practice for 11/11

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.

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.

Which of the following statements is the most inclusive description of descent with modification? A trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor. Natural selection leads to the evolution of similar features in independent evolutionary lineages. Similarity between two species results from genetic drift in small populations. Similarity between two species results from convergent evolution.

A trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor.

If an animal has segments, bilateral symmetry, pharyngeal clefts, a post-anal tail, and deuterostomic development, it must be a member of the __________. (Concept 34.1) Platyhelminthes Annelida Arthropoda Mollusca Chordata

Chordata

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.

Pharyngeal slits

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

A trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor.

Evolution is a process of descent with modification: Characteristics present in an ancestral organism are altered in its descendants over time as they face different environmental conditions. One result of descent with modification is that related species can have characteristics that have an underlying similarity yet different functions. Descent with modification occurring in different evolutionary lineages may result in species in each of those lineages having characteristics that function similarly yet are not due to common descent as those species have independently adapted to similar environmental conditions.

Which of the following pairs is not a correct match? (Concept 34.2) Gnathostomata, hagfish Mammalia, kangaroo Aves, canary Chondrichthyes, great white shark Osteichthyes, perch

Gnathostomata, hagfish

Gnathostomata, hagfish

Gnathostomes are jawed vertebrates. A hagfish is an agnathan, a jawless vertebrate.

Pharyngeal clefts

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

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 the formation of your ears? (Concept 34.1) Muscular, post-anal tail Pharyngeal clefts Dorsal, hollow nerve cord Notochord None of the listed responses is correct.

Pharyngeal clefts

Which of the following chordate characteristics contributes most to suspension-feeding devices in many invertebrate chordates? (Concept 34.1) Notochord Pharyngeal slits Muscular, post-anal tail Dorsal, hollow nerve cord None of the listed responses is correct.

Pharyngeal slits

As hominins diverged from other primates, which of the following appeared first? the making of stone tools an enlarged brain bipedal locomotion reduced jawbones

bipedal locomotion

Based on the highlighted (white) branches in the phylogenetic tree shown, which of the following labels refers to a paraphyletic group?[Diagram showing a series of white horizontal forked branches. Reading left to right, the first branch point forks into a horizontal line leading to Red algae and another horizontal line, which branches again. This second branch point forks into a horizontal line leading to Chlorophytes and another horizontal line, which branches again. This third branch point forks into a horizontal line leading to Charophytes and another horizontal line leading to Plants. The Chlorophyte and Charophyte branches together are labeled Green algae. At the far right of the diagram a vertical label Archaeplastida extends from the Red algae down through the Plants.] green algae red algae plants Archaeplastida

green algae

A __________ is a chordate but not a vertebrate. (Concept 34.1) lamprey frog lancelet sea star shark

lancelet

In the phylogenetic tree shown, which of the following are shared ancestral characters for members of the turtle-leopard group?[Diagram showing a series of horizontal forked branches. Reading left to right, the first branch point forks into a horizontal line leading to Lancelet (outgroup) and another horizontal line which has a vertical hatch mark labeled Vertebral column, and then branches again. This second branch point forks into a horizontal line leading to Lamprey and another horizontal line which has a vertical hatch mark labeled Hinged jaws, and then branches again. This third branch point forks into a horizontal line leading to Bass and another horizontal line, which has a vertical hatch mark labeled Four limbs, and then branches again. This fourth branch point forks into a horizontal line leading to Frog and another horizontal line, which has a vertical hatch mark labeled Amnion, and then branches again. This fifth branch point forks into a horizontal line leading to Turtle and another horizontal line, which has a vertical hatch mark labeled Hair and leads to Leopard.] vertebral column; amnion vertebral column; four limbs four limbs; hair hinged jaws; amnion

vertebral column; four limbs