Amoeba sisters

Question 1

Why does DNA need to replicate before cells divide? (2 reasons)

Answer 1

1) To prevent major copying errors because it’s hard to copy DNA and build a new cell in mitosis

2) You need to copy the Key Information first, then have a cell to put it into

Question 2

Describe the role of Helicase

Answer 2

Helicase (Unzipper): Unzips the bases by breaking Hydrogen bonds(

Question 3

Describe the role of DNA Polymerase

Answer 3

DNA Polymerase(Builder): Builds new strands of DNA

Question 4

Describe the role of Primase?

Answer 4

Primase (gives directions/PRIMES THE POLYMERASE: Tells polymerase WHERE to start building

Question 5

Describe the role of Ligase

Answer 5

Ligase(Gluer): Glues/Binds DNA fragments together

Question 6

Describe the first step in DNA replication

Answer 6

Helicase unzips the DNA strand into the leading and lagging strands

Question 7

Describe the second step in DNA replication

Answer 7

Primase signals to DNA Polymerase where to begin DNA replication

Question 8

Describe the THIRD step in DNA replication

Answer 8

DNA Polymerase starts at the point of origin signaled by DNA Primase and begins replicating/copying bases on the leading strand

Question 9

Describe the FOURTH step in DNA replication?

Answer 9

On the leading strand, DNA Polymerase copies DNA in one continuous stream (BECAUSE IT COPIES ONLY 5 Prime to 3 Prime)

On the lagging strand, DNA polymerase has to “hopscotch” and copy in segments. These segments are called Okazaki fragments and are held together by Ligase.

Question 10

What is meant by the lagging strand? and why does this occur?

Answer 10

The lagging strand is one of two strands of DNA found at the replication fork or junction, in the double helix. The other strand is called the leading strand.

A lagging strand needs a slight delay before going through replication, and it goes through replication in small fragments called okazaki fragments. (IT LITERALLY LAGS IN THE REPLICATION PROCESS)