What can be detected by using SIM medium? (Check all that apply.)

The last common ancestor of all bilaterians is thought to have had four Hox genes. Most extant cnidarians have two Hox genes, except Nematostella (of ?-catenin fame), which has three Hox genes. On the basis of these observations, some have proposed that the ancestral cnidarians were originally bilateral and, in stages, lost Hox genes from their genomes. If true, this would mean that _____.

A) the Radiata should be a true clade B) the radial symmetry of extant cnidarians is secondarily derived, rather than being an ancestral trait C) Hox genes play little actual role in coding for an animal's "body plan" D) the Cnidaria may someday replace porifera as the basal bilaterians B) the radial symmetry of extant cnidarians is secondarily derived, rather than being an ancestral

During long-term stress, cortisol levels can remain high. What are some of the problems associated with this?

What will be an ideal response?

Which of the following is the BEST description of evolution as currently understood by modern biologists?

a) Evolution is goal directed. b) Evolution is influenced by the differential survival and reproduction of phenotypes. c) Evolution includes the results of selection for acquired characteristics. d) Evolution is synonymous with the process of mutation. e) Evolution is synonymous with the process of gene flow.

Which of the following is not an example of goods and services provided by the environment?

A. Raw materials for goods we use every day, such as wood B. The control of erosion C. Water treatment D. All of the above are examples of goods and services provided by the environment.