Ichthyostega is a 370-million-year-old fossil from Greenland. Ichthyostega had digits, eyes on the top of its head, and strong, armlike bones. It also had no gills and a reduced tail—traits it had in common with Tulerpeton. Acanthostega, Eusthenopteron, and Tiktaalik all had gills and full tails. Use the abbreviations provided to draw a phylogenetic tree that includes Ichthyostega.

Read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. applying the biological species concept, the sterility of ligers reveals that a. lions are probably a subspecies of tigers b. tigers and lions are the same species c. a new species called "ligers" is forming d. tigers and lions are separate species

What are the two main phases of a cell cycle

Biology ! the conversion of inorganic carbon to organic carbon by plants during photosynthesis is known as _[blank]_. filtration immigration reabsorption primary production