Answer:
They are called the building blocks of an organism because all living things are made up of billions of cells that can reproduce, build and change that's why it is called the building blocks of all living things.
Explanation:
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
Answer:
d. cells
cardiac tissue are made up of cells.
It would be my clown fish on the Shelly of mapel fish