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PREPARATORY EXAMINATION
GRADE 12
LIFE SCIENCES P2
SEPTEMBER 2016
MEMORANDUM
MARKS: 150
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Life Sciences P2
Grade 12 Prep. Exam.
2
Memorandum
FS/September 2016
PRINCIPLES RELATED TO MARKING LIFE SCIENCES
1.
If more information than marks allocated is given
Stop marking when maximum marks is reached and put a wavy line and
'max' in the right-hand margin.
2.
If, for example, three reasons are required and five are given
Mark the first three irrespective of whether all or some are correct/incorrect.
3.
If whole process is given when only part of it is required
Read all and credit relevant part.
4.
If comparisons are asked for and descriptions are given
Accept if differences/similarities are clear.
5.
If tabulation is required but paragraphs are given
Candidates will lose marks for not tabulating.
6.
If diagrams are given with annotations when descriptions are required
Candidates will lose marks.
7.
If flow charts are given instead of descriptions
Candidates will lose marks.
8.
If sequence is muddled and links do not make sense
Where sequence and links are correct, credit. Where sequence and links is
incorrect, do not credit. If sequence and links becomes correct again, resume
credit.
9.
Non-recognised abbreviations
Accept if first defined in answer. If not defined, do not credit the unrecognised
abbreviation but credit the rest of answer if correct.
10.
Wrong numbering
If answer fits into the correct sequence of questions but the wrong number is
given, it is acceptable.
11.
If language used changes the intended meaning
Do not accept.
12.
Spelling errors
If recognisable accept provided it does not mean something else in Life
Sciences or if it is out of context.
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13.
If common names given in terminology
Accept provided it was accepted at the memo discussion meeting.
14.
If only letter is asked for and only name is given (and vice versa)
No credit.
15.
If units are not given in measurements
Candidates will lose marks. Memorandum will allocate marks for units
separately.
16.
Be sensitive to the sense of an answer, which may be stated in a
different way.
17.
Caption
All illustrations (diagrams, graphs, tables, etc.) must have a caption.
18.
Code-switching of official languages (terms and concepts)
A single word or two that appears in Any official language other than the
learners' assessment language used to the greatest extent in his/her answers
should be credited, if it is correct. A marker that is proficient in the relevant
official language should be consulted. This is applicable to all official
languages.
19.
No changes must be made to the marking memoranda without consulting the
provincial internal moderator.
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Life Sciences P2
Grade 12 Prep. Exam.
4
Memorandum
FS/September 2016
QUESTION 1
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.1.7
1.1.8
1.1.9
1.1.10
B
C
D
B
C
A
A
C
A
C
(10 x 2)
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.2.6
1.2.7
1.2.8
Dominant
Hydrogen bond
Chiasma
Foramen magnum 
Population
Chromatin network
Nucleopores 
tRNA
1.3.1
1.3.2
1.3.3
B only 
A only
B only
(20)
(8)
(3 x 2)
(6)
1.4.1
35 000
1.4.2
(a)
Homo habilis 
(1)
(b)
Australopithecus africanus and Australopithecus afarensis 
(2)
(c)
Homo erectus
(1)
1.4.3
Taung child
Little foot
Karabo
Mrs Ples
(Mark first ONE only)
(1)
Any 1
(1)
(6)
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Life Sciences P2
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1.5.1 (a)
(b)
1.5.2
5
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Smith's - Baby 3
(1)
Jones' - Baby 2
(1)
Solve crimes/criminal investigations
Identify organisms from their tissues
Identify family relationship
Test for specific alleles that can cause a genetic disorder
Establish matching tissues for organ transplants
Used in research into variation in populations
(Mark first THREE only)
Any 3 (3)
(5)
1.6.1 A
B
Spindle fibers
(1)
Centriole
(1)
1.6.2 Metaphase II
(1)
1.6.3 A – Pull chromosomes to poles/attachment of chromosomes
C –Hold two chromatids together/attachment of spindle fibers
(1)
(1)
(5)
TOTAL SECTION A: 50
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QUESTION 2
2.1
2.1.1 (a)
Ribosome
(1)
(b)
tRNA
(1)
(c)
translation
(1)
2.1.2
The process is transcription*
The double stranded DNA molecule unwinds/unzips
When the hydrogen bonds break
One strand is used as a template
to form mRNA (no mark)
Using free nucleotides from the nucleoplasm
The mRNA is complementary to the DNA/A-U, C-G
This process is controlled by enzymes
*indicates a compulsory mark 1*
*1+ Any (4)
2.1.3 Leucine, (Proline) Error on Paper +
(2)
2.1.4 CAT
2.2
(1)
(11)
2.2.1
Eyebrows not connected 
2.2.2
-
(5)
(1)
Parents A and B or C and D produce children with
connected eyebrows
and not connected eyebrows
Only parents both carrying the dominant allele can
produce offspring with both phenotypes
OR
-
-
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A and B or C and D have eyebrows that are not
connected, produce a child with eyebrows which are
connected
then the allele for connected eyebrows was present in
both parents,
but masked, so eyebrows that are connected is
recessive.
Any
(2)
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2.2.3
Two fertilised eggs
2.2.4
-
2.2.5
2.3
7
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FS/September 2016
(1)
One child is male and the other is female 
One child has eyebrows that are connected and the other
has eyebrows that are not connected. 
3/7 x 100 = 42,86%
2.3.1 -
(2)
(8)
Her father had brown tooth enamel. 
Therefore his genotype must have been XbY.
She could only inherit the recessive allelle Xb from her
father.
She had white teeth so she must have one dominant allele
XB therefore she must be heterozygous.
2.3.2 P1/P2 Phenotype
(2)
Brown enamel
Genotype
x
White enamel
XbY
x
XBXb 
Y
x
XB ,
Meiosis
G/gametes
Xb ,
Fertilisation
F1/F2 Genotype
XBY, XbY, XBXb, XbXb
(4)
only
1
mark
Xb 

Phenotype 1 white enamel son, 1 son with brown enamel
1 white enamel daughter, 1 daughter with
brown enamel / 1:1:1:1
P1 and F1/P2 and F2
Meiosis and fertilisation
1 Compulsory + any 5
OR
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Phenotype
Genotype
FS/September 2016
brown
enamel
XbY
x
white enamel
x
XBXb 
Gametes
XB
Xb
Xb
XBXb
XbXb
Meiosis
Fertilisation
Y
XBY
XbY
1 mark for correct gametes
1 mark for correct genotypes
F1
Phenotype
1 son with white enamel, 1 son with brown
enamel
1 daughter with white enamel, 1 daughter with
brown enamel
P1 and F1
Meiosis and fertilisation
1 Compulsory + any 6
2.4
2.4.1
Regulate chromosomal structure 
Regulate protein synthesis. /Regulate the quantity and
quality of proteins made
(Mark first TWO only)
Any 2
-
2.4.2 95% 
2.4.3
2.5
(6)
(11)
Contains sugar
Contains the nitrogenous bases, 
Contains phosphate
(Mark first THREE only)
2.5.1 (a)
(b)
(1)
(3)
(6)
Bbll
(1)
White long hair
(2)
2.5.2 BBLL
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(2)
(2)
(4)
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QUESTION 3
3.1
3.1.1
-
stands higher to get a better view of the
surroundings to search for food or spot predators
free hands for hunting/to use tools, hold their
young
body cools faster/better thermo regulation
movement became more efficient
display of sex organs for courtship/attracting mate
(Mark first TWO only)
Any 2
(2)
3.1.2
3.1.3
3.1.4
freely rotating arms 
long upper arms
elbow joints which allow rotation of forearms
rotate hands
flat nails instead of claws
opposable thumbs 
5 digits per limb
(Mark first TWO only)
Any 2 (2)
Pelvis – from narrow & long  wide and short and bowl
shape holding the weight of the body making upright
walking possible
Allows for a bigger brain
Development of speech/communication
Higher intelligence
Complex behaviour
Quick processing of information
Stores/Process large amounts of information
(Mark first TWO only)
3.2
-
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(4)
Any 2 (2)
(10)
The boabab population has been separated into two
groups
by geographical barrier
*sea/continental drift
Environments on the continents may be different
Each population undergoes natural selection
independently
and they become genotypically and phenotypically
different
This prevented them from interbreeding leading to the
formation of new species.
Any 6 (6)
Geographical barrier/*compulsory mark
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3.3
3.3.1
10
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Left-handers mirror writing are faster/slowly than righthanders.
OR
There is no difference in the speed of mirror quickly in leftand right-handers. 
3.3.2
Left-handersor right-handers
3.3.3
Same age, gender/quality of insight/
mirror size/stopwatch/pen
(2)
(1)
(First 2)
(2)
Left-handers speed in mirror is faster than right-handers
(2)
Time for mirror writing
(seconds)
3.3.4
FS/September 2016
Left-handed
Right-handed
Mark allocation of the graph
Criterion
Elaboration
Type of graph (T)
Bar graph drawn
Caption (C)
Includes both variables:
X-axis
Equal width of bars AND correct label
Y-axis
Appropriate scale AND
Correct label and units for
Drawing of bars (P) 1-bars plotted correctly – 1 mark
2 bars plotted correctly – 2 marks
NOTE: If axes are transposed:
Marks will be lost for labelling of 'X-axis 'and 'Y-axis'
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Mark
1
1
1
1
2
(6)
(13)
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3.4
3.4.1
3.4.2
3.4.3
Change in diet (vegetarian),
larger body
thicker tail
longer tail
longer toes
bigger feet
bigger bite force
(Mark first THREE only)
FS/September 2016
Any
They do not need to move quickly to catch insects/plants
are sedentary
-
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Memorandum
There is variation in the head size amongst wall lizards
in the population
some have large heads /bigger bite force and other
have smaller heads /less bite force
Insects became scares on the island /competition
occurred for food
Smaller head lizards that fed on insects struggled to
obtain food and died of hunger
While those with the larger heads fed on plants/
vegetation, had enough food to eat and survived
Those with larger heads reproduce
and pass the gene to the next generation
Resulting in an increase in number in their population
Any 6
(3)
(2)
(6)
(9)
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SECTION C
QUESTION 4
Selective breeding
-
E.g. farm animals, crops, dogs/(Any relevant example)
Organisms of a species show variations
Man selectsorganisms with traits
which will be beneficial to him
Interbreeds them with other organisms with the
same desired characteristics
to get the desired features
Choose the offspring with the best combination of characteristics 
Allow them to breed with each other
Repeat the process to improve the desired characteristics 
Max (5) + (1) for
example (6)
Similarities between natural selection, selective breeding and genetic
engineering
-
They all involve the passing on of favourable characteristics
There has to be genetic, inheritable differences
All three processes lead to genotypic
Phenotypic differences over time
And can lead to formation of new species
Max 3 (3)
Differences between natural selection, selective breeding and genetic
engineering
Natural selection
-
Environmental conditions/pressure determine survival
Organisms with less suitable characteristic die
Organisms with more suitable survival of the best adapted
No human intervention
No cost involve 
Slow process that takes many generations
Max 4 (4)
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Grade 12 Prep. Exam.
13
Memorandum
FS/September 2016
Selective breeding and genetic engineering
Characteristics that are desirable/beneficial to humansare being
selected
The characteristics are chosen by humans/It is an artificial process
It is not necessarily beneficial for the organism
Labour intensive 
May involve large costs 
Faster process
Max 4
(4)
Content: (17)
Synthesis
(3)
(20)
Criterion Relevance (R)
In this
Selective breeding
essay
example relevant and
correct and only
similarities and
differences relevant to
selective breeding,
genetic engineering
and natural selection is
given.
(There is no irrelevant
information)
Mark
1
Logical sequence (L)
Selective breeding
example discussed
logically and only
similarities and
differences relevant to
selective breeding,
genetic engineering
and natural selection is
logical discussed
1
Comprehensive (C)
Selective breeding
example is discussed
for a minimum of 4
marks similarities
between the processes
for 2 marks and
differences between
selective breeding,
genetic engineering
and natural selection
for 6 marks.
1
TOTAL SECTION C:
GRAND TOTAL:
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