The answer to 2-7 would be -5, but 7-2 would be 5, depends how specific one is trying to be.
Long answer short- to reproduce cells.
Earth's crust is generally divided into older, thicker continental crust and younger, denser oceanic crust..The crust is made of solid rocks and minerals.
The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust. The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up 84% of Earth's total volume.
The core lies beneath the cool, brittle crust and the mostly-solid mantle. ... Earth's core is the very hot, very dense center of our planet. The ball-shaped core lies beneath the cool, brittle crust and the mostly-solid mantle.1
Gene regulation in eukaryotic cells is regulated by repressors as well as by transcriptional activators. Like their prokaryotic counterparts, eukaryotic repressors bind to specific DNA sequences and inhibit transcription. Any step of gene expression may be modulated, from the DNA-RNA transcription step to post-translational modification of a protein. The following is a list of stages where gene expression is regulated, the most extensively utilised point is Transcription Initiation: Chromatin domains.