# Life Sciences Grade 12 P1 Gauteng Mock 2020 Memo (English)

> Grade 12 Life Sciences Paper 1 memorandum from the Gauteng Mock Exam 2020 (English), 13 pages. Read online or download the free PDF.

- Page: https://www.hlayiso.com/library/grade-12-nsc-life-sciences-p1-english-2020-preparatory-possible-answers/cddf92f0-b53a-4511-a865-82b8ff89c9c6
- Updated: 2026-09-27
- Subject: Life Sciences
- Grade: Grade 12
- Language: English
- Document type: Memorandum
- Year: 2020
- Exam period: Gauteng Mock Exam
- Paper: 1
- Curriculum: CAPS
- Pages: 13

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## About this document

Life Sciences · Grade 12 · Gauteng Mock Exam · 2020 · English. Memorandum, 13 pages. Read online or download the PDF.

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           PREPARATORY EXAMINATION
                          2020
             MARKING GUIDELINES

              LIFE SCIENCES (PAPER 1) (10831)

13 pages

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PRINCIPLES RELATING TO THE MARKING OF LIFE SCIENCES

1.    If more information than marks allocated is given
      Stop marking when maximum marks is reached and place a wavy line and 'max' in
      the right-hand margin.

2.    If, for example, three reasons are required and five are given
      Mark only 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 are
       incorrect, do not credit. If sequence and links become 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 the 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 are given in the terminology
      Accept, provided it was accepted at the memo discussion meeting.

14.   If only the letter is asked for and only a 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.   Changes to the marking guidelines
      No changes must be made to the marking guidelines without consulting the
      provincial internal moderator.

                                                   3

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SECTION A

QUESTION 1

1.1   1.1.1   C

      1.1.2   B

      1.1.3   C

      1.1.4   C

      1.1.5   D

      1.1.6   C

      1.1.7   A

      1.1.8   B

      1.1.9   A

      1.1.10 C
                                                (10 x 2)   (20)

1.2   1.2.1   Monoculture

      1.2.2   Blastula/blastocyst

      1.2.3   Photoreceptors/Rods and cones

      1.2.4   Glucagon

      1.2.5   Poaching

      1.2.6   Biodiversity

      1.2.7   Amniotic fluid
                                                 (7 x 1)    (7)

1.3   1.3.1   A only

      1.3.2   B only

      1.3.3   NONE
                                                 (3 x 2)    (6)

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1.4   1.4.1   Phototropism                                                                (1)

      1.4.2   Auxin                                                                       (1)

      1.4.3   B                                                                           (1)

      1.4.4   A                                                                           (1)

      1.4.5   Geotropism                                                                  (1)

      1.4.6   Root                                                                        (1)

      1.4.7   It (the shoot) would have grown straight./It would not have bent
              towards the sunlight.
              Mark first ONE only.                                              (Any 1)    (1)
                                                                                           (7)

1.5   1.5.1   A                                                                             (1)
      1.5.2   C                                                                             (1)
      1.5.3   A                                                                             (1)
      1.5.4   D                                                                             (1)
      1.5.5   B                                                                             (1)
                                                                                             (5)

1.6   1.6.1   (a) Deforestation
              (b) Overgrazing
              (c) Mining                                                                    (3)

      1.6.2   Picture 1 – CO2 /Carbon Dioxide
              Picture 2 – CH4 /Methane                                                      (2)
                                                                                             (5)

                                                                   TOTAL SECTION A:          50

                                              5

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SECTION B

QUESTION 2

2.1   2.1.1   Individual 1                                                                (1)

      2.1.2   He has the highest volume of urine produced per day.                        (1)

      2.1.3   It is an endocrine glandthat secretes the hormone directly into the
              bloodstream.                                                                 (1)

      2.1.4   Average volume of urine produced                                            (1)

      2.1.5   −   Volume of fluids the males consumed
              −   Type of fluids the males consumed/same diet
              −   Temperature of their environment
              −   The amount of physical activity 
              −   Time interval of the measurement 
              −   Method of measurement 
              −   Person doing the measurement 
                  Mark first TWO only.                                      (Any 2 x 1)    (2)

      2.1.6   −   Ensure that gloves are worn when working with urine samples.
              −   Ensure that participants’ health is being monitored by a doctor.
              −   Ensure that participants are provided with sufficient food and water.
                  Mark first ONE only.                                           (Any 1)   (1)

      2.1.7   −   They conducted the investigation over 30 days
              −   They calculated the average daily urine production                      (2)

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      2.1.8   Calculations: 2,9 + 1,5 + 1,3 + 1,0 + 1,2 = 7,9

              Individual 1: 2,9 ÷ 7,9 × 360 = 132º
              Individual 2: 1,5 ÷ 7,9 × 360 = 68º
              Individual 3: 1,3 ÷ 7,9 × 360 = 59º
              Individual 4: 1,0 ÷ 7,9 × 360 = 46º
              Individual 5: 1,2 ÷ 7,9 × 360 = 55º

                          Average volume of urine produced daily, by five
                                   different males (individuals)

                                                                     Individual 1
                                                                     Individual 2
                                                                     Individual 3
                                                                     Individual 4
                                                                     Individual 5

              Rubric for assessment of the graph
               Correct type of graph (T)                                      1
               Correct caption including both variables (C)                   1
               All 5 Sectors correctly indicated/labelled/key (L)             1
               1 – 4 Sectors correctly calculated                             1
               All 5 Sectors correctly calculated (S)                         2
               All 5 Sectors correctly drawn (D)                              1         (6)
               TOTAL                                                          6         (15)

2.2   2.2.1   It produces an alkaline fluid.                                           (1)

      2.2.2   (a) Oestrogen/progesterone
              (b) Testosterone                                                         (2)

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      2.2.3    Structure C/Female Urethra            Structure E/Male Urethra
               Transports urine only                Transports urine and semen 
               Located inside the abdomen only      Located inside the abdomen
                                                     and outside in the penis 
               Straight tube                        Curved tube 
               Short tube                           Long tube 
               Connects urinary system to the        Connects urinary and
               exterior of the body                 reproductive systems to the
                                                     exterior of the body 
              Mark first TWO only.                             (Any 2 x 2 + 1 Table (T))    (5)

      2.2.4   −     Its muscular myometrium allows for contractions during labour.
              −     It is elastic and can stretch to accommodate the growing
                    foetus. 
              −     The inner lining/endometrium has many capillaries which help to
                    form the placenta. 
              Mark first TWO only.                                        (Any 2 x 2)       (4)

      2.2.5   −     When the vas deferens is tied or sealed
              −     sperm are prevented from entering the urethra
              −     therefore, no fertilization will take place as there are no sperm
                    cells in semen 
              Mark first TWO only.                                                (Any 2)   (2)
                                                                                            (14)
2.3   2.3.1   A – Centriole/Centrosome
              B – Cell membrane/plasmalemma/plasma membrane
              C – Unreplicated/Single stranded chromosome                                  (3)

      2.3.2   Oogenesis                                                                    (1)

      2.3.3   Diagram 3                                                                    (1)

      2.3.4   −     Crossing-over*
              −     Adjacent chromatids 
              −     of homologous chromosomes cross
              −     at a point called the chiasma 
              −     There is an exchange of DNA segments /genetic material
                                                         (1 Compulsory* + Any 3) (4)

      2.3.5   (a) 23/twenty three
              (b) 46/forty six                                                             (2)
                                                                                            (11)
                                                                                            [40]

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QUESTION 3

3.1   3.1.1   A – Malleus /Hammer
              C – Cochlea                                                                   (2)

      3.1.2   Antibiotics/Grommet
              Mark first ONE only                                                         (Any
                                                                                             (1)1)

      3.1.3    −     If the vestibular part/Part B of the auditory nerve is damaged,
               −     no impulse will be sent to the cerebellum for interpretation ,
               −     therefore, the person will not be able to maintain their balance*
               −     as the cochlea part/other part of the auditory nerve
               −     is not damaged
               −     an impulse will still be able to be sent to the cerebrum for
                     interpretation, 
               −     therefore, the person can still hear*
                                                                  (2 Compulsory* + Any 2)    (4)
                                                                                             (7)

3.2   3.2.1   Chemical control                                                              (1)

      3.2.2   Mechanical/Biological control
              Mark first ONE only                                               (Any 1)      (1)

      3.2.3   (a) Access to enough, healthy food for all people at all times               (2)
              (b) Plants that do not naturally occur in an area and threaten indigenous
                  plants/crops                                                             (2)

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3.2.4   (a)
        −     Pests become resistant to pesticides, increasing their numbers
                                        OR
        −     Pesticides can damage the plant tissues of crops/kill useful
              insects or pollinators
        −     This reduces crop yields/decreased availability of food
                                        OR
        −     Pesticides are expensive, 
        −     This increases the cost of food/decreased access to food
                                        OR
        −     Chemicals in pesticides can cause illnesses in humans,
        −     This means that food is no longer healthy/safe to eat
        Mark first ONE only.                                         (Any 1 x 2)   (2)
        (b)
        −     Pesticides can be passed on through the food
              chain/bioaccumulation can occur,
        −     causing other organisms to die 
                                             OR
        −    Pesticides can damage the plant tissues of many other species of
             plants, 
        −    causing them to die
                                         OR
        −     Pesticides can run off into rivers and dams, 
        −     killing aquatic organisms. 
        Mark first ONE only.                                         (Any 1 x 2)   (2)

3.2.5   −      GMOs are more pest resistant
        −      therefore, crop yields will be higher
        −      reducing the need for pesticides
                                          OR
        −      Pests are becoming more resistant to GMOs
        −      therefore, crop yields will be lower
        −      increasing the need for pesticides                                 (3)
                                                                                   (13)

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3.3   3.3.1   (45 - 40)/5 ÷ 40 × 100 = 12,5%                                   (3)

      3.3.2   Myelin sheath                                                      (1)

      3.3.3   The wider/broader the neuron the faster the reflex action would
              be. 
                                               OR
              The narrower/thinner the neuron the slower the reflex action
              would be.                                                         (2)

      3.3.4   Synapse/Synaptic gap                                               (1)

      3.3.5           Sensory neuron showing the direction of impulse

                                 Cytoplasm

              Rubric for assessment of the diagram
               Correct type of neuron drawn (T)                           1
               Direction of impulse correct (D)                           1
               ANY 3 correct labels (L)                                   3
               TOTAL                                                      5         (5)
                                                                                  (12)

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3.4   3.4.1   C – Sclera*
              −     it protects internal/underlying structures of the eye/it is a place
                    for the attachment of muscles that move the eye/it helps
                    maintain the shape of the eye.
              Mark first ONE only.                                 (1 compulsory* +1)    (2)

      3.4.2   −      In dimmer light/walking into the house
              −      the circular muscles of the iris/part B relax
              −      the radial muscles of the iris/part B contract
              −      the diameter of the pupil/part A increases
              −      allowing more light to enter the eye.                              (4)

      3.4.3   −      The pupil will react slowly to the light /will not react
                     immediately.
              −      as alcohol inhibits autonomic actions/as the impulse reaches
                     the brain more slowly and therefore constriction will occur
                     slowly.                                                             (2)
                                                                                         (8)
                                                                                         [40]

                                                                 TOTAL SECTION B: 80

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SECTION C

QUESTION 4

Menstrual cycle (M)
−    Due to the Corpus Luteum disintegrating
−    Progesterone levels
−    decrease
−    in the blood
−    therefore, the lining of the Endometrium is shed/cannot be maintained.
−    At the same time FSH is secreted
−    by the pituitary gland/hypophysis.
−    FSH stimulates the development of a primary follicle
−    into a mature Graafian folliclein the ovary.
−    The Graafian follicle secretes oestrogen
−    which stimulates thickening of the endometrial tissue.
−    A peak in oestrogen stimulates
−    the secretion of LH by the pituitary gland/hypophysis
−    which causes the Graafian follicle to rupture
−    and release an ovum.                                               (Any 12)      (12)

Thermoregulation (T)
−    The blood vessels in the skin dilate/vasodilation occurs
−    More blood flows beneath the skin surface.
−    More heat is radiated/lost from the skin surface.
−    More blood flows to sweat glands.
−    Sweat glands become more active.
−    More sweat is released.
−    More evaporative cooling occurs.                                      (Any 5)    (5)

                                                                              Content: (17)
                                                                            Synthesis: (3)
NOTE:       NO marks will be awarded for answers in the form of a table, flow charts or
            diagrams.

ASSESSING THE PRESENTATION OF THE ESSAY
Criterion          Relevance (R)         Logical sequence (L)         Comprehensive (C)
              All information        Ideas are arranged in a      All aspects required by the
Generally     provided is relevant   logical/cause-effect         essay have been
              to the topic.          sequence.                    sufficiently addressed.
              Only information       Ideas are in a logical       Obtained at least the
              relevant to            sequence in each of the      following:
  In this     - Menstrual cycle      following:                   - Menstrual cycle (9/12)
  essay       - Thermoregulation     - Complete cycle             - Thermoregulation(3/5)
                                     - Thermoregulation
  Mark                  1                          1                           1

                                                                   TOTAL SECTION C: 20
                                                                            TOTAL: 150
                                              13

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