Earth’s early atmosphere was a result of seismic activity. true false

True

Explanation:

Some 4.5 billion years ago, the atmosphere consists of mainly gases released due to the extreme volcanic activities taking place on earth. The predominant gases during those days were carbon dioxide, and no oxygen along with some small portions of ammonia, methane and vapor. These vapor later condensed to form water bodies of present time.  

Hence, the given statement is true.  

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

layer 3 is younger than layer 6.