31. Invertebrates

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 __________.

Cephalopods are the only 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?

Which of the following are lophotrochozoans that have a lophophore?

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

During typical earthworm reproduction, __________.

Annelids __________.

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

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

The proglottids of a tapeworm contain an elaborate __________ system.

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

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

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

The genes for the traits that Mendel worked with are either all located on different chromosomes or behave as if they were. How did this help Mendel recognize the principle of independent assortment? a. Otherwise, his dihybrid crosses would not have produced a 9 : 3 : 3 : 1 ratio of F2 phenotypes. b. The occurrence of individuals with unexpected phenotypes led him to the discovery of recombination. c. It led him to the realization that the behavior of chromosomes during meiosis explained his results. d. It meant that the alleles involved were either dominant or recessive, which gave 3 : 1 ratios in the F1 generation.

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

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?

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?

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