Cyanobacteria, unusual worm like life-forms and marine organisms did not exist in precambrian time. true of false?

Consider the last statement in the prompt: "people take such environmental factors into account in their choices when deciding where to live." do all people have a choice as to where they live? what factor plays a key role in this decision and may therefore play a large role in determining quality of life?

If jane has the blood type ab and marries john who has type o blood what are the possible phenotypes of their first kid?

This is the main structural axis of the plant that supports leaves, flowers and fruits; transports fluids; stores nutrients and produces new tissue.