Topic 2: DNA replication theory

Question 1

Define DNA replication

2 points

Answer 1

1. When a DNA molecule COPIES ITSELF exactly,

2. producing two identical new DNA molecules

Question 2

DNA replication takes place in the _____ _______.

Answer 2

cell nucleus

because that’s where the DNA is located

Question 3

DNA needs to _____ _______ to pass on ________ __________ from one cell to another.

Answer 3

copy itself

genetic information (genes)

Question 4

Before a {cell/nucleus} is about to divide (during mitosis or meiosis) the DNA needs to _________, to double the ________, so there is enough DNA to make {two/four} new cells.

Answer 4

replicate

quantity

Question 5

What does mitosis make? (1 point)

What for? (3 points)

Answer 5

1. Makes identical cells
2. For GROWTH (extra cells)
3. REPLACEMENT of cells (which have died or have been damaged)
4. ASEXUAL REPRODUCTION

Question 6

What does meiosis make? (1 point)

what for? (1 point)

Answer 6

1. Makes GAMETES (sex cells)

2. So that genetic information can be passed to the next generation

Question 7

DNA replication takes place in the ____ phase of _________ in the cell cycle.

Answer 7

S (synthesis)

interphase (before nuclear and cell division takes place)

Question 8

Define semi-conservative replication (1 point)

Answer 8

1. replication where each of the two new DNA molecules made contains one original strand from parent DNA molecule (half is conserved) and one new strand.

Question 9

Key Summary: Describe the process of DNA replication

8 steps

Answer 9

1. It is SEMI-CONSERVATIVE replication
2. The enzyme DNA HELICASE breaks HYDROGEN bonds between the two strands in the DNA molecule and DNA strands SEPARATE
3. BOTH DNA strands act as TEMPLATES for making a new DNA strand
4. FREE DNA MONONUCLEOTIDES line up along BOTH DNA template strands
5. COMPLEMENTARY BASE PAIRING takes place between bases (A+T, C+G)
6. HYDROGEN BONDS form between COMPLEMENTARY BASES to join the two DNA strands
7. The enzyme DNA POLYMERASE joins adjacent mononucleotides with PHOSPHODIESTER BONDS IN CONDENSATION REACTIONS
8. Two new daughter DNA molecules formed are IDENTICAL TO THE ORIGINAL PARENT DNA MOLECULE and IDENTICAL TO EACH OTHER

Question 10

DNA helicase is involved in DNA replication.
What is its function in replication?
(2 points)

Answer 10

1. An enzyme which breaks the hydrogen bonds between bases in the DNA strands
2. and allows the two DNA strands to separate, to become templates

Question 11

DNA polymerase is involved in DNA replication.
What is its function in replication?
(2 points)

Answer 11

1. An enzyme which joins DNA mononucleotides with phosphodiester bonds in condensation reactions
2. to form new DNA strands