A. Genes involved in the cell cycle
This is because cancer is a defect that causes the cell to repeatedly divide and undergo mitosis. If genes involved in the cell cycle mutate, the genes that limit and regulate the cell cycle may be changed or inactive, leading cancer cells.
Organ systems.
With analogies it helps to make sentences. Cells compose tissues, as organs compose organ systems.
Answer:
Explanation: Without gene duplication, mutation of genes would not exist. This would prevent organisms from adapting to their environment, making survival much more difficult if not impossible.
