# Life Sciences Grade 12 P1 Eastern Cape Mock 2020 Memo (Eng)

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

- Page: https://www.hlayiso.com/library/life-sciences-p1-gr-12-memo-sept2020-english/9f1dd245-ec50-46c4-975d-7faf061cbdfd
- Updated: 2026-09-27
- Subject: Life Sciences
- Grade: Grade 12
- Language: English
- Document type: Memorandum
- Year: 2020
- Exam period: Eastern Cape Mock Exam
- Paper: 1
- Curriculum: CAPS
- Pages: 12

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## About this document

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

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## Document text

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                           NATIONAL
                      SENIOR CERTIFICATE

                              GRADE 12

                       SEPTEMBER 2020

                     LIFE SCIENCES P1
                    MARKING GUIDELINE

MARKS:   150

                 This marking guideline consists of 12 pages.

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2                                  LIFE SCIENCES P1                          (EC/SEPTEMBER 2020)

 PRINCIPLES RELATED TO MARKING LIFE SCIENCES

 1.     If more information than marks allocated is given
        Stop marking when maximum marks are 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 a part of it is required
        Read all and credit the relevant part.

 4.     If comparisons are asked for, but descriptions are given
        Accept if the 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 the answer, provided it does not mean something
        else in Life Sciences or if it is out of context.

 13.    If common names are given in terminology
        Accept, provided it was accepted at the national memo discussion meeting.

 14.    If only the letter is asked for, but only the name is given (and vice
        versa)
        Do not credit.

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(EC/SEPTEMBER 2020)                        LIFE SCIENCES P1                                   3

 15.    If units are not given in measurements
        Candidates will lose marks. Marking guidelines 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 appear(s) in any official language other than the
        learner’s 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.

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4                                  LIFE SCIENCES P1   (EC/SEPTEMBER 2020)

 SECTION A

 QUESTION 1

 1.1   1.1.1     C 
       1.1.2     B 
       1.1.3     B 
       1.1.4     D 
       1.1.5     B 
       1.1.6     C 
       1.1.7     B 
       1.1.8     D                                      (8 x 2)   (16)

 1.2   1.2.1     Vasodilation 
       1.2.2     Hypothalamus 
       1.2.3     Negative feedback 
       1.2.4     Parasympathetic system 
       1.2.5     Aldosterone 
       1.2.6     Synapse 
       1.2.7     Placenta                               (7 x 1)     (7)

 1.3   1.3.1     None 
       1.3.2     A only 
       1.3.3     A only                                (3 x 2)     (6)

 1.4   1.4.1     (a)   A                                            (1)
                 (b)   E                                            (1)
                 (c)   B                                            (1)
                 (d)   F                                            (1)

       1.4.2     Spinal cord                                        (1)

       1.4.3     Reflex action                                      (1)

       1.4.4     Brain  and the spinal cord                        (2)

       1.4.5     (a)   C                                            (1)
                 (b)   D                                            (1)

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(EC/SEPTEMBER 2020)                        LIFE SCIENCES P1                                   5

 1.5   1.5.1     (a)   A – Vagina                                                           (1)
                 (b)   B – Cervix                                                           (1)
                 (c)   F – Uterus                                                           (1)

       1.5.2     (a)   C  endometrium                                                      (2)

                 (b)   D  Ovary                                                            (2)
                 (c)   E    Fallopian tube                                                 (2)
       1.5.3     Sperm will not be able to fertilise the ovum / sperm will not be able
                 to reach ovum and cause fertilisation                                       (1)
       1.5.4     Both ovaries release ova  alternately                                      (1)

                                                                  TOTAL SECTION A:           50

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6                                       LIFE SCIENCES P1                          (EC/SEPTEMBER 2020)

 SECTION B

 QUESTION 2

 2.1    2.1.1        (a)     Prophase I                                                          (1)

                     (b)     Metaphase I                                                         (1)

        2.1.2        (a)     A – Centromere                                                      (1)

                     (b)     B – Homologous chromosomes  / Chromosomes                           (1)

                     (c)     D – Centriole                                                       (1)

        2.1.3        -     Homologous chromosomes lie side by side 
                     -     Chromatids from the paternal and maternal chromosomes 
                     -     Establish contact points called chiasmata  and
                     -     Exchange genetic material between chromatids  and
                     -     This is known as crossing over                      (Any 4)           (4)

        2.1.4        -     Homologous chromosomes randomly arrange themselves 
                     -     on either side of the equator  and this
                     -     leads to the formation of new combinations of genetically
                     -     different  chromosomes
                     -     in the daughter cells (gametes) causing variation* in the next
                           generation                           (1* compulsory point + any 2)     (3)

 2.2    2.2.1        Altricial  development                                                      (1)

        2.2.2        -      Eyes closed 
                     -      no down feathers covering the body  / bodies naked
                     -      unable to feed themselves 
                           (Mark first THREE only)                                                (3)

        2.2.3        -     Complete dependence on parents  until fully developed
                                                           OR
                     -     unable to defend/move 
                     -     therefore, they are an easy target for predation            (Any
                           1)                                                                     (1)

        2.2.4        -     The egg yolk that supplies nutrients to the developing embryo is
                           small  therefore,
                     -     the hatchlings are unable to develop fully  before hatching           (2)

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(EC/SEPTEMBER 2020)                          LIFE SCIENCES P1                                    7

 2.3 2.3.1      Long/far-sightedness  (Hypermetropia)                                          (1)

       2.3.2    -     Eye ball is too rounded 
                -     due to the inability of the lens of the eye to become more convex 
                -     therefore, the image of the near object that falls on the retina is
                      blurred while
                -     the most clearly focussed image falls behind the retina                  (4)

       2.3.3    It can be corrected with a convex lens 
                (Mark first ONE only)                                                           (1)

       2.3.4    -     The radial muscles of the iris contract 
                -     the circular muscles relax 
                -     the pupil dilates 
                -     the amount of light entering the eye is increased                        (4)

 2.4 2.4.1      Luteinizing hormone (LH)                                                       (1)

       2.4.2    The highest level of LH causes ovulation                                       (1)

       2.4.3    13th day of the cycle                                                          (1)

       2.4.4    -     High level of oestrogen / an increase in level of oestrogen causes
                      the endometrium to become more
                -     vascular and spongy/thicker                                              (2)

       2.4.5    Progesterone                                                                   (1)

       2.4.6    -     The maintenance of high levels of progesterone / hormone B after
                      28 days indicates pregnancy 
                -     hormone B / progesterone is required to maintain pregnancy /
                      maintain the endometrium                                                  (2)

       2.4.7    -     High levels of progesterone inhibit the secretion of FSH in order to
                      stop the development of new follicles  and
                -     cause ovulation  / no new ova produced
                -     during pregnancy / disrupts pregnancy                                     (3)
                                                                                                [40]

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8                                    LIFE SCIENCES P1                         (EC/SEPTEMBER 2020)

 QUESTION 3

 3.1 3.1.1      Thyroid gland                                                                (1)

       3.1.2    Treatment of thyroxin  / substance tadpoles were treated with                (1)

       3.1.3    -     Quantity of NaOH and thyroxin treatment 
                -     Time of treatment/ feeding 
                -     Time of collecting data 
                -     Size of tadpoles 
                -     Type of nutrients 
                -     Quantity of nutrients 
                -     Level of activity / area of captivity 
                -     Environmental conditions 
                -     Method of determining the body mass 
                     (Mark first TWO only)                                          (Any 2)   (2)

       3.1.4    The initial body mass  taken before the treatment                            (1)

       3.1.5    -    High levels of thyroxin  in the body
                -    increase the rate of metabolism 
                -    More glucose will be oxidised / more of their fuel reserves
                     are used up
                -    to release more energy / allowing them to be more active
                -    this leads to drop in the body mass                                      (4)

       3.1.6    -    When the thyroxin level drops below normal limits
                -    pituitary gland / hypophysis is stimulated 
                -    Pituitary gland secretes more TSH 
                -    High TSH level stimulates the thyroid gland 
                -    The thyroid gland secretes more thyroxin 
                -    The thyroxin level thus increases 
                -    Thyroxin level returns to normal                                         (5)

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(EC/SEPTEMBER 2020)                           LIFE SCIENCES P1                                  9

 3.2 3.2.1      (a)    B – Medulla oblongata                                                   (1)

                (b)    C – Corpus callosum                                                     (1)

                (c)    E – Cerebellum                                                          (1)

       3.2.2    (a)    -  It conducts impulses between the brain and the receptors /
                          effectors 
                       - Serves as a reflex centre for actions  such as blinking,
                          sneezing, coughing etc.                                (Any 1)        (1)
                         (Mark first ONE only)

                (b)    -    Cerebro-spinal fluid in the central canal supplies nutrients and
                            oxygen for nerve cells / removes CO2 and waste products
                            from the nerve cells / protects the brain and spinal cord against
                            physical injury
                           (Mark first ONE only)                                                (1)

       3.2.3    (a)    -   During a haemorrhage, the blood leaks out of the blood
                           capillaries 
                       -   and this disrupts the supply of oxygen and nutrients to the
                           nerve cells / removal of CO2 and metabolic waste causing
                           them to die  / causes excessive pressure                            (3)

                (b)    -   Loss of sensation  / consciousness / unable to process
                           impulses from sense organs
                       -   loss of higher intellectual abilities  such as memory,
                           judgement, reasoning. etc.
                       -   unable to initiate voluntary muscular actions                       (3)

 3.3 3.3.1      Auxin                                                                          (1)

       3.3.2    Auxin is present / produced at the growing tip  of stem or root                (1)

       3.3.3    To cancel the effect of unilateral light on plumule growth  / to show
                that the light has no effect on the upward bending of plumule / to
                exclude a phototropic response                                                  (1)

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10                                    LIFE SCIENCES P1                          (EC/SEPTEMBER 2020)

       3.3.4    When a plumule is placed horizontally:

                -    Auxins are attracted by gravity 
                -    There is a high concentration of auxins on the lower side of the
                     plumule 
                -    which stimulates growth / cell elongation / cell division on the lower
                     side 
                -    There is a low concentration of auxins on the upper side of the
                     plumule 
                -    which inhibits growth / cell elongation / cell division on the upper
                     sides
                -    The lower side of the plumule grows faster / uneven growth
                     occurs causing the plumule to grow/ bend upwards 
                -    The plumule grows away from gravity*/ the plumule is negatively
                     geotropic
                     1* Compulsory mark + (Any 3)                                                   (4)

       3.3.5    The germinating seed is attached to the disc of rotating clinostat                 (1)

 3.4 3.4.1      -    Has a protective function 
                -    Acts as a climate control system for the testes  / temperature
                     control
                     (Mark first TWO only)                                                          (2)

       3.4.2    Epididymis                                                                         (1)

       3.4.3    -    Fertility is reduced 
                -    because the temperature is always high 
                -    This will lead to production of abnormal sperms / fewer
                     sperm are formed / proteins in the cells that form the sperm will
                     denature

                                                     OR

                -    Fertility is reduced 
                -    because the pressure is increased / reducing circulation of the
                     blood
                -    This will lead to the production of abnormal sperm / Fewer sperms
                     are formed                                                                     (3)

       3.4.4    Take regular breaks  while driving long distances                               (1)
                                                                                                [40]

                                                                      TOTAL SECTION B:              80

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(EC/SEPTEMBER 2020)                      LIFE SCIENCES P1                                 11

 SECTION C

 QUESTION 4

       The process that led to an increased breathing rate:
       -   The adrenal gland 
       -   secretes more adrenalin into the blood 
       -   An increased level of carbon dioxide  in the surrounding area due to the
           heavy smoke
       -   causes carbon dioxide levels in the blood to increase above the normal
           levels 
       -   Receptor cells in the carotid artery in the neck are stimulated 
       -   to send impulses to the medulla oblongata in the brain 
       -   Medulla oblongata stimulates breathing muscles (intercostal muscles and
           diaphragm) 
       -   and heart 
       -   Breathing muscles contract more actively 
       -   Increases the rate and depth of breathing 
       -   The heart beats faster 
       -   More carbon dioxide is taken to and exhaled from the lungs 
       -   causing the breathing rate to increase
                                                                               Max. 10    (10)

       Restoring balance

       Balance is achieved in the following way:

       -   The maculae 
       -   in the utriculus and sacculus  and
       -   the cristae 
       -   in the semi-circular canals are stimulated 
       -   They generate impulses 
       -   which are transmitted through the auditory nerve 
       -   to the cerebellum 
       -   where they are interpreted 
       -   Impulses are transmitted via the motor neuron 
       -   to skeletal muscles 
       -   to restore balance
                                                                              Max. 7 (7)
                                                                             Content (17)
                                                                           Synthesis (3)
                                                                                     (20)

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12                                     LIFE SCIENCES P1                       (EC/SEPTEMBER 2020)

 ASSESSING THE PRESENTATION OF THE ESSAY

            Relevance                     Logical sequence               Comprehension

  All information provided is      Ideas arranged in a logical/    Answered all aspects
  relevant to the question         cause-effect sequence           required by the essay in
                                                                   sufficient detail

  All information is relevant to   The sequence of events          The following must be
  the:                             and facts in the:               included:

  -   Process that led to an       -    Process that led to an     -   Process that led to an
      increased breathing rate          increased breathing rate       increased breathing rate
  -   Restoring balance            -    Restoring balance              (B) – (7/10)

  There is no irrelevant           Are in a logical sequence       -   Restoring balance
  information                                                          (R) – (4/7)

              1 mark                           1 mark                         1 mark

                                                                       TOTAL SECTION C:             20
                                                                          GRAND TOTAL:             150

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