Why does lymph need to flow more slowly through the lymph nodes?

What statements describe a host organism?

If the coding part of an mrna molecule is 1800 nucleotides (bases) in length, this molecule will contain codons and code for a polypeptide that is amino acids long.

How is ribosomal rna useful as a molecular clock? a. a large portion of the dna ring is not vital to structure or function, allowing it to accumulate neutral mutations. b. its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. c. a slow mutation rate makes it useful for determining evolutionary relationships between ancient species. d. it is only found in select organisms, making it easier to compare relationships between species that have it.