Name: ______________________________ Period: _____ Date: _________________________
Pretest Ch 12: DNA
Matching. Match the word on the right with the correct definition on the left.
1. _______ the structure that forms when DNA
is “unwound” to be copied
2. _______ the strand that takes longer to copy,
is copied in fragments, not all at once
3. _______ besides sugar, the other molecule that
makes up the “sides” of the DNA
molecule; PO3 44. _______ A & T or G & C when they match up
5. _______ the twisted ladder shape that DNA forms
A. complementary base pair
B. DNA
C. DNA helicase
D. DNA polymerase
E. deoxyribose
F. double helix
G. enzyme
H. hydrogen bond
I. lagging strand
J. leading strand
K. mutation
L. nitrogenous base
M. nucleotide
N. phosphate group
O. replication fork
P. semi-conservative
6. _______ the 5-carbon sugar that makes up the
“sides” of the DNA molecule
7. _______ when something goes wrong with
DNA replication
8. _______ molecule that controls cell functions
by making proteins
9. _______ the strand of DNA that is copied as one big piece, instead of small
fragments
10. _______ what holds the nitrogen bases are held together to form the “rungs” of the
DNA ladder
11. _______ enzyme responsible for making new DNA strands
12. _______ chemical that controls a function in the cell or body by running a
chemical reaction
13. _______ the subunit of DNA; DNA is made of many of these put together; it has
three parts
14. _______ DNA replication is called this because, for the two new strands, one is the
original and one is a copy
15. _______adenine, cytosine, guanine and thymine; they make up the “rungs” of the
DNA ladder
16. _______enzyme responsible for “unzipping” the DNA molecule so it can be copied
Prokaryotic DNA replication is different than eukaryotic. How…?
17. What shape does prokaryotic DNA have?
18. How many replication forks does it have?
19. Describe the process of prokaryotic DNA replication.
DNA replication really happens in three steps. Describe each step and the enzyme
involved:
20. Step 1:
22. Step 2:
24. Step 3:
Here is a picture of the DNA molecule and a close up of its structure. Identify the
following….
26. ______________________ the shape
of the whole structure
27. ______________________ the little
black circle
28. ______________________ the
pentagon
27.
29.
28.
31.
30.
29. ______________________ the
rectangle
30. ______________________ the lines
in between the circles,
pentagons and rectangles
33.
31. ______________________ the lines
between rectangles
32. ______________________ the
structure inside the
rectangle
32.
33. ______________________ the structure inside the rectangle
34. Fill in the matching letters in the column of rectangles on the left.
26.
Answer Key___
Name: __
Period: _____ Date: _________________________
Pretest Ch 12: DNA
Matching. Match the word on the right with the correct definition on the left.
O___ the structure that forms when DNA
1. ___
is “unwound” to be copied
I
A. complementary base pair
B. DNA
2. ___ ___ the strand that takes longer to copy,
is copied in fragments, not all at once
C. DNA helicase
D. DNA polymerase
3. ___
E. deoxyribose
F. double helix
G. enzyme
N___ besides sugar, the other molecule that
makes up the “sides” of the DNA
molecule; PO3 4-
A___ A & T or G & C when they match up
4. ___
F___ the twisted ladder shape that DNA forms
5. ___
E___ the 5-carbon sugar that makes up the
6. ___
“sides” of the DNA molecule
K___ when something goes wrong with
7. ___
DNA replication
B___ molecule that controls cell functions
8. ___
H. hydrogen bond
I. lagging strand
J. leading strand
K. mutation
L. nitrogenous base
M. nucleotide
N. phosphate group
O. replication fork
P. semi-conservative
by making proteins
J___ the strand of DNA that is copied as one big piece, instead of small
9. ___
fragments
H__ what holds the nitrogen bases are held together to form the “rungs” of the
10. __
DNA ladder
D___ enzyme responsible for making new DNA strands
11. ___
G___ chemical that controls a function in the cell or body by running a
12. ___
chemical reaction
M___ the subunit of DNA; DNA is made of many of these put together; it has
13. ___
three parts
P__ DNA replication is called this because, for the two new strands, one is the
14. ___
original and one is a copy
L___adenine, cytosine, guanine and thymine; they make up the “rungs” of the
15. ___
DNA ladder
C___enzyme responsible for “unzipping” the DNA molecule so it can be copied
16. ___
Prokaryotic DNA replication is different than eukaryotic. How…?
17. What shape does prokaryotic DNA have?
Circular rather than strands
18. How many replication forks does it have?
2…starts at one point and goes both ways
around the circle
19. Describe the process of prokaryotic DNA
replication.
starts at one point and
goes both ways around the
circle
DNA replication really happens in three steps. Describe each step and the enzyme
involved:
20. Step 1:
DNA helicase
“unwinds” the DNA
molecule (breaks
hydrogen bonds)
22. Step 2:
DNA
polymerase adds
new complementary base pairs (A with T, G
with C)
24. Step 3:
DNA polymerase “rezips” and checks the
two new molecules for mistakes. There’s one
strand (leading strand)
that gets copied as one
long piece. There
another (lagging strand)
that is “upside down”
(antiparallel) and gets
copied in pieces
(Okazaki fragments)
and those get put together.
Here is a picture of the DNA molecule and a close up of its structure. Identify the
following….
Double helix__ the
26. _
A
shape of the whole structure
phosphate__ the little
27. __
black circle
deoxyribose
(sugar)_ the pentagon
28. __
nitrogen base__ the
29. _
rectangle
covalent bond__ the
30. _
lines in between the circles,
pentagons and rectangles
Hydrogen bond_ the
31. __
27.
28.
29.
31.
G
30.
T
A
C
33.
G
32.
lines between rectangles
nucleotide_ the structure inside the rectangle
32. __
26.
complementary base pair__ the structure inside the
33. __
rectangle
34. Fill in the matching letters in the column of rectangles on the left.
From top to bottom… A G T A C G