Biology 221 Test # 3

Which of the following is a characteristic of cnidarians?

The gastrovascular cavity, characterized by a single opening, is the digestive compartment of cnidarians. Provide FeedbackContinue Correct. Followup. The gastrovascular cavity, characterized by a single opening, is the digestive compartment of cnidarians. End of followup.

Which of these statements is true of earthworms?

They have a body cavity.

Which of these statements is true of nematodes?

They have a digestive system with two openings.

Which of these statements is true of sponges?

They have no true tissues.

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 a closed circulatory system, plus multiple true coeloms. Based on this, you determine that the animal must be a(n)

annelid

Nematodes are most closely related to _____.

arthropods

The apparent symmetry of adult sea stars is most similar to the actual body symmetry of _____

cnidarians

Part K As adults, sea stars _____.

exhibit imperfect radial symmetry

Which of the following is characteristic of the phylum Platyhelminthes?

flatworms

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

Coelomates

have an internal body cavity surrounded inside and outside by mesoderm-derived tissues.

Pseudocoelomates

have an internal body cavity that is surrounded by mesoderm-derived tissue on the outside and by endoderm-derived tissue on the inside

Triploblasts

have tissues derived from three embryonic germ layers: endoderm inside, ectoderm outside, and mesoderm in the middle. The three basic body plans of triploblasts relate to the presence or absence of a body cavity. •No body cavity: acoelomate •Body cavity lined on the inner side by endoderm-derived tissue and on the outer side by mesoderm-derived tissue: pseudocoelomate •Body cavity lined entirely by mesoderm-derived tissue: coelomate

During embryological development, the anus forms before the mouth in _____.

humans

Acoelomates

lack an internal body cavity

endoderm

lining of digestive tract or gut

mesoderm

muscles and most other organs between digestive tract and outer covering

Both Nematodes and Arthropods

must molt in order to increase in size possess an external covering, or cuticle have a reduced coelom and an open circulatory system. Arthropods have segmented bodies that enable specialization of body structures such as appendages

Arthropods

named for their jointed appendages.

Animals that have a body cavity

nematode mouse clam earthworm

ectoderm

outer covering of animal

Radial Symmetrical

Jelly and hydra

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

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

evolution of animals

The Ediacaran biota was a group of early animals. Some are sponges, whereas others may be related to living cnidarians. Still others of these fossil organisms have proven difficult to classify. Read about this biota

Which of the following statements is correct?

All animals share a common ancestor.

Which of the following animals does NOT have a body cavity?

Flatworms are acoelomates, even those that are not classified as acoels

Hexapods (insects)

1. Body divided into head, thorax, and abdomen 2. Wings allow flight 3. butterfly 4. Three pairs of walking legs

The phylum Arthropoda

1. chelicerate (spiders, scorpions) 2. Myriapods (milepods and centipods) 3. Hexapods (beetles) 4. Crustacean ( insects and their relatives)

Chelicerate

1. passes clawlike feeding appendages 2. Feeding appendages 3. Archinds 4. Horseshoe crab

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

A coelom is formed from mesoderm tissue, whereas a pseudocoelom is formed from mesoderm and endoderm and is not fully lined with mesoderm. Read about body cavities. Provide FeedbackContinue Correct. Followup. A coelom is formed from mesoderm tissue, whereas a pseudocoelom is formed from mesoderm and endoderm and is not fully lined with mesoderm. Read about body cavities. End of followup.

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

Animals are ingestive heterotrophs

Earthworms are in the phylum _____.

Annelida

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

Cambrian

Grasshoppers are classified in the phylum _____.

Grasshoppers are classified in the phylum _____.

Which of the following is true of annelids?

Cutaneous respiration occurs across their skins. Polychaetes have lateral extensions, called parapodia, which provide even more surface area for cutaneous respiration

Sea stars are classified in the phylum _____.

Echinodermata

Insect diversity

Insects are the most diverse group of organisms, in terms of numbers of species, dominating terrestrial habitats. More than 30 orders of insects have been described, with the order Coleoptera being the largest. Classification is based on traits such as wings and mouthparts. All insects have a three-part body plan consisting of a head, thorax, and abdomen; three pairs of walking legs; and one or two pairs of wings. The chart below indicates defining characteristics for eight of the more than 30 orders of insects.

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?

Look for cell walls under a microscope.

Members of the phylum Mollusca _____.

Members of the phylum Mollusca are soft-bodied and are often covered by a shell.

Myriapods

Milipedes and centipedes exculively terristrial

Snails are classified in the phylum _____.

Mollusca

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

Most deuterostomes have indeterminate cleavage, meaning that each cell produced by early cleavage divisions retains the capacity to develop into a complete embryo. For example, if the cells of a sea urchin embryo are isolated at the four-cell stage, each can form a complete larva. It is the indeterminate cleavage of the human zygote that makes identical twins possible. Read about protostome and deuterostome development.

Ecdysozoa

Nematodes and arthropods

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

Neoproterozoic era

Crustacean

Primary aquatic two pairs of antennae crabs and isopods

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

Shared DNA sequences

Asymmetry

Sponge

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

Sponges are considered animals, and they lack these levels of organization

Celeoptera

Wing characteristic = hard forewings protectro membranous hindings Type of development = complete metamorphosis Examples= beettles (Hexapods)

Hemiphera

Wing characteristic= Thinck forewings (except at tips) Type of development = incomplete metamorphosis Example= true bugs

Lepidoptera

Wing characteristic= Wings have scales Type of development = complete metamorphosis Example= buttlerfies moths

Trichoptera

Wing characteristic= hairy wings Type of development = complete metamorphosis Example= cadolisfies

Diptera

Wing characteristic= hindwings reduced to stabilizers Type of development = complete metamorphosis Example= flies

Hymenoptera

Wing characteristic= membranous forewings and hindings Type of development = complete metamorphosis Example= ants, bees, wasps

Orthoptera

Wing characteristic= one pair leathery, one pair membranous Type of development = incomplete metamorphosis Example= grasshoppers, crickets

Which of the following is radially symmetrical?

a doughnut

Which phrases describe characteristics of both a true coelom and a pseudocoelom?

allows pressurized fluid to act like a skeleton in some invertebrates helps prevent internal injury by cushioning organs allows internal organs to move independently of each other and the outer body wall

Which of these characteristics is common to both snails and earthworms?

an alimentary system with two openings

Gastrulation is the process that directly forms the _____.

primary germ layers: two or three germ layers...ectoderm, mesoderm, endoderm

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

sea stars are deuterostomes

Bilateral Symmetry

snake octopus bobcat turtle

Nematodes

some are parasitic on humans. roundworms, are unsegmented pseudocoelomate worms that lack a circulatory system. Although most nematodes are free-living, some well-known nematodes, such as hookworms and pinworms, are parasitic.

Grasshoppers respire via _____.

spiracles and tracheae

Which of these statements is true of cnidarians?

such as jellies, have a nerve net

Deuterostome

triploblast. radial indeterminate cleavage because the cells in cleavage ratain their capacity to develop completely. Will result in identical twins coelom form from folded archenteron anus form from blastopore

Protostome

triploblast. spiral determinate cleavage coelom form when solid mass of mesoderm split Mouth form from blastopore

Which of these is a characteristic of sea stars?

tube feet