Which statement best explains why invertebrates regenerate lost tissue more readily than most vertebrates do?
A. Invertebrate animals have more undifferentiated cells than vertebrate animals have.
B. Invertebrate animals reproduce asexually, but vertebrate animals reproduce sexually.
C. Invertebrates contain specialized cells that produce the hormones necessary for this process.
D. Invertebrate cells exhibit a higher degree of uncontrolled cell division than vertebrate cells do.
Invertebrates, animals without a backbone such as an earthworm, are simpler than vertebrates such as a human. Therefore, their cells are not as complex and they may be able to regenerate or grow lost body parts easier than a more complex animal.