Okay kiddo, let's talk about something called the genome. The genome is like a set of instructions that tells your body how to grow and work properly. It's a bit like a recipe book for your body.
Now, scientists have discovered a way to make changes to the genome, using a tool called CRISPR-Cas9. It's like a pair of tiny scissors that can snip and cut bits of the genome.
So, a genome-wide CRISPR-Cas9 knockout screen is like a big experiment where scientists use those tiny scissors to chop out different bits of the genome, one by one. They do it for every single bit of the genome, just like testing every recipe in a cookbook.
They want to see what happens when they snip out certain bits of the genome. Does it change the way the body grows or works? Does it make any difference at all?
By doing this experiment, scientists can learn more about how the genome works, what different genes do, and even find the ones that might be causing certain diseases. It's like looking for clues to solve a mystery.
So even though it's a really complicated process, all these scientists are doing is playing a big game of "guess what happens if we cut this bit?" to try and learn more about how our bodies work!