BCLN BIOLOGY 12 – Rev July 2014
Unit 5 ~ Learning Guide
Name:________________
INSTRUCTIONS
Complete the following notes and questions as you work through the related lessons.
You are required to have this package completed BEFORE you write your unit test. Do
your best and ask questions about anything that you don't understand BEFORE you
write the unit test.
U5L1 NOTES: INTRODUCTION (web notes and video)
YOU SHOULD WATCH THE DNA LAB
VIDEO BEFORE PROCEEDING ANY FURTHER!
Background Information
The acronym DNA stands for ____________________
______________________. DNA is the molecule that
makes up ______________________ and serves as
__________________________________________.
Nucleic Acids
There are two types of nucleic acids, __________ and
_____________. Remember what you learned in Unit 2 both DNA and RNA are __________________ of
_______________________ (i.e., ________________
_______________________________).
They
form
genetic material and are involved in the functioning of
_____________________________________________.
U5L2 NOTES: DNA (web notes and video)
YOU SHOULD WATCH THE DNA STRUCTURE
VIDEO BEFORE PROCEEDING ANY FURTHER!
Page 1 of 10
BCLN BIOLOGY 12 – Rev July 2014
Structure
The shape of DNA is referred to as a _______________________ made up of
repeating ___________________________.
Nucleotides are composed of______ key parts:
i) _______________________________________
ii) _______________________________________
iii) ______________________________________:
1.
_______________: _____________ ring
(**larger base than Pyrimidines**)
2.
____________________:___________ ring
When the bases bond together they form the "rungs"
of the DNA ladder and do so in a set pattern. The
alternating sugar and phosphates make up the rails
(_____________). The bases make up the
______________.
 Adenine always bonds to _______________
(_______________________________)
 Guanine always bonds to _______________
(_______________________________)
This
bonding
of
bases
is
called
__________________________________________.
Page 2 of 10
BCLN BIOLOGY 12 – Rev July 2014
The bases cannot bond any other way because 2 purines would overlap and 2
pyrimidines would be too short to form the rungs of the ladder. The double strand is held
in place by hydrogen bonds between the bases. It is the _____________________
____________________________________________________ that determine what
kind of organism will develop.
 Example: ATCCGATT means something entirely different than
ACCGTTAT, just as the words Hate and Heat mean different things even
though they contain the same letters.
As a DNA strand lengthens,
______________________.
it
twists
into
a
double
spiral
called
a
Functions of DNA
1. ________________________________________________________________
________________________________________________________________
________________________________________________________________.
2. ________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________.
3. ________________________________________________________________
________________________________________________________________
________________________________________________________________.
Steps in DNA Replication
1. The DNA molecule becomes untwisted by enzymes
breaking the bonds. The two strands that make up
DNA become unzipped and each side acts as a
template. **Important** The weak hydrogen bonds
between the nitrogenous base pairs are broken by
__________________________________________.
2. New complementary nucleotides, always present in
the nucleus, move into place and pair with
complementary bases on the exposed strands.
**Important** The enzyme ____________________
assists with the complementary base pairing.

Remember: T always pairs with A
C always pairs with G
Page 3 of 10
BCLN BIOLOGY 12 – Rev July 2014
3. The adjacent nucleotides, through their sugar-phosphate components become
joined together along the newly forming chain. **Important** The enzyme
________________ glues the alternating sugar phosphate backbone together.
4. When the process is finished, 2 complete DNA molecules are present, identical
to each other and to the original molecule.
5. Both new DNA strands will now wind back up into their helical shape.
 DNA replication is called _____________________________ because
each new double helix is composed of an old (parental) strand and a new
(daughter) strand.
 Enzymes assist the unwinding process, join together the nucleotides, and
assist the rewinding process and many others.
 When errors are made in replication a ________________________ can
arise.
Recombinant DNA
Definition: __________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
A _______________ is used to introduce recombinant DNA. A _________________ is
the most common vector (they are small rings of DNA found in bacteria).
The plasmid has to be removed from the bacteria and has to have
___________________________________________________________. An enzyme
(restriction enzyme) breaks the plasmid DNA. The new foreign DNA can now be
attached to the plasmid. The enzyme, ligase, acts like the glue and sticks the foreign
DNA
to
the
plasmid
and
makes
it
whole
again.
The plasmid DNA is then ________________________________________. This
bacteria will now replicate every cell the same as the one you just put in. Eventually
there are _____________________________________________________________.
_________________________ can also be used as a vector to carry recombinant DNA
into a cell. When a virus containing Recombinant DNA infects a cell, the viral DNA
enters. Here it can direct the reproduction of many more viruses. Each virus derived
from a viral vector contains a copy of the foreign gene, therefore viral vectors allows
_____________________________________________________________________.
Viral vectors are also used to create _____________________________. A Genomic
Page 4 of 10
BCLN BIOLOGY 12 – Rev July 2014
Library is a collection of engineered viruses that carry all the genes of a species. It takes
about
10
million viruses to
carry all the
genes of
a
mouse.
Summary of Recombinant DNA
Segments of DNA (particular genes) can be inserted into bacteria and the bacteria will
go on its merry way and produce these genes. If desired genes are used - like those
that produce certain chemicals (vaccines, antibodies, etc.) then these proteins become
much more available. Protein hormones like insulin can be made using yeast cells.
____________________, a protein used in cancer treatments to help the immune
system is now ________________________________________________________.
Uses of Recombinant DNA
1. ________________________________________________________________
________________________________________________________________.
2. Identify specific genes. In 1998, the genes that mutates the cause prostate
cancer was identified.
3. ________________________________________________________________.
4. Insert genetic material into chromosomes that will help regulate cell function to
make organism genetically "better".
DNA versus RNA
Both are nucleic acids made up of ______________________.
Page 5 of 10
BCLN BIOLOGY 12 – Rev July 2014
U5L1 AND U5L2 PRACTICE: INTRODUCTION AND DNA
1. DNA and RNA are nucleic acids which are really just polymers (chains of)
____________________________ monomers. (1 mark)
2. What are the three key parts of any nucleotide? (3 marks)
a. ________________________________________________
b. ________________________________________________
c. ________________________________________________
3. In DNA, a G always pairs with a _____ whereas an A always pairs with a _____.
(2 marks)
4. Please write the complimentary sequence for the following strand of DNA (2
marks):
T A C G A C T
T T C G C A G C
__ __ __ __ __ __ __ __ __ __ __ __ __ __ __
5. If a DNA strand contains 34% adenine bases then it must also contain (3
marks):
a. __________ % thymine bases
b. __________ % guanine bases
c. __________ % cytosine bases
6. DNA replication ideally results in the formation of two identical daughter strands
of DNA. Why is it necessary for a cell to perform DNA replication? (2 marks)
Page 6 of 10
BCLN BIOLOGY 12 – Rev July 2014
7. DNA replication is termed ________________________________ as it ideally
results in two identical double helices that each contain one original "parent
strand" and one brand new, complimentary "daughter" strand. (1 mark)
8. Describe the three key steps of DNA replication in your own words. Include
what occurs, where in the cell it occurs and any enzymes that are involved for
each step. (6 marks)
Page 7 of 10
BCLN BIOLOGY 12 – Rev July 2014
9. Please complete the following chart that compares and contrasts DNA and RNA
molecules. Use the terms listed below to fill in the blanks. (8 marks)
nucleus and cytoplasm
nucleus only
one
two
single stand
double helix
smaller molecule
larger molecule
ribose
deoxyribose
A, G, C, T
A, G, C, U
DNA
mRNA, tRNA, rRNA
DNA only
controls cell activities
protein synthesis
RNA
Location in cell
Number of strands
Shape of molecule
Size of molecule
Sugar found in molecule
Nitrogenous bases
Types
Function
PLEASE REMEMBER:
YOU MUST PERFORM AND SUBMIT THE DNA LAB BEFORE THIS
UNIT IS COMPLETE! REFER TO THE UNIT 5 DROP-DOWN MENU TO
ACCESS THE LAB GUIDE AND LAB.
~ END OF BIOLOGY 12 UNIT 5 LEARNING GUIDE ~
Page 8 of 10
BCLN BIOLOGY 12 – Rev July 2014
UNIT 5 ANSWER KEY
U5L1 AND U5L2 PRACTICE: INTRODUCTION AND DNA
1. DNA and RNA are nucleic acids which are really just polymers (chains of)
____________________________ monomers. (1 mark)
2. What are the three key parts of any nucleotide? (3 marks)
a. ________________________________________________
b. ________________________________________________
c. ________________________________________________
3. In DNA, a G always pairs with a _____ whereas an A always pairs with a _____.
(2 marks)
4. Please write the complimentary sequence for the following strand of DNA (2 marks):
T A C G A C T
T T C G C A G C
__ __ __ __ __ __ __ __ __ __ __ __ __ __ __
5.
If a DNA strand contains 34% adenine bases then it must also contain (3 marks):
a. __________ % thymine bases
b. __________ % guanine bases
c. __________ % cytosine bases
6. DNA replication ideally results in the formation of two identical daughter strands of DNA. Why is
it necessary for a cell to perform DNA replication? (2 marks)
= need two identical copies of each chromosome so that when the cell divides each
daughter cell can receive a copy and thus, have all the genetic information to
function properly
7. DNA replication is termed ________________________________ as it ideally results in two
identical double helices that each contain one original "parent strand" and one brand new,
complimentary "daughter" strand. (1 mark)
Page 9 of 10
BCLN BIOLOGY 12 – Rev July 2014
8. Describe the three key steps of DNA replication in your own words. Include what occurs, where
in the cell it occurs and any enzymes that are involved for each step. (6 marks)
Step 1. = the enzyme helicase separates the complimentary strands of the double
helix by breaking the hydrogen bonds between complimentary base pairs…this forms
two separate template 9aka parent) strands that can be used to build new
complimentary strands
Step 2. = the enzyme DNA Polymerase helps bring in base pairs that are
complimentary to the parental strands
Step. 3. = the enzyme ligase works with DNA polymerase to bond the successive
bases together to form complimentary daughter strand to the parental strand thus,
forming two new, identical (barring mutation) DNA double helices (each formed by
complimenting the two original parental strands)
9. Please complete the following chart that compares and contrasts DNA and RNA molecules. Use
the terms listed below to fill in the blanks. (8 marks)
nucleus and cytoplasm
nucleus only
one
two
single stand
double helix
smaller molecule
larger molecule
ribose
deoxyribose
A, G, C, T
A, G, C, U
mRNA, tRNA, rRNA
DNA only
controls cell activities
protein synthesis
DNA
RNA
Location in cell
nucleus only
nucleus and cytoplasm
Number of strands
one
two
Shape of molecule
Double strand
Single strand
Size of molecule
Larger molecule
Smaller molecule
Sugar found in molecule
deoxyribose
ribose
Nitrogenous bases
A,G,C,T
A,G,C,U
Types
DNA only
mRNA, rRNA, tRNA
Function
Controls cell activities
Protein synthesis
Page 10 of 10