What organisms "fix" nitrogen, which allows plants to make amino acids?

What do geologists think happened as the last ice age ended? O A. Sea levels rose over 300 feet. B. A mass extinction occurred. C. Glaciers advanced worldwide. D. Dense forests grew for the first time.

DNA within the cell is wrapped around nucleosomes to form chromatin. When chromatin is in the form of a 30 nm fibril, how many copies of H1 and H2A histone proteins would be found in a stretch of chromatin containing 20 nucleosomes? a.

Blood is carried through the body in blood vessels. True or false?

Which of these three molecules-DNA, RNA, or proteins-most likely operated in the ancient past prior to the appearance of the other two molecules? Explain how this earliest "proto-life" chemical serves more than one function.

The one factor that a scientist changes during an experiment

You are studying the source of new virus that has recently infected humans. You suspect that the virus was transferred from other primates (they exhibit a similar infection), specifically chimpanzees, gorillas, or orangutans.

According to the diagram liverworts are

What type of compounds always contain carbon and hydrogen

What is the junction between a nerve cell and another cell called: axon, synapse, dendrite, none of the above

1. Synthesize Information How do you explain to the horse owner why this foal was born with OLWS while two previous foals were perfectly healthy? What would you tell the new parents of the baby girl about their prospects for having more children?