Arelationship between two organisms where one harms the other is called

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

Crossing over is a method of (blank)?

What are antigens and antibodies? how are they involved in the body’s response to incompatible blood?