Mastering Biology Chapter 27

Which of the following statements about deuterostomes is false?

All deuterostomes exhibit radial symmetry in their bodies

Identify the features that distinguish animals from organisms in other multicellular kingdoms

Animals are ingestive heterotrophs

Which feature of deuterostome development explains the formation of identical human twins?

Deuterostomes have indeterminate development.

Select the correct statement(s) about animal body plans.

Development in all animals is determined by the unique family of Hox genes (or other similar homeobox genes).

What is the significance of the evolution of Hox gene clusters during vertebrate evolution?

Duplication of Hox genes made increased morphological complexity possible.

Select the correct statement(s) about invertebrate taxa.

Ectoprocts lack a distinct head. Rotifers are smaller than many protists. Tapeworms lack a mouth and gastrovascular cavity.

Which of the following chordate groups include(s) humans?

Gnathostomes Amniotes Hominins

Select the vertebrate taxon or taxa whose origin(s) involved duplication of Hox genes.

Gnathostomes Craniates

Which of the following statements describing hominin evolution is/are correct?

Homo sapiens is the only surviving member of a highly branched evolutionary tree of hominin species.

Which clade does NOT include humans?

Lophotrochozoans

Which of these primate groups lives in trees in Central and South America and have nostrils that are wide open and far apart?

New World Monkeys

What is the key difference between a coelom and a pseudocoelom?

Only a coelom is fully lined with mesoderm tissue.

Which structure can be used for feeding and gas exchange?

Pharyngeal gill slit

The animal phylum most like the protists that gave rise to the animal kingdom is _____.

Porifera

_____ are the oldest known primate group.

Prosimians

All chordates share a set of derived characters during at least some part of their life.

Refer to image

What evidence suggests that vertebrates are more closely related to echinoderms than are any other invertebrate phyla?

Shared DNA sequences

Select the correct statement(s) describing nematodes.

Some nematodes play important roles in nutrient cycling. Nematodes lack a circulatory system and circular body wall muscles.

Scientists have concluded that bdelloid rotifers have likely been asexual for 100 million years. What evidence supports this conclusion?

The comparison of the DNA of bdelloids and that of sexually reproducing rotifer species

Select the correct statement about the evolution of animals.

The oldest generally accepted fossils of large animals range in age from 565 to 550 million years old.

Which characteristics define a chordate?

The presence of four specific morphological traits

Louis and Mary Leakey found two different fossil hominid skulls at Olduvai. Which of the following statements about the skulls is true?

The second skull represented a species more closely related to modern humans than the first skull's species.

Which of the following is NOT a characteristic of all animals?

They have tissues, organs, and organ systems.

Some invertebrates combine morphological simplicity with features of great structural or biochemical complexity. Select all correct examples of this statement.

Trematodes are acoelomates that have effective defenses against attack by their hosts' immune system. Cnidarians are diploblasts that produce complex, capsule-like organelles.

In a phylogenetic tree, a lineage that diverges from all other members of its group early in the evolutionary history of the group is described as

a basal taxon.

Which of the following could be considered the most recent common ancestor of living tetrapods?

a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates

Which of the following chordates is least likely to look like other chordates?

adult tunicate

Listed below are four adaptations of terrestrial vertebrates. Which is a characteristic only of truly terrestrial animals with NO need to return to water at any stage of the life cycle?

amniotic eggs

Which of the following groups contains members most closely associated with a wet or moist environment?

amphibians

The diagnostic feature of Chondrichthyes is __________.

an endoskeleton of cartilage

Which of these primate groups is most closely related to humans?

apes

Members of the phylum Mollusca __________

are soft-bodied and often covered by a shell

Fossil steroid and molecular clock evidence suggests that animals originated __________.

between 710 and 770 million years ago more than 100 million years before the oldest known fossils of large animals

Which of the following shared characteristics of living birds and theropod dinosaurs provided support to the hypothesis that birds evolved from dinosaurs?

birds and theropods have S-shaped necks birds and many theropods have a wishbone (or furcula) birds and theropods have hollow bones that are strong, but light birds and many theropods have feathers

The earliest ancestors of about half of all extant animal phyla can be traced back to the __________ explosion.

cambrian

Which of the following is radially symmetrical?

doughnut

Which structure is not an innovation that occurred during vertebrate diversification?

exoskeleton

Which of the following is a characteristic of cnidarians?

gastrovascular cavity

An important trend in animal evolution was cephalization or development of a "head." An animal is said to show cephalization when it __________

has an aggregation of sensory structures at the anterior end

Which of the following is the most inclusive term for an organism that obtains organic food material by eating other organisms or substances derived from them?

heterotroph

The primates that spend the most time walking upright are the _____.

hominids

Which of the following traits can be used to differentiate humans from our closest living primate relatives?

large brain size extensive tool use bipedality (the ability to walk exclusively on two legs)

Ectoprocts and brachiopods are collectively referred to as __________

lophotrochozoans

There are three major groups of mammals, categorized on the basis of their __________.

method of reproduction

Which of these anthropoid groups consists of primates who are mostly tree dwellers and whose forelimbs and hind limbs are about equal in length?

monkeys

Which of the following are thought to be most closely related to humans?

sea stars

A key characteristic of modern birds is flight powered by feathered wings. Which of the following pieces of evidence support the hypothesis that the first feathers served a purpose other than flight?

some feathered theropods were not capable of flight

Which of the following clades contains the greatest number of animal species?

the bilaterians

Which of the following was probably the LEAST important factor in bringing about the Cambrian explosion?

the movement of animals onto land

Which of the following is NOT a diagnostic feature of the Chordata?

vertebrae

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

vertebral column; four limbs