Cells of the nervous system which supports the neurons by producing myelin sheaths and attaching neurons to blood vessels are called:

What type of limiting factor affects a large population more then it affects a small population

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.

What is a sex-linked genetic disorder that disrupts the blood's ability to clot? a.achondroplasia b.huntington's disease c.hemophilia d.albinism