Consider this northern site of primary succession following the retreat of a glacier. plant species at location b .

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex

answer: dna

because all cells have genes

answercells,tissues,organs,organ,system-organism;

levels of biological organization; organism,population,community,ecosystem,biome,biosphere,

hope this .good luck