There are over 300 different species of fiddler crabs. In all of these species, the adult males possess an enlarged front claw. Based on this feature, biologists group these different species together in the same genus, Uca. Therefore, the large claw is
|B)||an analogous trait.|
The domestic dog, Canis familiaris, is related to wild dog species such as the gray wolf, Canis lupus. To which most exclusive category do the wolf and dog both belong?
The simplest animals, the sponges (Parazoa), lack true tissues. All other animals (Eumetazoa) have distinct tissues. The presence of true tissues is a
|A)||useful character for distinguishing amongst the eumetazoans.|
|B)||shared ancestral state.|
|C)||shared derived state.|
Originally, organisms were classified according to a two-domain system that consisted of the bacteria and the eukaryotes. Recently, a three-domain system of classification has been proposed in which domain Bacteria was divided into domain Archaea and domain Bacteria. This is because
|A)||there are so many different species of prokaryotes.|
|B)||of the large genetic differences between the archaebacteria and the bacteria.|
|C)||the archaebacteria have a nucleus like that of eukaryotes.|
|D)||the archaebacteria live in inhospitable environments, so they should be put in a different domain.|
Which of the following is the most abundant group of organisms on earth?
Biologists do not consider viruses to be alive. This is because viruses
|A)||are unable to reproduce on their own.|
|B)||do not contain genetic material.|
|C)||do not contain proteins.|
|D)||are smaller than living organisms.|
As more is learned about the molecular and genetic aspects of organisms, taxonomic groupings are changing. Which group of eukaryotes is the focus of most controversy related to their taxonomic groupings?
According to new molecular and biochemical information, should the plants still be recognized as a distinct kingdom?
|A)||Yes, the green algae are now considered to be in the kingdom Plantae.|
|B)||Yes, the green algae and the plants are now recognized to be unrelated.|
|C)||No, the plants and the green algae are now classified together in the kingdom Virdiplantae.|
|D)||No, the plants are now classified together within the Chlorophyta.|
The relationship between the annelids and the arthropods is now thought to be