Subjects
Sections | |||
---|---|---|---|
Prokaryote Cell Structures | 24 mins | 0 completed | Learn |
Prokaryote Reproduction and Gene Exchange | 17 mins | 0 completed | Learn |
Prokaryote Metabolism and Ecology | 16 mins | 0 completed | Learn |
Prokaryote Lineages | 9 mins | 0 completed | Learn |
Oxygen concentration of 1% of 1 billion years ago increased to the present level of 21% because of photosynthetic activity of
a. fungi
b. cyanobacteria
c. plants
d. protists
e. animals
Enter your friends' email addresses to invite them:
Join thousands of students and gain free access to 23 hours of Biology videos that follow the topics your textbook covers.