Test 4: Homework Assignments

The inner layer of a sponge, the mesohyl, contains several types of ________ cells, which secrete materials to form a skeleton-like structure for support.

Amoeboid

Of the many phyla falling under this clade, the ____________ contains the largest number of described species of any phylum in the animal kingdom.

Arthropod

A worm that is solid from the gut epithelium to the outermost epithelium would be considered..... A. Pseudocoelomate B. Acoelomate C. Coelomate D. Diploblastic E. Segmented

B

According to the modern classification scheme, which animal would be a spider's closest relative? A. An earthworm B. A roundworm C. A snail D. A tapeworm E. A squid

B

Given the distribution of the 30 or so animal phyla across the Earth's various ecosystems, what would be the most likely habitat for the origin of animals? A. Deserts B. Ocean C. Temperate grassland D. Rain forests E. Freshwater habitats

B

In the Bryozoa and the Brachiopoda, the lophophore is a ciliated, circular, or U-shaped structure that is used for both _________________ and __________________. A. attachment; excretion B. gas exchange; feeding C. locomotion; reproduction D. defense; orientation

B

Predict why a box jelly can eat fish while a sponge can only consume bacteria and other microscopic organic matter? A. Sponges are too small to consume large prey items. B. Box jellies start digestion in their gastrovascular cavity. C. Sponges lack venom in their stinging cells. D. Box jellies use intracellular digestion.

B

The evolutionary innovation that first appeared in arthropods and is characteristic of the most successful of all animal groups is that of..... A. segmentation. B. jointed appendages. C. bilateral symmetry. D. three primary types of tissues. E. coelomic body architecture.

B

All species of animal have general features in common. Check all of the features that would apply to animals. A. Animal cells possess a cell wall and are quite rigid. B. Most animals have the capacity for active movement. C. Animal zygotes undergo mitotic divisions called cleavage. D. Not all animals are multicellular. E. All animals produce diploid spores. F. All animals are heterotrophs.

B, C, F

Cnidarians may be found in two body forms. Which of the following statements are correct regarding cnidarians? A. Sessile group of colonial cells. B. Free-floating medsuae. C. Free-swimming bilateral larvae. D. Sessile cylindrical polyp.

B, D

An invertebrate biologist is conducting research with crabs. Her interest is ecdysis. This implies that she studies..... A. tagmatization processes in crustaceans. B. how ommatidia function individually in a compound eye. C. the molting process. D. how the HOX gene controls the fusion of the head and thorax into the cephalothorax. E. how ocelli evolved from mere photoreceptors to imaging lens.

C

Animals are thought to have descended from choanoflagellate protists. Which poriferan cell type lends evidence to this claim? A. Spicule B. Amoebocyte C. Gamete D. Choanocyte

D

Annelids and arthropods were once considered closely related. Some juvenile forms of arthropods resemble annelids (maggots and caterpillars). However, modern classification schemes separate them into distant groups. What feature suggests a fundamental difference between the two groups? A. Whether the circulatory system is open or closed B. The presence or absence of segments C. The presence or absence of a coelom D. Whether growth is continuous or step-wise

D

Arrange these animals in term of their relatedness to humans. The most closely related organisms first and the most distantly related organism last. A. Sponge, sea star, crab, jellyfish, flatworm. B. Acoel flatworm, crab, sponge, sea star, jellyfish. C. Sponge, acoel flatworm, crab, sea star, jellyfish. D. Sea star, crab, acoel flatworm, jellyfish, sponge. E. Crab, sea star, jellyfish, acoel flatworm, sponge.

D

In the current animal classification system __________ is thought to have originated once, and ____________ is thought to have evolved multiple times. A. Segmentation, molting B. Molting, bilateral symmetry C. Bilateral symmetry, molting D. Molting, segmentation

D

In what way are a human and a crab similar? A. Both have a continuous growth pattern. B. Both have closed circulatory systems. C. Vertebrates and arthropods are deuterostomes. D. Both have muscles that pull against rigid skeletons.

D

Paramecia use cilia for locomotion and for gathering organic matter. How are rotifers similar? A. Rotifers and ciliates are thought to have given rise to all other animal phyla. B. Rotifers are single-celled protists. C. Both lack a gut. D. The corona is made of cilia, and used for swimming and feeding.

D

The lophophore of a brachiopod serves the same function as the __________ in a bivalve. A. Foot B. Shell C. Mantle D. Gills

D

The ____________ is the principal structure used by mollusks to maintain osmotic balance.

Nephridium

The two largest clades in the Bilateria are the protostomes and the deuterostomes. True or false.

True

Mollusks have centralized digestive, excretory, and reproductive systems within a ____________ .

Visceral mass

Partitions isolate each segment, so each must contract or expand in unison. True or false.

False

Redundancy in segmented animals is not an advantage. True or false.

False

The arthropods are the most successful group of animals; several key features explain their success. Check all of the features that one would use to classify members into this phylum. A. Growth takes place through ecdysis. B. A rigid exoskeleton made of chitin. C. Closed circulatory systems. D. Jointed appendages. E. A rigid exoskeleton made of keratin. F. Segments specialized into functional tagmata.

A, B, D, F

A biologist looking for distinguishing traits for chordates would choose...... A. pharyngeal slits or pouches. B. possession of an endoskeleton. C. segmentation. D. indeterminate radial cleavage in the early embryo. E. possession of a backbone.

A

Choanocytes A. filter particles out of the water. B. secrete the mesohyl. C. produce the spicules. D. make the spongin protein.

A

Segmentation is the subdivision of the body into segments. True segmentation is found in which of the following phyla? A. Arthropoda, Annelida, Chordata. B. Echinodermata, Platyhelminthes, Cnidaria. C. Mollusca, Chordata, Annelida. D. Annelida, Mollusca, Arthropoda. E. Arthropoda, Chordata, Porifera.

A

What do echinoderms and chordates have in common? A. Endoskeletons B. Ecdysis C. Dorsal nerve cords D. Protostome development

A

Which feature would only be found in the Bilateria? A. Anterior cephalization B. Nerves and sensory systems C. Extracellular digestion D. Sexual reproduction

A

The chordates share several features that have played a significant role in the evolution of the phylum. Check all of the features that one would use to exclusively classify members of Chordata and not members of Echinodermata. A. A postanal tail during embryonic development. B. Pharyngeal pouches during embryonic development. C. An endoskeleton D. A notochord on the dorsal side of the gut in the early embryo. E. Deuterostomic development of the embryo. F. A hollow nerve cord.

A, B, D, F

Bivalves lack a radula. How do they eat? A. Most bivalves have photosynthetic endosymbionts in the visceral mass. B. Inhalent siphons suck water into the mouth. C. The gills filter water and extract organic matter. D. The mantle traps and moves sediment to the stomach for digestion.

C

In terms of the number of species, the most successful class of arthropods is.... A. Chilopoda. B. Crustacea. C. Hexapoda. D. Myriapoda. E. Chelicerata.

C

Pinworm is a nematode parasite that lives in the human rectum and causes itching in the anal area. What best explains the itching symptom? A. The itching is a side-effect when the immune system has successfully attacked the nematode. B. The itching is because of the mismatch between humans and the parasite's natural host. C. The itching induces the person to scratch, helping to spread the parasite to another person. D. Any kind of parasite will naturally irritate the skin.

C

Select the true statements concerning echinoderms. A. They have an exoskeleton made of hardened calcium carbonate plants. B. Echinoderms have radially symmetrical larvae that give rise to bilaterally symmetrical adults. C. Tube feet are used for locomotion and grasping objects. D. Echinoderms are well represented in the fossil record. E. The blastopore of a sea star becomes its anus.

C, D, E

__________ are flagellated cells that line internal cavities and are responsible for pumping water and small particles into the sponge.

Choanocytes

What are some descriptions of deuterostomes?

Coelom forms from cells that pouch off the end of the archenteron, indeterminate development, radial cleavage, and blastopore becomes anus.

Members of this phylum are ____________ animals with jointed appendages and segmented external skeletons composed of chitin.

Coelomate

What animals are considered to be protostomes (Ecdysozoa)?

Crustacean and onlychophora

What are the three animal phyla that dominate animal life on land? A. Cnidaria, Mollusca, Platyhelminthes. B. Porifera, Arthropoda, Nematoda. C. Platyhelminthes, Nematoda, Arthropoda. D. Mollusca, Arthropoda, Chordata. E. Nematoda, Chordata, Cnidaria.

D

Which of the following terms is mismatched with its meaning or characteristics? A. Eumetazoa: definite symmetry; tissues organized B. Parazoa: lacks symmetry; no tissues C. Chordate: animal with notochord D. Diploblastic: ectoderm and mesoderm E. Triploblastic: ectoderm, mesoderm, and endoderm

D

Sponge cells are unique because throughout their development they can ____________ from one type of cell to another.

Differentiate

Molecular data confirm that cnidarians branched off from the rest of animals before ____________ evolved. A. arthropods B. mollusks C. Porifera D. echinoderms E. bilaterial symmetry

E

Select the following phylum that includes animals that are unsegmented, acoelomate, and have a digestive cavity with a single opening. A. Annelida B. Cnidaria C. Rotifera D. Nematoda E. Platyhelminthes

E

Select the following phylum that includes coelomate, bilaterian animals that have a structure called a notochord. A. Arthropoda B. Mollusca C. Echinodermata D. Annelida E. Chordata

E

Which one of the following terms applies to the phylum Cnidaria? A. Parazoa B. Triploblastic C. Protostome D. Pseudocoelomate E. Radial symmetry

E

What animals are considered to be protostomes (Spiralia)?

Earthworm, planarian, snail, and bryozoan.

The ____________ animals are protostomes that grow step-wise by a process called molting.

Ecdysozoan

The exterior of a sponge is composed of flattened cells that form an outer ________.

Epithelium

There are two main groups in this clade: the ____________ and the Platyzoa.

Lophotrochozoa

Mollusks have a thick epidermal sheet or ____________ , which covers the dorsal side of the body.

Mantle

Sponges are truly ______ organisms.

Multicellular

The ____________ has been adapted for a number of different functions across the phylum including locomotion, attachment, feeding, and digging.

Muscular foot

Many mollusks feed using a rasping, tonguelike structure called the ____________ .

Radula

What animals are considered to be deuterostomes?

Sea star, human

What are some descriptions of protostomes?

Spiral cleavage, blastopore becomes mouth, coelom forms from mesodermal cells that move apart from one another to create an expanding cavity within the mass of the cells, and determinate development.

The ____________ animals are protostomes that grow by gradual additions of mass to the body.

Spiralian

In segmented animals like earthworms (phylum Annelida), each segment may develop a nearly complete set of adult organ systems. True or false.

True

Locomotion is more efficient in segmented animals because independent segments can move semi-independently. True or false.

True