Which type of fossil appears as a “black painting” on a rock?

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.

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.

Did the vinegar diffuse all the way to the center of any of the cubes? if so, which ones? what does this tell you about surface area-to-volume ratio and the diffusion rate?