Which landform is an area in a Koppen E zone? A. desert

B. savannah

C. tundra

D. grassland

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

Aheterozygous normal male marries a woman with a sickle cell anemia. give the genotypes and possible phenotypes of the offspring

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons