DNA Replication

Question 1

What is DNA replication?

Answer 1

• the process of making a new DNA molecule from an existing DNA molecule that is identical to the original molecule

Question 2

When and where does DNA replication take place?

Answer 2

• in the nucleus
• during the interphase (in between cell divisions)

Question 3

Why is DNA replication necessary?

Answer 3

• to ensure that the genetic code is passed on to each new daughter cell formed during cell division

Question 4

What catalyses the process of DNA replication?

Answer 4

• the enzyme DNA polymerase

Question 5

How is a new chromosome formed during DNA replication?

Answer 5

1. the double helix unwinds
2. the weak hydrogen bonds holding the base pairs together break, allowing the two strands to part
3. each single chain of bases is exposed
4. free nucleotides in the cytoplasm become attached to their matching, exposed base partners
5. the 2 daughter DNA molecules each twist to form a double helix which then winds itself around the histones, forming a chromosome

Question 6

What ensures that the sequence of the bases in the daughter DNA is exactly the same as in the parent DNA?

Answer 6

• the fact that A will only bond with T
• and C will only bond with G

Question 7

What does one DNA double helix become after DNA replication?

Answer 7

• one DNA double helix becomes 2 identical double helices