Write the letter in the space provided of the choice that best completes the statement.

14. A species is defined as a group of similar-looking organisms that
a. undergo similar developmental changes
b. can interbreed
c. can interbreed and produce fertile offspring
d. reproduce in the same way

15. Every organism begins life as a(n)
a. embryo
b. single cell
c. nucleus
d. fertilized egg

16. A corn plant producing ears of corn is an example of
a. growth
b. reproduction
c. development
d. all of these

17. If members of a species fail to reproduce successfully, the species
a. will eventually become extinct
b. will evolve into a new species
c. will not develop normally
d. will remain unchanged