What is the source of energy in most ecosystems

Which best explains why there are 64 possible codons in the genetic code and only 20 amino acids that make protiens of living organisms on earth

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.

14) whenever diploid populations are in hardy-weinberg equilibrium at a particular locus a) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change. b) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency. c) this means that, at this locus, two alleles are present in equal proportions. d) the population itself is not evolving, but individuals within the population may be evolving.