What is guttation and i need a good definition

Which system revise and send electrical signals throughout the body

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.

If jane has the blood type ab and marries john who has type o blood what are the possible phenotypes of their first kid?