According to the phylogeny tree, which phylum of organisms are most closely related to chordates?
cnidaria
nematoda
annelida
echinodermata
porifera
platyhelminthes mollusca
arthropoda
sponges jellyfish matworms round worms mollusk vegmented insects starfish
worms spiders
chordata
vertebrates
backbone
segmentation
endoskeleton
coelom
body cavity
bilateral symmetry
tissues
multicellularity
ancestral protist

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 a strand of dna has 35% thymine. what is the percentage of cytosine, adenine, guanine?

When a gasoline engine burns gasoline, what type of chemical reaction is occurring?