How is the recombination rate important in constructing a gene map?

What would happen to the nutrients in an ecosystem if decomposers, such as bacteria, didn’t exist there?

Which organelles are labeled d, and what is one feature that distinguishes them from the other labeled organelles chloroplasts the only organelles that produce sugars from sunlight mosomes, only found in animal and bacterial cells centricles only found in animal cells mitochondra, the only energo-generating structures found in cells

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?