Problem:

Question 1: What is a 'stromatolites' and what might be a possible relationship between their formation in early earth and atmospheric changes? What is the significance of this atmospheric change?

Question 2: Describe the three modes that prokaryotes can 'obtain' new genes. Be sure to identify similarities and differences between the three modes. How does the concept of new gene introduction change the view that prokaryotes are asexual species?

Question 3: which statement below best explains why the free O2 in the atmosphere, may have led to a greater diversity of eukaryotic forms?

A. More O2 would have increased metabolism and ATP production which may have increased growth and reproductive rates and therefore species evolution

B. More O2 would have balanced against greater concentrations of toxic gases thus increasing the survivorship of species and therefore species evolution

C. More O2 would have led to the development of complex polymers which would have given rise to more complex forms of life and species evolution

Question4: Which statement below best describes why the protists are considered a group at an evolutionary 'crossroads'?

A. Protistans represent a diverse group that provided the building blocks for the fungi, plants and animals

B. Protistans represent a mix of prokaryotic and eukaryotic life forms

C. Protistans have the ability to rapidly exchange genetic information between different species thus blurring the lines between distinct evolutionary units of life

Please suggest the correct answer of these questions.