Biology Exam 3

Earthworms are in the phylum _____.

Annelida

Grasshoppers are classified in the phylum _____.

Arthropoda

While on a biological expedition, you discover a new species with the following characteristics: has an exoskeleton, exhibits bilateral symmetry, and has jointed appendages. What phylum does this newly discovered organism belong to?

Arthropoda

The _____ explosion occurred approximately 545 million years ago.

Cambrian

A sea star and a hookworm belong to the phyla _____ and _____, respectively.

Echinodermata ... Nematoda

______ are the most diverse group of arthropods.

Insects

Snails are classified in the phylum _____.

Mollusca

Roundworms are classified in the phylum _____.

Nematoda

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

Precambrian

How do sponges differ from all other animals?

Sponges lack true tissues.

Why are annelids, arthropods, and mollusks placed in the same clade?

They are protostomes.

Which of these statements is true of earthworms?

They have a digestive system with two openings.

Which of these statements is true of sponges?

They have no true tissues.

A distinguishing feature of vertebrates is the presence of _____.

a backbone

One body plan, called bilateral symmetry, represents a major branch point in animal evolution and can be described as __________.

a body plan with only one way to split it into two equal halves—right down the midline

Which of the following is associated with bilateral symmetry?

a definite "head end"

Which of the following is radially symmetrical?

a doughnut

Which of the following is an invertebrate?

a sponge

Insects, such as the grasshopper shown below, have ______.

a three-part body: head, thorax, and abdomen

What characteristic is unique to echinoderms?

a water vascular system

According to this phylogenetic tree, the animals most closely related to reptiles and mammals are _____.

amphibians

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

an alimentary system with two openings

Which of these characteristics is shared by both dogs and sea stars?

an endoskeleton

The legless, segmented body of the animal below suggests that it is a(n) ______.

annelid

Annelids __________.

are segmented worms

Members of the phylum Mollusca __________.

are soft-bodied and usually covered by a shell

According to this phylogenetic tree, annelids are most closely related to _____.

arthropods

There are more species of ______ than of any other type of animal.

arthropods

Flatworms are the simplest animals with __________.

bilateral symmetry

Which anthropoids are most closely related to humans?

chimpanzees

The arthropod skeleton is composed of ______.

chitin

What name is given to the food-trapping cells of sponges?

choanocytes

Echinoderms are _____.

deuterostomes

Sea stars and sand dollars belong to a group of spiny marine animals called _____.

echinoderms

Annelids, such as the leeches, __________, a characteristic shared by all other bilateral animals except flatworms.

exhibit a complete digestive tract

As adults, sea stars _____.

exhibit radial symmetry

Sponges feed by __________.

filtering small particles from water

The figure below shows a planarian. Bilateral symmetry, the leaflike shape, and the highly branched gastrovascular cavity all suggest that the planarian is a(n) ______.

flatworm

Consider the following list of animals: giant squid, earthworm, largemouth bass, snail, tapeworm, coral, and sea star. The two that belong to the same phylum are the __________, and their phylum is _____.

giant squid and snail ... Mollusca

Flatworms are similar to cnidarians in that both ______.

have true tissues

What does the term tetrapod mean?

having four feet

Earthworms are most closely related to _____.

leeches

The mobile stage of the cnidarian life cycle is the ______ stage.

medusa

According to this phylogenetic tree, the clade that includes echinoderms and chordates is most closely related to the clade that includes _____.

molluscs

Annelids are most closely related to ______.

molluscs

The water vascular system of a sea star functions in __________.

movement of the tube feet

A(n) ______ is an example of a mollusc that does not have a shell.

octopus

Molluscs are _____.

protostomes

What type of symmetry does this organism exhibit?

radial

Cnidarians are in the _____ clade.

radiata

Nematodes are most closely related to _____.

rotifers

A characteristic of arthropods that has allowed for their great success is the presence of ______.

specialized segments

Grasshoppers respire via _____.

spiracles and tracheae

Which of the following are found in members of the phylum Cnidaria?

stinging cells, radial symmetry

A characteristic of cnidarians is __________.

tentacles with stinging cells

In arthropods, molting is necessary because __________.

the chitinous exoskeleton cannot grow

The phrase "Cambrian explosion" refers to __________.

the rapid adaptive radiation that gave rise to most extant animal phyla

Which of these is a characteristic of sea stars?

tube feet