Pandemic viruses emerge as a result of a process called "antigenic shift," which causes an abrupt or sudden, major change in influenza a viruses. as billions of viruses replicate, mutations can cause variation in infectivity. these changes are caused by

In sexual reproducing animals once fertilization of the egg takes place, the exists as a single cell until cell division begins. a) egg b) larva c) sperm d) zygote

Imagine that certain laws of physics could be ignored and you were able to travel vast distances in moments. now imagine that you traveled to an earth-like planet located light-years away that is known to support life. think about what you’ve learned in this unit and make an argument for what you think would be the dominant type of life form on this planet. consider whether a notochord is required for an organism to manipulate its environment and become a dominant creature.

How is the carbon cycle related to global warming ?