What part of an animal cell produces energy?

If a set of instructions that determines all of the charactersitics of an organism is comparedto a book,and a chromosme is compared to chaper in the book,then what might be compared to a paragraph in the book?

The body is protected against harmful flu viruses by

Heyme with this one ❤ ☺❤ name the part of the cell concerned with the transmission of hereditary characters from parents to offspring. "i will mark brainlist "