Review the images of the two biomes, the tundra and the taiga. notice that while there are about 1,700 kinds of plants there are virtually no tree species in the tundra. what are the limiting factors in preventing the immigration of tree species into the tundra. all but one can apply

a. rocky, poor soil
b. very short growing season
c. the presence of permafrost
d. winters are 6 months long

African penguins, which inhabit the coasts of southern africa, were classified as an endangered species in 2010. two significant threats to their survival are ecosystem damage from oil spills and overfishing by humans. overfishing depletes the food supply of african penguins. the best method to reduce the threat of overfishing would be to . the risk of oil spills could be reduced by increasing the use of , which should oil consumption. if an oil spill does occur, could be used to remove the oil so the ecosystem may more quickly recover.

What is the next step in the process after a substrate enters the active site of an enzyme

Interferons play a vital role in the immune system why are interferons so important?