21. on first attachment is secondary succession
22. is the degree of variation of life....
genetic, species or ecosystem within a specific area, system or planet
23. the last one is wrong = )
Answer: The question is not complete as options are not complete , the remain part are;
A. 3.7 years, photosynthetic bacteria.
B. 3.7 years cyanobacteria.
The correct option is
3.7 billion years old, cyanobacteria and stromatolite.
Explanation:
This is because cyanobacteria is the oldest fossil to exist and they have been in existence for about 3. 7 billion years. These cyanobacteria photosynthesized because they have thread like chlorophyll filament, they produce food through the process of photosynthesis which is needed for their survival and they release oxygen as bye product.
Sorry but I can’t help you right now but later I’ll try
Answer:
Most scientists, including Darwin, thought each species was specially created by God in its present form and did not change over time.
Explanation:
