Sperm cell, red blood cell, nerve cell, muscle cell, ovum cell :)
They are evidence that all came from a common ancestor and that life changed over time for all these organisms to exist.
When several monomers join together they form a polymer.
The answer is A. And if you are from connections Academy 7th grade science it's
1. A
2. C
3. B
4. D
5. A
They both involve topics related to the natural world, and are both based on empirical evidence. <span />