Crystals most often form in igneous and metamorphic rocks. According to the rock cycle, which processes and features do these rocks share that likely promote the formation of crystals?

Which best describes the digestive system of arthropods? a incomplete, two openings b complete, one opening c two-way, one opening d one-way, two openings

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. what should be the frequency of the recessive allele in this population?