Answer:
A biotic factor is a living organism that shapes its environment. In a freshwater ecosystem, examples might include aquatic plants, fish, amphibians, and algae. Biotic and abiotic factors work together to create a unique ecosystem.
Answer:
21 chromosomes
Explanation:
Meiosis is a type of cell division that produces 4 haploid daughter cells (i.e., gametes) from a single diploid cell. This parental cell undergo one (1) cycle of DNA replication and two (2) cell divisions, thereby, in the case of the Norway rats that have 42 chromosomes, the final number will be 21 (21 x 2= 42)
The answer is Charles Darwin. He was the first to theorize evolution from a common ancestor.
