Climate covers smaller or larger areas than weather

Many kangaroo rats live in the sonoran desert of the southwestern united states. they have a variety of adaptations for living in the desert. under which circumstance would the kangaroo rats of the sonoran desert be most likely to develop new adaptations by natural selection?

Transmission electron microscope are best for viewing a) microorganisms in pond water b) internal organs of a mouse c)internal structures of a cell d) surface features of a specimen

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