Question

1. What taxonomic classes of vertebrates are considered descendants of their tetrapod ancestors?

2.What is the developmental fate of the embryonic, pharyngeal pouches as they develop in fish?

3.What type of speciation involves a new species arising from within an existing incipient population influenced by diverse habitats and niches within its geographic range

4.What term describes the relatively rapid speciation that occurs from a founder population colonizing an area that has undergone a disturbance significant enough to cause a sudden reduction in biodiversity by the extinctions of many previous species

5.When a sexually reproducing population undergoes speciation, whereby the new species use different types of social behaviors to attract mates, the speciation event is generally resulting from some type of ___________ isolation mechanism.

6.The fact that the bone structure supporting the flipper of a seal is similar in pattern to the bone structure that supports the wing of a bat is an example of _____________ (convergent or divergent) evolution?

7.What term describes a spontaneous alternation in the arrangement of nucleotides within a germ line chromosome that can result in either a structural or physiological change in future generations

8.What adjective term involving the zygote describes the reproductive isolation mechanism that results in a hybrid offspring being inviable and unable to reproduce

9.What is the chemical compound that composes the exoskeleton of the ecdysozoans

10.What organ of the mollusks secretes the shell of the gastropods?

Answer 1

1. Tetrapods are those organisms having four limbs for the locomotion on land. The classes that are the descendants of tetrapod ancestors are :

1. Amphibia. 2. Reptilia 3. Aves 4. Mammalia.

2. The pharyngeal pouches of the embryonic fish develop in to gills in the fish. They reach the ectoderm and break through it to form gill clefts which later develop gill filaments ot form gills.

3. It is parapatric speciation. This is because the organisms are in a large geographical area with different niches and environmental conditions.So, with in same geographical area they are developing in to new species.

4. It is adaptive radiation. That is because the founder group has reached the place where there are very few organisms surviving. That is why there are variety of habitats available and hence the organisms move to different habitats and adapt. This rapidly leads to speciation.