A. Population
B. Communities
C. Species
D. Organs
A. Cell
B. Organetia
C. Tissue
D. Organ
A. Tissue
B. Organella
C. Species
D. Organ system
A. Biotechnology
B. Parasitology
C. Human biology
D. Social biology
A. Human biology
B. Social biology
C. Parasitology
D. Environmental biology
A. Social biology
B. Human biology
C. Environmental biology
D. Molecular biology
A. Microbiology
B. Parasitology
C. Molecular biology
D. Environmental biology
A. Freshwater biology
B. Marine biology
C. Molecular biology
D. Parasitology
A. Parasitology
B. Microbiology
C. Fresh water biology
D. Marino biology
A. Environmental biology
B. Molecular biology
C. Biotechnology
D. Social biology