Which lineage is now extinct, but appears in the fossil record from the Ordovician period through to the Devonian period?
a. conodonts
b. acanthodians
c. ostracoderms
d. placoderms
Answer: c. ostracoderms
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Genes from different organisms with similar sequences or open reading frames (ORFs) are called ________.
Fill in the blank(s) with the appropriate word(s).
What is the chordate feature still present in the human adult?
a. pharyngeal gill slits b. nerve cord c. notochord d. tail e. nerve cord and notochord
An atom with more protons than electrons is called a(n) __________. Fill in the blank(s) with the appropriate word(s)
Select the true statements describing why cladistics may not always be the best method for reconstructing phylogenies based on data from the DNA genome.
A. The number of character states for DNA is large. B. The rate of evolution of the DNA genome is rapid. C. The assumptions of the principle of parsimony are not always met. D. Homoplasy often dominates the data sets.