Which of the following accurately reflects the beliefs on earth's early history?
a. scientists believe that dna may have existed before rna.
b. scientists believe the early atmosphere lacked the oxygen necessary to support modern human life.
c. scientists believe that microspheres nearly prevented the development of early life.
d. scientists believe oxygen was plentiful in the early atmosphere.

the correct answer is: d. the saltine and pretzel are made of flour, yeast, and baking soda, and salt. the pecan contains no flour but it does contain fats. the pecan is a nut that can be consumed as a healthy snack. first of all, pecans are a source of fat (monounsaturated fat), but they provide less fat than some other nuts. pecans are a rich source of dietary fiber, manganese magnesium, phosphorus, thiamin, vitamin e…

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.