Question: How did the evolution of photosynthetic life alter Earth’s the atmosphere? A )Oxygen began to accumulate in the atmosphere as it was released by organisms
B) Hydrogen moved to the top of the atmosphere and most of it escaped into space
C) Ammonia molecules were broken down into nitrogen and hydrogen due to
lightning strikes
D) Carbon dioxide began to dissolve into the ocean at a faster rate

What's the waste product of electrons and pyruvate combining in fermentation?  

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?