Exam 30: An Introduction to Animals

From the information provided in the accompanying table, how would you classify the feeding strategy of organism C?

To reproduce, many plants produce seeds-structures containing embryonic offspring along with nutrients inside a tough case. These offspring develop after being released by the parent plant. To which animal reproductive strategy is seed production most comparable?

A: Morphological phylogeny. B: Molecular phylogeny. In the traditional morphological phylogeny (A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (B), Platyhelminthes is depicted as a lophotrochozoan phylum. What probably led to this change?

-Dll is a gene known to direct limb development in the fruit fly. Researchers studying this gene have found that it is also expressed in developing appendages in animals from many other phyla, supporting the hypothesis that all animal appendages may be homologous. However, suppose researchers looking at Dll activity had instead found the results shown in the preceding table. These results suggest instead that ________.

Among protostomes, which morphological trait has shown the most variation?

Use the following information and figure to answer the question below. In a review paper published in 2000, Adoutte et al. examined some animal phylogenies generated by comparing the ribosomal RNA (rRNA) of animals from many different phyla. They then integrated these independently created phylogenies into one phylogeny that best fit all the data. The figure below compares a traditional phylogeny based on morphological characteristics (A) to the new molecular-based phylogeny described by Adoutte et al. (B). Note that platyhelminthes, nemerteans, and entoprocts, which do not have coeloms and are classified as acoelomates in the morphological phylogeny, are reclassified as lophotrochozoans in the molecular phylogeny. Similarly, groups classified as pseudocoelomates in the morphological phylogeny are reclassified as either lophotrochozoans or ecdysozoans in the molecular phylogeny; other lophotrochozoans and ecdysozoans have coeloms. Copyright 2000 National Academy of Sciences, U.S.A. (A. Adoutte, G. Balavoine, N. Lartillot, O. Lespinet, B. Prud'homme, and R. de Rosa. 2000. The new animal phylogeny. Proceedings of the National Academy of Sciences USA 97(9):4453-56.) What does this reclassification based on molecular data imply about the evolution of acoelomates, pseudocoelomates, and coelomates?

You find a new species of worm and want to classify it. Which of the following lines of evidence would allow you to classify the worm as a nematode and not an annelid?

Choanoflagellates ________.

How many of the following are characteristics of at least some members of the phylum Cnidaria? 1) a gastrovascular cavity 2) a polyp stage 3) a medusa stage 4) cnidocytes 5) a pseudocoelom

Comb jellies may not be the most familiar animal to you, but they are critical in the food chain because they make up a significant portion of the planktonic biomass. Their feeding strategy is predatory and involves adhesives or mucus on their tentacles or other body parts. What feeding tactic do these animals use?

At which developmental stage should one be able to first distinguish a diploblastic embryo from a triploblastic embryo?

The central nervous system is lacking in animals that have ________.

Sponges ________.

What unique characteristic do all deuterostomes have in common?

Suppose you came across a novel organism you suspected belonged to one of the following animal phyla: Porifera, Cnidaria, Ctenophora, or Acoela. Which of the following characteristics would NOT be helpful in placing the organism into the correct phylum?

Which of the following is most likely to be aquatic?

Which of the following statements concerning animal taxonomy is (are) TRUE? 1) Animals are more closely related to plants than to fungi. 2) All animal clades based on body plan have been found to be incorrect. 3) Kingdom Animalia is monophyletic. 4) Animals only reproduce sexually. 5) Animals are thought to have evolved from flagellated protists similar to modern choanoflagellates.

Due to its unusual habitat (inside the digestive tracts of other animals), the tapeworm lacks a ________.

Most fish deposit fertilized eggs, but some sharks keep the fertilized egg inside the female until she gives birth to a relatively well-developed pup. These sharks would thus be characterized as ________.

Sponges are most accurately described as ________.