Which of these is an abiotic change to an environment? a. a species goes extinct b. a fire destroys the topsoil in a forest c. a tree falls down d. a new species is introduced

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

Which of the following statements is accurate about evolution? question 10 options: natural selection only eliminates odd individuals. evolution means that a population never has changes in its genetic frequencies. mutations are always harmful. evolution means that a population undergoes changes in its gene frequencies over time.

Aragonite shells of clams, snails, or scleractinian corals may be preserved unaltered in cenozoic deposits, but they are generally dissolved or recrystallized in older deposits. true or false