11/18 quiz

Which of the following can be found in vertebrates but NOT in lancelets and tunicates?

-two or more clusters of Hox genes -duplications of genes that produce signaling molecules and transcription factors -neural crest

description of descent with modification

A trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor A shared ancestral character is a character that is not unique to a particular group, having originated in an ancestor of that group. For members of the turtle-leopard group, the phylogeny shows that a vertebral column, hinged jaws, and four limbs are all shared ancestral characters, having originated before the turtle-leopard group diverged from other lineages shown in the tree. In contrast, a shared derived character is an evolutionary novelty that is unique to a particular group; in the phylogeny shown here, an amnion is a shared derived character for the turtle-leopard group

If an animal has segments, bilateral symmetry, pharyngeal clefts, a post-anal tail, and deuterostomic development, it must be a member of the __________.

Chordata Chordates are deuterostomes that have four anatomical structures appearing at some time in development: a notochord, a hollow dorsal nerve cord, pharyngeal clefts, and a muscular post-anal tail.

Vertebrates and tunicates share

a notochord and a dorsal, hollow nerve cord.

Based on the highlighted (white) branches in the phylogenetic tree shown, which of the following labels refers to a paraphyletic group?

green algae A monophyletic group consists of an ancestral species and all of its descendants. Examples of monophyletic groups in this phylogenetic tree include red algae, plants, charophytes, chlorophytes, and the supergroup Archaeplastida. In contrast, a paraphyletic group consists of an ancestral species and some, but not all, of its descendants. In this tree, green algae are a paraphyletic group, because they consist of chlorophytes, charophytes, and their common ancestor, but not plants, which are also descended from the same common ancestor.

A __________ is a chordate but not a vertebrate.

lancelet Lancelets are cephalochordates and, throughout their life, retain the notochord as the primary support of the appendicular skeleton.

Which of the following chordate characteristics contributes most to suspension-feeding devices in many invertebrate chordates?

pharyngeal slits or clefts Derivatives of the pharyngeal slits contribute to suspension-feeding devices in many invertebrate chordates

Which of the following chordate characteristics contributes most to the formation of your ears?

pharyngeal slits or clefts In mammals, derivatives of the pharyngeal slits contribute to the development of portions of our ears

Living vertebrates can be divided into two major clades. Select the appropriate pair.

the cyclostomes and the gnathostomes

In the phylogenetic tree shown, which of the following are shared ancestral characters for members of the turtle-leopard group?

vertebral column; four limbs A shared ancestral character is a character that is not unique to a particular group, having originated in an ancestor of that group. For members of the turtle-leopard group, the phylogeny shows that a vertebral column, hinged jaws, and four limbs are all shared ancestral characters, having originated before the turtle-leopard group diverged from other lineages shown in the tree. In contrast, a shared derived character is an evolutionary novelty that is unique to a particular group; in the phylogeny shown here, an amnion is a shared derived character for the turtle-leopard group