Invertebrate Diversity

Question 1

All members of Metazoa share the following general characteristics: they are multicellular ____ with diverse forms that mostly lack ___ ____, employ _____ ____, and are the largest _____ on Earth (Freeman et al., 2016; Raven & Johnson, 2002).

Answer 1

heterotrophs, cell walls, active movement, consumers

Question 2

Animals are also classified into two major groups: invertebrates and vertebrates.

_______ feature animals without a true vertebral endoskeleton. When introducing invertebrates, we often start with the ones with the simplest forms (Reece et al., 2013):

Answer 2

Invertebrates

Question 3

Invertebrate animals include: (9)

Answer 3

Porifera, Cnidaria, Ctenophora, Platyhelminthes, Rotifera, Nematoda, Annelida, Mollusca, and Arthropoda.

Question 4

_______ live in aquatic and terrestrial environments, from polar to tropic regions, and from the
deepest part of the sea to the highest parts of mountains (Hickman et al., 2008).

Answer 4

Nematodes

Question 5

Nematodes are parasitic or free-living. Parasitic nematodes feed on ____ of their animal or plant hosts. Free-living (non-parasitic) nematodes feed on bacteria, yeasts, fungal hyphae, and algae. The most common example of a free-living nematode is the model organism Caenorhabditis elegans (Class Chromadorea) (Hickman et al., 2008).

Answer 5

nutrients

Question 6

Nematodes:
-number of germ layers

Answer 6

-triploblastic, 3 layers: ectoderm, mesoderm, endoderm

Question 7

______ gives rise to the animal covering, _____ gives rise to the lining of the digestive tract, and _____ gives rise to the muscles and organs between the gut and outer covering (Weedman, 2011).

Answer 7

Ectoderm, endoderm, mesoderm