The crossing of a hybrid and a dominant purebred will always result in offspring which are what?

Dominant

Explanation:

A hybrid trait is also known as heterozygous, which is the combination of the dominant and recessive alleles of a gene. On the other hand, a purebred is combination of the same two dominant alleles or the same two recessive alleles. For example, in the gene coding for height, allele for tallness (T) is dominant over the allele for shortness (t).

A purebred for this trait will either be "TT" or "tt" while a heterozygous or hybrid will be Tt. Hence, according to this question, crossing of a hybrid (Tt) and a dominant purebred (TT) will always result in offspring which are DOMINANT (see attached image).

chordata is the answer