When used appropriately, antibiotic treatment can effectively reduce bacteria populations and help fight infections. However, antibiotic treatments can have unintended effects. What is one concern when using antibiotics?

#Question id: 4967

#Unit 11. Evolution and Behavior

Recent evidence indicates that the first major diversification of multicellular eukaryotes may have coincided in time with the

#Question id: 4968

#Unit 11. Evolution and Behavior

Which of these observations fails to support the endosymbiotic theory for the origin of eukaryotic cells?

#Question id: 4969

#Unit 11. Evolution and Behavior

The snowball Earth hypothesis provides a possible explanation for the

#Question id: 4970

#Unit 11. Evolution and Behavior

If two continental land masses converge and are united, then the collision should cause

#Question id: 4971

#Unit 11. Evolution and Behavior

On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords?

#Question id: 4972

#Unit 11. Evolution and Behavior

Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. It apparently lived in arid regions, and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous. The dicynodonts had two large tusks, extending down from their upper jaws; the tusks were not used for food gathering, and in some species were limited to males. Food was gathered using an otherwise toothless beak. Judging from the fossil record, these pig-sized organisms were the most common mammal-like reptiles of the Permian. Anatomically, what was true of Lystrosaurus?