What is special about “knockout” mice?

their DNA has been modified

they are easy to knock out

they are very attractive

None of these

What is special about “knockout” mice their DNA has been modified

"ناک آؤٹ" چوہوں میں کیا خاص بات ہے ان کے ڈی این اے میں ترمیم کر دی گئی ہے۔