31. Invertebrates

Lophotrochozoans

2 1 Lophotrochozoans Introduction

No. Flatworms do not have an anus, a coelom, or segmentation.

No. One of the phyla listed matches the description.

Some people use these animals for bait when fishing.

Which of the following phyla contains animals that are lophotrochozoans with a mouth, anus, and true coelom?

Brachiopoda is a phylum within the Lophotrochozoa. Even though they are not closely related to bivalve mollusks (such as clams or mussels), brachiopods look and act like bivalve mollusks. Specifically, brachiopods suspension feed, secrete calcium carbonate shells with two valves that hinge together in some species, and attach to rocks or other hard surfaces on the ocean floor. How is it possible for brachiopods and bivalves to be so similar if they did not share a recent common ancestor?

include leeches, earthworms, and flatworms

No. Leeches and earthworms are annelids, but flatworms are platyhelminths.

have characteristically long bodies with external, but not internal, segmentation

No. Annelids are segmented both externally and internally.

use their pseudocoeloms as hydrostatic skeletons

No. Annelids have true coeloms, not pseudocoeloms.

have a mouth that is separate from the anus

Earthworms are annelids.

Annelids __________.

Phylum Annelida

Compare the structure of a planarian (a flatworm) and an earthworm with regard to the following: digestive tract, body cavity, and segmentation.

UD III - Lophotrochozoa I | BIALIGY.com

each individual fertilizes its own eggs with its own sperm (in self-fertilization)

No. Earthworms do not fertilize their own eggs.

fertilization takes place during copulation between males and females

reproduction is by parthenogenesis, with no male participation

No. Earthworms are hermaphrodites that cross-fertilize.

hermaphroditic individuals exchange sperm

Earthworms are hermaphrodites.

During typical earthworm reproduction, __________.

No. Sea urchins are not lophotrochozoans.

No. Although tapeworms are lophotrochozoans, they do not have a lophophore.

No. Although cephalopods are lophotrochozoans, they do not have a lophophore.

A lophophore is a crown of ciliated tentacles that function in feeding.

Which of the following are lophotrochozoans that have a lophophore?

Phylum Annelida Characteristics

Annelids

What is a lophophore?
a. a specialized filter-feeding structure
b. the single opening in species with a blind gut
c. a distinctive type of larva with a band of cilia
d. a synapomorphy that defines lophotrochozoans

ANNELIDA GENERAL CHARECTER

Lophotrochozoa- Acoelomorpha

What Are Molluscs? | JONATHAN BIRD'S BLUE WORLD

A land snail, a clam, and an octopus all share
a. a mantle.
b. a radula.
c. gills.
d. distinct cephalization.

The amazing diversity of mollusks

Unit 14 - Annelids, Mollusks, and Arthropods

2 3 Lophotrochozoans   Rotifera and Ectoprocta

their larval stage of development looks completely different from the adult stage

No. This describes complete metamorphosis, which occurs in many insect species.

No. This refers to molting, which occurs several times during the lives of most arthropods.

each individual functions as both male and female in sexual reproduction by producing sperm and eggs

No. This is true of hermaphrodites and does not describe parthenogenesis.

during development of adult forms, some of the organs that were bilateral are reduced in size or are lost on one side of the body

No. This is called torsion, and it is a characteristic of gastropods.

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

Humans never use parthenogenesis.

Some species of rotifers undergo parthenogenesis, which means that __________.

All About Mollusks

Short Video: Earthworm locomotion

No. Tapeworms do not have a digestive system.

No. Tapeworms do not have a circulatory system.

No. The scolex plays a role in attachment.

This is how we get more tapeworms!

The proglottids of a tapeworm contain an elaborate __________ system.

No. Leeches have a more complex structure than cnidarians, including an anus and coelom.

No. Leeches are not flatworms. Moreover, flatworms are in the clade Lophotrochozoa.

No. Leeches are not arthropods. In addition, arthropods are in the clade Ecdysozoa.

Leeches are in the same phylum as earthworms.

Leeches are members of the phylum __________ in the clade of bilaterally symmetric animals called __________.

that have a mantle that produces an external shell

No. The cephalopod mantle covers the visceral mass, but the chambered nautilus is the only living cephalopod with an external shell.

No. Molluscs typically reproduce sexually.

No. Although chitons have segmented dorsal plates, molluscs do not have a clearly segmented body.

No. In cephalopods the sexes are separate.

Humans have this same characteristic.

Cephalopods are the only molluscs __________.

No. Only some platyhelminths (found in the clade called Rhabditophora) are parasitic.

No. Catenulids are freshwater free-living flatworms.

No. Not all rhabditophorans are parasites, although more than half of the species are parasitic.

No. Only one of the choices is completely parasitic.

Humans can be infected by a variety of parasitic flatworms.

Which of the following groups of worms is/are completely parasitic?

Mollusca | Gastropods-Bivalves-Cephlapods |

No. The bass is a chordate, not a mollusc.

No. Tapeworms are platyhelminths, not annelids.

No. Corals are cnidarians, not echinoderms.

No. Neither of these is an annelid; the snail is a mollusc, and the coral is a cnidarian.

Both of these animals have a muscular foot.

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

Tapeworms are very flat worms.

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

Mollusca (Part 1): Characteristics and Classes of Mollusks- Invertebrate Paleontology | GEO GIRL

Mollusks

No. Chelicerates are arthropods that do not have tentacles modified from a foot.

No. This is the correct phylum but the wrong clade.

The organism is similar to known molluscs.

An active marine predator is found possessing these characteristics: a series of tentacles (modified from the foot), a highly developed nervous system, and elaborate eyes. To which of the following clades does this organism most likely belong?

Phylum Annelida Part 1

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