and the recessive allele (t) producing no tails. The diagram shows that dog II is heterozygous for this gene, meaning it carries one copy of the dominant allele and one copy of the recessive allele (Tt), and dog III is homozygous recessive (tt). When dog II mates with dog III, their offspring will inherit one allele from each parent. The Punnett square below shows the possible genotypes and phenotypes of their offspring: | | T | t | |---|---|---| | t | Tt| tt| | t | Tt| tt| As you can see from the Punnett square, all of the offspring will inherit one copy of the dominant T allele from dog II, and therefore they will all have tails. However, since dog II is heterozygous, 50% of the offspring will carry the recessive t allele, even though they have tails. If two of these tail-carrying offspring were to mate in the future, they could produce some offspring without tails. Therefore, none of the offspring from the mating of dog II and dog III will be born without tails, but some of them will carry the recessive allele for taillessness and could produce tailless offspring in the future if they mate with another carrier.