Chapter 33

Sponges feed by _________

filtering small particles from water

Which of the following is true about the phylum Cnidaria?

The bodies of its members are organized around a gastrovascular cavity.

The ________ is the middle matter of a sponge and is composed of a _______

mesohyl; gelatinous matrix The body of a sponge consists of two layers of cells separated by a gelatinous region called the mesohyl. Because both cell layers are in contact with water, processes such as gas exchange and waste removal occur by diffusion across the membranes of these cells.

Animal species that are threatened by extinction are primarily in the phylum _______

Mollusca

Evolutionary adaptations used by plants and animals for maximizing surface area include all of the following except ________

ballooning when a cell or organism grows without changing its shape, its volume increases more rapidly than its surface area. As a result, there is proportionately less surface area available to support chemical activity. The challenge posed by the relationship between surface area and volume occurs in diverse contexts and organisms, but the evolutionary adaptations that meet this challenge are similar. Structures that maximize surface area through flattening, folding, branching, and producing projections have an essential role in biological systems.

During typical earthworm reproduction ________

hermaphroditic individuals exchange sperm

hermaphroditic

In biology, a hermaphrodite is an organism that has complete or partial reproductive organs and produces gametes normally associated with both male and female sexes.

Some species of rotifers undergo parthenogenesis, which means that _________

the species consists of only females that produce more females from unfertilized eggs

Through what means do coral animals capture their food?

Tentacles that trap food particles Coral animals, like all cnidarians, have tentacles armed with batteries of stinging cells called cnidocytes. They use those tentacles to capture prey and push food into the gastrovascular cavity.

Invertebrate deuterstomes that are bilaterally symmetrical as juveniles but have radial symmetry as adults are called ________

echinoderms Sea stars (commonly called starfish) and most other groups of echinoderms (from the Greek echin, spiny; derma, skin) are slow-moving or sessile marine animals. A thin epidermis covers an endoskeleton of hard, calcareous plates.

Stages in the complete metamorphosis of arthropods include all of the following except the ________ stage.

nymph Many insects undergo metamorphosis during their development. In the incomplete metamorphosis of grasshoppers and some other insect groups, the young (called nymphs) resemble adults but are smaller, have different body proportions, and lack wings. The nymph undergoes a series of molts, each time looking more like an adult. With the final molt, the insect reaches full size, acquires wings, and becomes sexually mature.

In most insects, gas exchange is accomplished by _________

a tracheal system

Which of the following is/are true about polychaete worms?

They typically live in a marine environment.

The choanocyte of a sponge and the nematocyst of a cnidarian both function in ________

obtaining food

_________ are characteristic of jellies

Cnidocytes Cnidarians such as jellies are predators that often use tentacles arranged in a ring around their mouth to capture prey and push the food into their gastrovascular cavity, where digestion begins. Enzymes are secreted into the cavity, thus breaking down the prey into a nutrient-rich broth. Cells lining the cavity then absorb these nutrients and complete the digestive process; any undigested remains are expelled through the cnidarian’s mouth/anus. The tentacles are armed with batteries of cnidocytes, which are cells unique to cnidarians that function in defense and prey capture. Cnidocytes contain cnidae (from the Greek cnide, "nettle"), capsule-like organelles that are capable of exploding outward and that give phylum Cnidaria its name. Specialized cnidae called nematocysts contain a stinging thread that can penetrate the body wall of the cnidarian’s prey. Other kinds of cnidae have long threads that stick to or entangle small prey that bump into the cnidarian’s tentacles.

The two phyla that have characteristic U-shaped alimentary canals and a crown of ciliated tentacles are the ________ and the _______

Ectoprocta; Brachiopoda

Ectoprocta

Bryozoa, are a phylum of aquatic invertebrate animals.

Brachiopods

a group of lophotrochozoan animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs

lophophore

a crown of ciliated tentacles around their mouth. As the cilia draw water toward the mouth, the tentacles trap suspended food particles.

The proglottids of a tapeworm contain an elaborate __________ system

reproductive The proglottids of a tapeworm contain an elaborate reproductive system. Posterior to the head, or scolex, is a long ribbon of units called proglottids, which are little more than sacs of sex organs.

Some digestion in sponges takes place in the ________

amoebocytes Amoebocytes digest the food that sponges pick up from water and from choanocytes.

In arthropods, molting is necessary because _________

the chitinous exoskeleton cannot grow

chitinous exoskeleton

A tough, semitransparent substance that is the main component of the exoskeletons of arthropods, such as the shells of crustaceans and the outer coverings of insects. Chitin is also found in the cell walls of certain fungi and algae.

In the phylum Cnidaria, jellies are members of the ________ clade and corals are members of the ________ clade

scyphozoan; anthozoan

scyphozoan

are an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish

anthozoan

a member of a large class of marine coelenterates (the Anthozoa), such as a sea anemone or coral

Characteristic of the clade Lophotrochozoa are features such as a lophophore, which is a(n) _________, and a trochophore, which is a(n) ________

crown of ciliated tentacles for feeding; larval stage

The sponge cell type that is ________ and can become other sponge cell types is the ________

totipotent; amoebocyte

Tapeworms are highly specialized worms that make their living as endoparasites. To which of the following phyla do the tapeworms belong?

phylum Platyhelminthes

Invertebrate deuterstomes that are bilaterally symmetrical as juveniles but have radial symmetry as adults are called _________.

echinoderms

_________, account for ________ of all known animal species

Invertebrates, animals without a backbone; 95%

Annelids _________

have a mouth that is separate from the anus

Cephalopods are the only molluscs ________

with a closed circulatory system

Cephalopod

any member of the molluscan class Cephalopoda such as a squid, octopus or nautilus. These exclusively marine animals are characterized by bilateral body symmetry,

The three main body parts of the phylum Mollusca are a __________

muscular foot, a visceral mass, and a mantle

________ are characteristic of jellies

Cnidocytes

In most insects, gas exchange is accomplished by _________

a tracheal system

A major characteristic of arthropods is ________

a chitinous exoskeleton

Some digestion in sponges takes place in the ________

amoebocytes

amoebocytes

a mobile cell (moving like an amoeba) in the body of invertebrates including echinoderms, molluscs, tunicates, sponges and some chelicerates. They move by pseudopodia.

pseudopodia

a temporary protrusion of the surface of an amoeboid cell for movement and feeding.

Characteristic of the clade Lophotrochozoa are features such as a lophophore, which is a(n) _________, and a trochophore, which is a(n) ________

crown of ciliated tentacles for feeding; larval stage

_______ is a compound produced by sponges that can kill ________

Cribrostatin; cancer cells and drug-resistant strains of Streptococcus

Some species of rotifers undergo parthenogenesis, which means that _________

the species consists of only females that produce more females from unfertilized eggs

The two lineages of the phylum Platyhelminthes are the ________ and the ________

Catenulida; Rhabditophora

Catenulida

an order of flatworms in the classical classification, or a class of flatworms in a phylogenetic approach. They are relatively small free-living flatworms, inhabiting freshwater and marine environments

Rhabditophora

Rhabditophora is a class of flatworms. It includes all parasitic flatworms and most free-living species that were previously grouped in the now obsolete class Turbellaria.