Chapter 44: Learning Curve

Which of the following numbered statements describes what phylogenetic trees help us understand? 1 : the genetic relationships among a species. 2 : the evolutionary relationships among a species. 3 : the relationships of symmetry among related species. 4 : the level of complexity among related species. 2 and 4 2 and 3 3 and 4 1 and 2

2 and 4

Egg laying is a character unique to which groups of animals and their ancestors? birds mammals reptiles All of these choices are correct.

All of these choices are correct

Which of the following is not a characteristic feature of chordates during development? notochord neural tube myotomes All of these choices are correct.

All of these choices are correct

_____ are not helpful for reconstructing evolutionary relationships because they do not show the evolutionary development of characters among groups. Analogies Homilies Similes Homologies

Analogies

Which of the following is false regarding cnidarians? Cnidarians have a separate opening for the anus and the mouth. Many cnidarians are predators rather than passive filter feeders Cnidarians have a wider variety of cells types than sponges—allowing more sophisticated tissue function. They have an outer epidermis and inner endodermis, in between which is a gelatinous mesoglea.

Cnidarians have a separate opening for the anus and the mouth

Which of the following statements is true of both mollusks and annelids? The adult body plans of mollusks (especially gastropods) and annelids are remarkably similar. Both mollusks and annelids possess mantles and gizzards. During development, both annelids and mollusks form trochopore larvae. Both annelids and mollusks lack a "flow-through" gut. All of these choices are correct.

During development, both annelids and mollusks form trochopore larvae

_____ are helpful for reconstructing evolutionary relationships because they show the evolutionary development of characters among groups. Homilies Homologies Similes Analogies

Homologies

Which of the following statements is true of sponges? Sponges have nerve cells that enable them to sense their environment. Like cnidarians, many sponges produce toxin-generating nematocysts. These cells typically line the pores of sponges. The choanocytes of sponges and choanoflagellates share no morphological similarities. Like comb-jellies, sponges possess both a mouth and an anal pore; however, the anal pore is distinctly smaller than the mouth. None of the answer options is correct.

None of the answer options is correct

Which of the following statements is false about sponges? Mesohyl is mostly noncellular and provides structural support. Choanocytes have flagella that beat in a coordinated fashion. Sponges are among the most primitive organisms to have developed reproductive organs. Gas exchange of oxygen and carbon dioxide occurs through diffusion.

Sponges are among the most primitive organisms to have developed reproductive organs.

A researcher is culturing cells in a petri dish. After a few weeks, she notices that these cells have formed a "sheet," with junctions visible between individual cells. Which of the following statements is false regarding these cultured cells? These cells have formed mesoglea. These cells have formed an epithelium. These cells have formed a structure similar to the epidermis or endodermis of jellyfish. These cells may secrete enzymes or extracellular matrix proteins into their environment. None of the answer options is false.

These cells have formed mesoglea.

Approximately 360 million years ago, flying insects reached massive sizes (by today's standards). Why are modern-day insects so small compared to their ancestors? Flying insects actually never attained large sizes; large sizes are not conducive to flight, especially in animals that possess exoskeletons. Three hundred and sixty million years ago, Earth's atmosphere had much more oxygen. Today's lower oxygen levels cannot support large insects, so smaller insects were selected for. The first flowering plants that appeared on Earth were small in size. Insects evolved to utilize these food sources, becoming smaller in the process. Larger insects were more susceptible to predation; as more predators evolved on Earth, insects became smaller in size. As tetrapods appeared on Earth, these animals competed with insects for food sources. As the amount of food decreased, so did the size of most insects.

Three hundred and sixty million years ago, Earth's atmosphere had much more oxygen. Today's lower oxygen levels cannot support large insects, so smaller insects were selected for.

All echinoderms (sea stars and sea urchins) have: a cardiovascular circulatory system and five-fold symmetry. a water vascular system and five-fold symmetry. a cardiovascular circulatory system and bilateral symmetry.

a water vascular system and five-fold symmetry.

All lophotrochozoans have: bilateral symmetry and complex organs. bilateral symmetry and primitive organs. radial symmetry and primitive organs. radial symmetry and complex organs.

bilateral symmetry and complex organs.

Refer to the Figure 44.1. To which group are sponges more closely related? Click to view full size. bilaterians equal relationship to both choanoflagellates and bilaterians choanoflagellates

bilaterians

Placozoans: are remarkable for their tissue complexity and organ development. can reproduce sexually or asexually. bear little to no resemblance to animals such as cnidarians on the basis of genetic analysis.

can reproduce sexually or asexually.

Which of the following is not a component of some sponge skeletons? calcium carbonate (CaCO3) glass-like silica (SiO2) protein cartilage

cartilage

A phylogenetic tree is a hypothesis of the: genetics of a single species. evolutionary relationships among different species. evolutionary relationships among groups of trees. genetics of trees.

evolutionary relationships among different species.

The division of bilaterians into coelomate, acoelomate and pseudocoelomate groups is supported by molecular studies. true false

false

Vertebrates may have an external skeletal system. true false

false

Which of the following is not a cell or structure found in sponges? pore gastric cavity choanocyte mesohyl

gastric cavity

Crustaceans: have radial body symmetry. include animals such as the nautilus and squid. include animals such as spiders and scorpions. have a hard external skeleton composed chitin.

have a hard external skeleton composed chitin

Insects: have a respiratory system with spiracles connecting to tracheae. typically mate and produce young during their larval stage. generally give birth to live young. typically have a younger flying life stage and an older aquatic life stage after metamorphosis.

have a respiratory system with spiracles connecting to tracheae

Ctenopores (comb-jellies): are usually filter feeders that attach themselves to the ocean bottom. have a separate epidermis and endodermis, which cnidarians lack. are a type of bilaterian. have a separate mouth and anal pore, unlike cnidarians.

have a separate mouth and anal pore, unlike cnidarians

Bilaterians are distinguished by: radial symmetry that results in multiple planes of symmetry. circular symmetry, which allows for multiple planes of symmetry and a head and tail. no symmetry, which allows for a distinct head and tail. mirror symmetry that results in a distinct head and tail and one plane of symmetry.

mirror symmetry that results in a distinct head and tail and one plane of symmetry

Marsupials: may reproduce via asexual reproduction. nurse their young. lay eggs. are only found today in Australia.

nurse their young.

What feature of animals enabled them to diversify in ways that plants, fungi, algae, and protozoans have not? radial symmetry bilateral symmetry organ systems phylogenetic analysis

organ systems

Linnaeus sorted animals into groups based on body plans. Today, these groupings are called: families. branches on the phylogenetic tree. phyla.

phyla

Many groups of organisms are defined by the unique characters they possess. The relative timing of when a particular character arose can be estimated by determining: presence of the character in only the most recent species to have it. shared presence of the character in descendants of the population who did not have the character. shared presence of the character in descendants of the population in which the character first arose. how long the character was in the population.

shared presence of the character in descendants of the population in which the character first arose

Triploblastic organisms give rise to ______ germ layers, called the _______. two; ectoderm and endoderm three; ectoderm, metoderm, and endoderm two; endoderm and mesoderm three; ectoderm, mesoderm, and endoderm

three; ectoderm, mesoderm, and endoderm

Coral reefs and tropical rain forests have existed on Earth for hundreds of millions of years, but the taxonomic composition of both has varied enormously. true false

true

Ecdysozoans include insects and make up more than half of all known animal species. true false

true

Fossils can take many forms and are not always skeletal remains. Fossils can include burrows left by animals. true false

true

Lobe-finned fish (coelacanth and lungfish) are the fish most closely related to tetrapods. true false

true

Chordates include: tunicates and vertebrates. mollusks and cnidarians. tunicates and echinoderms. cephalochordates and arthropods.

tunicates and vertebrates

Imagine that scientists have discovered annelid life on a new planet. Remarkably, these worms are large in size, lack mouths, and appear to form symbioses with certain bacterial species. These worms most resemble _____ on Earth. mollusks vestimentiferan worms polychaete worms earthworms leeches

vestimentiferan worms