Mastering Biology Chapter 27

Why doesn't Dr. Logan feel the bed bug feeding on him?

What makes bed bugs different than most other blood-feeding parasites?

Many blood-feeding parasites carry diseases but bed bugs do not. What is the most logical explanation for this?

Why do we often get an itchy red bump after being bitten by a bed bug?

Bed bugs probably evolved from bat bugs. Which statement best describes how this likely happened?

What does the bed bug illustrate in regards to evolution?

Some scientists are conducting research on the "saliva" of bed bugs. Which of the following is the most logical medical benefit from this research?

Nematodes and arthropods are the largest ecdysozoan phyla. Which of the following statements are true?

Whatever its ultimate cause(s), the Cambrian explosion is a prime example of

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. Only animals reproduce by sexual means. 5. Animals are thought to have evolved from flagellated protists similar to modern choanoflagellates.

Which of the following was probably the LEAST important factor in bringing about the Cambrian explosion?

What is the significance of the evolution of Hox gene clusters during vertebrate evolution?

The members of which clade in the phylum Cnidaria occur only as polyps?

Trichoplax adhaerens (Tp) is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 μm high, are irregularly shaped, and consist of a total of about 2,000 cells, which are diploid (2n = 12). There are four types of cells, none of which is a nerve or muscle cell, and none of which has a cell wall. They move using cilia, and any "edge" can lead. Tp feeds on marine microbes, mostly unicellular green algae, by crawling atop the algae and trapping it between its ventral surface and the substrate. Enzymes are then secreted onto the algae, and the resulting nutrients are absorbed. Tp sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage. Tp's body symmetry seems to be most like that of

Which of the following statements about deuterostomes is false?

Which structure is not an innovation that occurred during vertebrate diversification?

True or false? An organism that is radially symmetric has many well-developed head regions.

Which characteristic distinguishes echinoderms from the other two deuterostome lineages?

Which of the following statements about vertebrates is true?

Which characteristics define a chordate?

Which structure can be used for feeding and gas exchange?

Fossil evidence indicates that the following events occurred in what sequence, from earliest to most recent? 1. Protostomes invade terrestrial environments. 2. Cambrian explosion occurs. 3. Deuterostomes invade terrestrial environments. 4. Vertebrates become top predators in the seas.

In the figure given below, the clade Deuterostomia is most closely related to which two main clades?

In terms of food capture, which sponge cell is most similar to the cnidocyte of a cnidarian?

Which of the following is a point of conflict between the phylogenetic analyses presented in these two figures?

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition by

Animal tissues develop from embryonic germ layers. Triploblastic animals have three germ layers (ectoderm, mesoderm, and endoderm) and three basic body plans related to body cavities (acoelomate, pseudocoelomate, and coelomate).

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships?

Using similarities in body symmetry and other anatomical features to assign an organism to a clade involves 1. cladistics based on body plan. 2. molecular-based phylogeny. 3. morphology-based phylogeny.

Sponges are most accurately described as

What do all craniates have that earlier chordates did not have?

Which of the following animal groups is entirely aquatic?

Which of the following is (are) unique to animals?

Which of the following functions as both a mouth and an anus in members of the phylum Cnidaria?

Select the correct statement(s) describing nematodes.

A trend first observed in the evolution of the earliest tetrapods was