What can explain why all organisms do not defend themselves against all natural enemies? a) not all defenses are effective against all natural enemies. b) not all organisms are attacked by the same natural enemies. c) defenses are costly to produce. d) all of the choices are correct.

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.