Plz help with my science work

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

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.

Asap indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. alleles: a=agouti, c=chinchilla, a=albino, a is dominant over c and a, c is dominant over a agouti x chinchilla a) 1/2 chinchilla, 1/2 agouti b) 3/4 chinchilla, 1/4 agouti c) all agouti