CONJUCTION EXERCISE (edit the following passage about DNA fingerprinting)

Hello ! I am having some problem about conjunction . Is anyone can help me with this ? thanks.

Directions: Edit the following passage. Number your page. There is one sentence that is correct; you may write "correct" next to that number. For the other three sentences, correct the punctuation error. (There may be a comma where there should be a semicolon. Or a semicolon may be used when some other punctuation should be used.)

1. DNA fingerprinting is a technique that can be used to identify a person accurately, it is also known as DNA profiling. 2. DNA is present in cells and can be isolated from the following; blood, skin, hair, and sweat. 3. DNA fingerprinting can be used to diagnose inherited disorders in fetuses and newborn babies; it can be used to study and research genetic disorders; it is also a key took in determining paternity or maternity. 4. Criminal identification and forensics rely on DNA fingerprinting to connect suspects to biological evidence; and it has proven a very precise method by which to convict suspects.

( This is my work , but i am not sure it is correct or not ) .
1. DNA fingerprinting is a technique that can be used to identify a person accurately ; it is also known as DNA profiling. 2. DNA is present in cells and can be isolated from the following blood, skin, hair, and sweat. 3. DNA fingerprinting can be used to diagnose inherited disorders in fetuses and newborn babies; it can be used to study and research genetic disorders; it is also a key took in determining paternity or maternity. 4. Criminal identification and forensics rely on DNA fingerprinting to connect suspects to biological evidence , and it has proven a very precise method by which to convict suspects.

My version:

1. DNA fingerprinting is a technique that can be used to identify a person accurately. I t is also known as DNA profiling. 2. DNA is present in cells and can be isolated from the following: blood, skin, hair, and sweat.

Last two are same as yours.

In the first one, I've replaced the comma with a period. As for the second, a colon looks correct in place of the semi-colon.

Thanks so much . ;-)

Don't put a space before the comma. That was probably just a typo...

Anyway, I think you two figured it out correctly. Do you have questions about why Ershad added that colon, did a sentence break, etc?