Agalaxy cluster is a. another name for a star cluster. b. a group of stars that cluster just outside a galaxy. c. another name for the milky way. d. a group of galaxies bound together by gravity.

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

Gregor mendel is best known for his work with pea plants and for uncover many of the mysteries of genetics. one of his major findings stated that there were specific, physical units of inheritance that are transmitted during reproduction. what is the the name given to these units of inheritance which can be found on chromosomes? a) centromeres b) cytoplasm c) genes d) nucleotides

Why are current extinctions of concern to enviromentalists?