BSC 117 midterm 2 homework study questions

Which of the following are characteristics of arthropods? 1. protostome development 2. bilateral symmetry 3. a pseudocoelom 4. three embryonic germ layers 5. a closed circulatory system

1, 2, and 4

Animal tissues develop from embryonic germ layers. Triploblastic animals have three germ layers (ectoderm, mesoderm, and endoderm) and three basic body plans related to body cavities (acoelomate, pseudocoelomate, and coelomate). Select the three statements that are true. To review the germ layers and the terminology associated with body cavities,

1. A diploblast has no mesoderm. 2. In a coelomate, the tissue lining the inner side of the body cavity arises from the same germ layer as the tissue lining the outer side of the body cavity. 3. A pseudocoelom has the same functions as a true coelom.

With the current molecular-based phylogeny in mind, rank the following from most inclusive to least inclusive. 1. ecdysozoan 2. protostome 3. eumetazoan 4. triploblastic

3, 4, 2, 1

Which of the following statements is correct? Eumetazoans have true tissues. Sponges are basal animals. Most animal phyla belong to the clade Bilateria. All animals share a common ancestor. All of the choices are correct.

All of the choices are correct

Identify the features that distinguish animals from organisms in other multicellular kingdoms. Animals are ingestive heterotrophs. Animals are motile. Animals have sensory organs at their anterior end.

Animals are ingestive heterotrophs.

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

Cambrian

A graduate student finds an organism in a pond and thinks it is a freshwater sponge. A postdoctoral student thinks it looks more like an aquatic fungus. How can they decide whether it is an animal or a fungus? (Concept 32.1)

Look for cell walls under a microscope.

The heartworms that can accumulate within the hearts of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong? Acoela Nematoda Arthropoda Annelida Platyhelminthes

Nematoda

All animals can trace their lineage to a common ancestor that lived in the _____. (Concept 32.2)

Neoproterozoic era

The animal phylum most like the protists that gave rise to the animal kingdom is _____. Echinodermata Cnidaria Porifera Ctenophora Lycophyta

Porifera Evidence that supports this includes the lack of true tissue in sponges and the close similarity between choanocytes and choanoflagellates.

In the traditional phylogeny (Figure A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla, and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (Figure B), Platyhelminthes is depicted as a lophotrochozoan phylum. What probably led to this change?

The removal of the acoel flatworms (Acoela) from the Platyhelminthes allowed the remaining flatworms to be clearly tied to the lophotrochozoa.

Which of the following is not a characteristic of all animals? They have tissues, organs, and organ systems. They are all multicellular. They are eukaryotes. They are heterotrophic. They ingest their food.

They have tissues, organs, and organ systems.

Which one of the following animals is an annelid? a tapeworm a leech a caterpillar flatworm a squid

a leech

A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and an open circulatory system, but no skeleton. Based on this, you determine that the animal must be a(n) _____. roundworm lancelet mollusc crustacean annelid

annelid

Members of the phylum Mollusca _____ are soft-bodied and usually covered by a shell include polychaete worms and leeches have segmented bodies and paired, jointed appendages include arthropods include annelids

are soft-bodied and usually covered by a shell

What structure is responsible for gas exchange in most spiders? (Concept 33.4) tracheal tubes Malpighian tubules the pedipalp chelicerae book lungs

book lungs -The extensive surface area of book lungs is a structural adaptation that enhances the exchange of O2 and CO2 between the hemolymph and air.

Which of the following are elongated in the oral-aboral axis? class Holothuroidea (sea cucumbers) class Ophiuroidea (brittle stars) class Asteroidea (sea stars) class Crinoidea (sea lilies and feather stars) class Echinoidea (sea urchins and sand dollars)

class Holothuroidea (sea cucumbers)

Which of the following are entirely, or partly, composed of calcium carbonate? Which of the following are entirely, or partly, composed of calcium carbonate? nematodes' cuticles insects' cuticles spicules of siliceous sponges coral animals' exoskeletons molluscs' mantles

coral animals' exoskeletons

Humans most frequently acquire trichinosis by eating undercooked beef. being bitten by tsetse flies. having sexual contact with an infected partner. inhaling the eggs of worms. eating undercooked pork.

eating undercooked pork.

Which of the following animals does not have a body cavity? clam earthworm flatworm mouse ant

flatworm

Which of the following is a characteristic of cnidarians? an anus radula mesoderm gastrovascular cavity bilateral symmetry

gastrovascular cavity The gastrovascular cavity, characterized by a single opening, is the digestive compartment of cnidarians.

An important trend in animal evolution was cephalization. An animal is said to show cephalization when it _____.

has an aggregation of sensory neurons at the anterior end

During embryological development, the anus forms before the mouth in _____. humans earthworms flatworms slugs arthropods

humans During gastrulation, the developing digestive tube of the embryo initially has a single opening, the blastopore. After the archenteron develops, a second opening forms at the opposite end of the gastrula. The mouth of many protostomes develops from the first opening, whereas in deuterostomes the mouth is derived from the second opening.

Ectoprocts and brachiopods are collectively referred to as _____. cephalopods eumetazoans flatworms trochophorates lophophorates

lophophorates -The lophophore is a structure common to these three phyla that bear ciliated tentacles.

Some species of rotifers consist solely of females. Their method of reproduction is described as _____.

parthenogenesis The females lay unfertilized eggs that develop into females.

Gastrulation is the process that directly forms the _____.

primary germ layers

Which of the following are thought to be most closely related to humans? (Concept 33.5) snails sea stars jellies earthworms ants

sea stars Humans and sea stars are deuterostomes.

Which one of the following is characteristic of the phylum Platyhelminthes? they are all parasitic they are diploblastic they typically reproduce asexually they are dorsoventrally flattened they are radially symmetrical

they are dorsoventrally flattened

Which of the following characteristics most likely explains why insects are so successful at dispersing to distant environments? jointed appendages hemocoel wings chewing mandibles internal fertilization

wings