approximately 2.2 billion years ago which gas was first added in large amounts to earth atmosphere from life forms that evolved in the oceans

Which of the following characteristics is similar between the sympathetic and parasympathetic branches for most neurons? a. Receptor type on the target tissues b. Site of origin of the nerves c.

Part of the dermal tissue that is made of hard, dead, cork cells is the

What does it mean when a biologist uses the term crossing-over? why is crossing over a good thing?

Bastille Day is celebrated in A) France B) The Netherlands C) Luxembourg D) Belgium

What level of organization that is a group of tissues working together?

Scientists were able to determine the age of the earth from rock samples that were analyzed. What technique was used to do this

How does the human heart organization relate to cells? To organ systems?

Why could a diet low in carbohydrates be dangerous?

What is a pathogen free environment

which object would take the most force to hold up in the air? A. a bus B. a chair C. a balloon D. a nail