00:01
Hello students, crispr -cas9 is a powerful tool used to edit dna sequence with high precision.
00:28
It stands for clustered regularly interspaced short palindromic repeats and crispr -associated protein 9.
00:38
The system is derived from the natural defense mechanism found in bacteria, where it helps them defend against viral infections.
00:49
The crispr -cas9 system consists of two main components, that is, first is crispr rna, which is abbreviated as rrna.
01:10
This is a short rna sequence that contains complementary segment to the target dna that needs to be edited and the second one is cas9 protein.
01:28
This is an enzyme that acts as a pair of molecular scissors.
01:32
It binds to the crispr rna and can cut the dna at specific locations guided by crrna.
01:43
Now we need to select all the options that provide a correct statement regarding crispr -cas9 system.
01:51
Option a is correct because crispr -cas9 is naturally occurring defense system or defense mechanism found in many bacteria and archaea as it was originally discovered as a part of immune system in these microorganisms.
02:07
When a virus infects bacterium, the crispr system captures a small piece of viral dna and stores it in the bacterial genome as a memory of the infection.
02:19
This memory is in the form of short dna sequence known as crispr arrays.
02:25
These crispr arrays are then used to guide cas9 proteins to specifically target and destroy the invading viral dna upon subsequent infections.
02:38
Next, option b is also correct.
02:43
Cas9 is a rna guided endonuclease which means it can be programmed to target and cut specific sequences in genome.
02:54
So, without the guide rna, it can cut any sequence...