Spinal cord injuries can be difficult to treat because damaged nerve cells do not regenerate. why is that ?

Which statement about dna replication is true? a. eukaryotes only have one circular chromosome that unwinds at multiple locations. b. eukaryotes can only replicate one segment of a chromosome at a time. c. prokaryotes can only replicate their single circular chromosome in the nucleus. d. prokaryotes only have one origin of replication to initiate replication.

Number and variety of living organism; includes genetic, species, and ecological types

Nucleic acids offer variability because they contain alternate forms of genes called .