1. PRACTICE QUESTIONS

2. What molecule does this diagram represent?
DNA

3. What is the circled part of the molecule called?
A strand

4. How many strands does the DNA molecule have?
Two

5. What is the circled part of the molecule called?
Nucleotide

6. What is the circled part of the nucleotide called?
Phosphate group

7. What is the circled part of the nucleotide called?
Deoxyribose (sugar)

8. What is the circled part of the nucleotide called?
Nitrogenous base

9. What is the circled part of the molecule called?
Sugar-phosphate backbone

10. How many backbones does the DNA molecule have?
Two

11. What is the circled part of the molecule called?
Base pair

12. What is the circled part of the molecule called?
Covalent bond

13. What is the circled part of the molecule called?
Hydrogen bond

14. DNA is a , stranded .
long
double
polymer
Structure

15. DNA tells ribosomes how to into . arrange amino acids protein
Function
R group
R group
R group
R group

16. A nucleotide is a of DNA.
monomer

17. There are nucleotides in DNA.4

18. Nucleotides can join together in .
any
order

19. The in DNA determines the protein that is made (the “ .”)
ATTACGACA =
AGCGGATAT=
GCCATAAGC=
order of
nucleotides
genetic
code

20. Diagram of a Nucleotide DNA = deoxyribose phosphate group nitrogenous
base
(contains phosphorus)
(contains nitrogen)
deoxyribose 5
(a -carbon )
sugar

21. Each DNA strand is held together by between the and
groups of each nucleotide.
bonds
deoxyribose
phsophate
sugar
“ “
phosphate
backbone
GIVES STRUCTURE

22. Sugar-phosphate backbone Sugar-phosphate backbone

23. The two strands are held together by between the.
bonds
nitrogenous
bases
“ ”
base
pair
GENETIC CODE

24. In DNA, always bonds with T, and C always bonds with ; this is called the - .G
rule of
base
pairing

25. There are two types of bonds in the DNA molecule.

26. The bonds in the are very , to .
covalent
backbone
strong
prevent
the
genetic
code
from
changing

27. The bonds holding the together are relatively …
hydrogen
base
pairs
weak

28. …which allows the two strands to during.
separate
replication

29. All 4 nucleotides have deoxyribose and a phosphate group, but they have different .
nitrogenous
bases
Adenine
Cytosine
Guanine
Thymine

30. A and G are (base has ). purines two rings Adenine Cytosine Guanine
Thymine

31. Looks more like a pyramid
C and T are (base has ).
pyramidines
one
ring
Adenine
Cytosine
Looks more like a pyramid
Guanine
Thymine
Purines
Pyrimidines

32. Purines always form with pyramidines. base pairs
Pyrimidine
Purine
Pyrimidine
Purine
Purine
Pyrimidine
Purine
Pyrimidine

33. The two strands in DNA are . Instead, they are to each other ( ).
not
identical
complementary
opposite

34. Use the DNA strand below to complete the complementary strand.G C G T T G T G C C G C A A C A C G

35. How did you know which nucleotides to put on the complementary strand?
Base-pairing rules G C G T T G T G C C G C A A C A C G

36. Identify the circled nucleotide as a purine or a pyramidine, and defend your answer.
One ring

37. Identify the circled nucleotide as a purine or a pyramidine, and defend your answer.
Two rings

38. Identify the circled nucleotide as adenine or thymine, and defend your answer.
Pyramidine

39. Identify the circled nucleotide as guanine or cytosine, and defend your answer.
Purine

40. If the red nucleotide is guanine, what is the purple nucleotide?
Cytosine
Base-pairing rules G

41. Explain why it is incorrect to say that the two strands in a DNA molecule are identical to each other.
Complementary
opposite