Of rocky planet which planets are mostly made of atmosphere

What are antigens and antibodies? how are they involved in the body’s response to incompatible blood?

Is dna the same in every cell in the human body explain your answer

1. in what ways have non-native species been beneficial? 2. what are some of the hypotheses for the collapse of honeybee colonies? 3. distinguish between regional and functional extinction. 4. why is it difficult to measure background extinction rates? 5. what three factors are most important in causing extinction rates to climb?