Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
CAPE WINELANDS EDUCATION
DISTRICT
LIFE SCIENCES PAPER 2
SURVIVAL KIT
DNA, RNA, Protein Synthesis (Paper 2- 27 marks)
DNA is the basic unit of genetics.
1
,Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
DNA provides the code for production of proteins, a process called protein synthesis.
There are two types of nucleic acids: DNA and RNA
DNA is found (or located) in the nucleus of cells
is also found in the mitochondria of cells
RNA is found in the nucleus
also found at the ribosomes in the cytoplasm of a cell.
RNA plays a role in protein synthesis by joining amino acids in the correct
sequence, according to the instructions which DNA provides
Brief history of the discovery of the DNA molecule :
Franklin & Wilkins: did research on structure of DNA, they took X-rays of the DNA
molecule
Watson & Crick: formulated the double helix structure of the DNA molecule by using a
three dimensional (3D) model
STRUCTURE OF DNA: Double helix
Consists of two strands of nucleotides that form a twisted ladder (double helix)
Double Helix
A DNA molecule is made up of building-blocks or monomeres, called nucleotides
NB : Each DNA nucleotide is made up of three components:
1. Nitrogenous bases linked by weak hydrogen
bonds
The four nitrogen bases: adenine (A)
thymine (T)
cytosine (C)
guanine (G)
2. Sugar portion (deoxyribose in DNA)
3. Phosphate portion
Specific base pairing arrangement are known as
complimentary bases.
A always pairs with T (A-T)
C always pairs with G (C-G)
NB!!: Nitrogen bases attach to the sugar portion of the
nucleotide
2
,Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
Know the stick diagram of DNA to
illustrate its structure:
When you learn this topic, practice to
draw a nucleotide AND
be able to label the different parts of the
DNA stick diagram
FUNCTIONS OF DNA:
1. Sections of DNA-forming genes carry hereditary information
2. DNA contains coded information for protein synthesis
PROCESS OF DNA REPLICATION
(Meaning of replicate = to make an exact copy of)
When does DNA replication take place?
During INTERPHASE
Where does DNA replication take place?
In the nucleus
Significance (or importance) of DNA replication:
• Doubles the genetic material so it can be shared between the resulting daughter cells
during cell division.
• Results in the formation of identical daughter cells during mitosis
How DNA replication takes place:
(you must be able to describe this process)
3
, Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
Definition of a DNA profile:
It can be described as an arrangement of black bars representing DNA fragments of the
person.
Uses of DNA profiles:
• Identify criminals
• Identify dead bodies
• Identify relatives
• Identify paternity
Interpretation of DNA profiles:
Compare the DNA profile found at the crime scene to the DNA profile of the suspects.
Suspect 2 is most probably guilty as all the bars on his DNA profile are the same as the
bars
of the DNA profile found at the crime scene.
Typical question in the exams:
Describe the process of DNA replication. (5)
- The double helix unwinds
- Weak hydrogen bonds between the nitrogen bases break, DNA
unzips (separates)
- Both of the original strands serve as a template on which the
complement is built
- Free DNA nucleotides build a strand onto each of the two DNA strands,
attaching to their complementary bases
- Two identical DNA molecules are formed, each consisting of one original and
one new strand
4
CAPE WINELANDS EDUCATION
DISTRICT
LIFE SCIENCES PAPER 2
SURVIVAL KIT
DNA, RNA, Protein Synthesis (Paper 2- 27 marks)
DNA is the basic unit of genetics.
1
,Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
DNA provides the code for production of proteins, a process called protein synthesis.
There are two types of nucleic acids: DNA and RNA
DNA is found (or located) in the nucleus of cells
is also found in the mitochondria of cells
RNA is found in the nucleus
also found at the ribosomes in the cytoplasm of a cell.
RNA plays a role in protein synthesis by joining amino acids in the correct
sequence, according to the instructions which DNA provides
Brief history of the discovery of the DNA molecule :
Franklin & Wilkins: did research on structure of DNA, they took X-rays of the DNA
molecule
Watson & Crick: formulated the double helix structure of the DNA molecule by using a
three dimensional (3D) model
STRUCTURE OF DNA: Double helix
Consists of two strands of nucleotides that form a twisted ladder (double helix)
Double Helix
A DNA molecule is made up of building-blocks or monomeres, called nucleotides
NB : Each DNA nucleotide is made up of three components:
1. Nitrogenous bases linked by weak hydrogen
bonds
The four nitrogen bases: adenine (A)
thymine (T)
cytosine (C)
guanine (G)
2. Sugar portion (deoxyribose in DNA)
3. Phosphate portion
Specific base pairing arrangement are known as
complimentary bases.
A always pairs with T (A-T)
C always pairs with G (C-G)
NB!!: Nitrogen bases attach to the sugar portion of the
nucleotide
2
,Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
Know the stick diagram of DNA to
illustrate its structure:
When you learn this topic, practice to
draw a nucleotide AND
be able to label the different parts of the
DNA stick diagram
FUNCTIONS OF DNA:
1. Sections of DNA-forming genes carry hereditary information
2. DNA contains coded information for protein synthesis
PROCESS OF DNA REPLICATION
(Meaning of replicate = to make an exact copy of)
When does DNA replication take place?
During INTERPHASE
Where does DNA replication take place?
In the nucleus
Significance (or importance) of DNA replication:
• Doubles the genetic material so it can be shared between the resulting daughter cells
during cell division.
• Results in the formation of identical daughter cells during mitosis
How DNA replication takes place:
(you must be able to describe this process)
3
, Life Sciences Cape Winelands Updated Survival Kit PAPER 2 2024
Definition of a DNA profile:
It can be described as an arrangement of black bars representing DNA fragments of the
person.
Uses of DNA profiles:
• Identify criminals
• Identify dead bodies
• Identify relatives
• Identify paternity
Interpretation of DNA profiles:
Compare the DNA profile found at the crime scene to the DNA profile of the suspects.
Suspect 2 is most probably guilty as all the bars on his DNA profile are the same as the
bars
of the DNA profile found at the crime scene.
Typical question in the exams:
Describe the process of DNA replication. (5)
- The double helix unwinds
- Weak hydrogen bonds between the nitrogen bases break, DNA
unzips (separates)
- Both of the original strands serve as a template on which the
complement is built
- Free DNA nucleotides build a strand onto each of the two DNA strands,
attaching to their complementary bases
- Two identical DNA molecules are formed, each consisting of one original and
one new strand
4
