Final answer:
Complexity in biology is related to genetics, replication, metabolism, and biochemistry, all of which contribute to the intricate processes and systems in living organisms. Option number 4 is correct.
Step-by-step explanation:
The topic of complexity in biology primarily relates to the intricate systems and processes that define living organisms. When discussing complexity, subjects such as genetics, replication, metabolism, and biochemistry are all highly relevant. Genetics involves the study of genes, heredity, and the variation of organisms, which certainly contributes to the biological complexity. Replication refers to the process of copying DNA in a cell before it divides, ensuring genetic information is passed on accurately. This process adds to the complexity as it needs to be precise to maintain genetic integrity.
Metabolism encompasses all the biochemical reactions that happen within organisms, including catabolic and anabolic reactions that define how organisms obtain and use energy. Finally, biochemistry is the study of the chemical processes within and related to living organisms, including understanding the genetic code and how DNA and proteins dictate the function of cells.