How many of the following statements about craniates is (are)correct?
1)Craniates are more highly cephalized than are noncraniates.
2)Craniates' genomic evolution includes duplication of clusters of genes that code for transcription factors.
3)The craniate clade is synonymous with the vertebrate clade.
4)Pharyngeal slits that play important roles in gas exchange originated in craniates.
5)The two-chambered heart originated with the early craniates.
A) one of these
B) two of these
C) three of these
D) four of these
E) five of these

Question

Quizplus · Accepted Answer

1) Craniates show a higher degree of cephalization, meaning the development of a head where sensory organs and a brain are concentrated, compared to noncraniates. 2) The genomic evolution of craniates includes the duplication of gene clusters, particularly those coding for transcription factors, which has allowed for greater complexity in development and physiological processes. 4) Pharyngeal slits, which are found in all craniates, originally played roles in filter-feeding and later in some groups, including fish, took on roles in gas exchange. 5) The two-chambered heart is a feature that originated with early craniates, facilitating more efficient circulation of blood. Statement 3 is incorrect because the craniate clade includes all vertebrates plus some additional forms that have a skull but not a full vertebral column, making it broader than just vertebrates.

How Many of the Following Statements About Craniates Is (Are)correct