KWAZULU NATAL PROVINCE LIFE SCIENCES - 2018 MATRIC INTERVENTION

 
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KWAZULU NATAL PROVINCE LIFE SCIENCES - 2018 MATRIC INTERVENTION
Life Sciences         SADTU        Revision document

                KWAZULU NATAL PROVINCE
                       2018
                 MATRIC INTERVENTION

                   LIFE SCIENCES

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KWAZULU NATAL PROVINCE LIFE SCIENCES - 2018 MATRIC INTERVENTION
Life Sciences        SADTU                  Revision document

                  CURRICULUM GRADE 12

                REVISION SUPPORT DOCUMENT

                LIFE SCIENCES
                     2018

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KWAZULU NATAL PROVINCE LIFE SCIENCES - 2018 MATRIC INTERVENTION
Life Sciences                              SADTU                                            Revision document

This document is developed in order to assist both learners and educators to improve the pass rate in Life
Sciences.
Most important aspects to note in order to obtain better results in Life Sciences are as follows:
1.        Understanding of Biological terms
2.        Knowing the relevant diagrams and ability to label different pats in a diagram
3.        Knowing the function(s) of each label
4.        In some cases, know how the particular structure is suited for its function(s)
5.        Drawing of graphs e.g. Bar graph, Histogram, Line graph and Pie chart.
6.        Application of the gained knowledge to different and practical situations.
PAPER 1
Content
     1. Meiosis
     2. Reproduction in Vertebrates
     3. Human reproduction
     4. Animal Response to the environment
        - Nervous System
        - Endocrine System
     5. Homeostasis
     6. Plant response to the environment
     7. Human Impact to the environment

PAPER 2
Content
          1.   Nucleic Acids (DNA – Code of life, RNA and Protein Synthesis
          2.   Meiosis
          3.   Genetics
          4.   Evolution
          5.   Human Evolution
                       PAPER 1
Reproduction in Vertebrates
Terminology
       TERM                                         DESCRIPTION
Allantois                 Structure in a developing embryo that is used for gaseous exchange
Amnion                    Inner membrane in an embryo containing fluid that acts as a shock-
                          absorber
Amniotic egg              An egg containing FOUR extra-embryonic membranes
Chorion                   Outer membrane in a developing embryo that plays a role in
                          gaseous exchange
Yolk sac                  Structure in an amniotic egg that provides nutrients to a developing
                          embryo

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Fertilization            Fusion of a male and a female gametes to form a zygote
Internal fertilization   Fusion of an egg cel with a sperm cell that occurs inside the female
                         reproductive system
External fertilization   Fusion of an egg with a sperm cell that occurs outside the female
                         reproductive system.
Ovipary                  Kind of reproduction where an egg is laid and hatches outside the
                         female body. Nutrients obtained from an egg. No placenta
Ovovivipary              Kind of reproductive strategy where an egg hatches inside the
                         female body. Nutrients obtained from an egg. No placenta
Vivipary                 Kind of reproductive strategy where young obtains nutrients from
                         the mother. Presence of placenta
Precocial                Production of offspring that are independent. They can move, feed
development              and well developed sight
Altricial                Production of offspring that are highly dependent to the mother.
development              Cannot move, feed and have poor eye-sight

Question 1
1.1     The structure in the amniotic egg that supplies nutrients
        A       Shell
        B       Allantois
        C       Chorion
        D       Yolk sac
        Answer:_______________
1.2     The type of reproduction in which the young develop from the eggs that are kept in the mother’s body but
        did not receive nutrients from the mother
        A       Vivipary
        B       Ovipary
        C       Ovovivipary
        D       Altricial
        Answer:_______________
1.3     Which one of the following is the characteristic of an external fertilization?
        A       Copulation takes place
        B       A large number of eggs are produced
        C       The embryo is protected in the female body
        D       Sperms are introduced into the body of a female
        Answer:_______________
1.4     The type of reproduction in a seahorse where a female deposits her eggs into a poch and a male
        secretes its sperm in the pouch. Fertilization and the development of the fertilized egg takes place
        in the pouch
        A       External fertilization and Vivipary
        B       Internal fertilization and Vivipary
        C       External fertilization and Ovipary
        D       Internal fertilization and Ovipary

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        Answer:_______________

1.5     A young one moves around in search of food immediately after hatching. This is an example of:
        A       Vivipary
        B       Ovovivipary
        C       Altricial development
        D       Precocial development
        Answer:_______________
Question 2
Supply the correct biological term for each of the following descriptions
2.1     The type of fertilization associated with ovovivipory
        Answer:_______________
2.2     The reproductive strategy involving the laying of eggs
        Answer:_______________
2.3     The reproductive strategy where hatchings are able to move and feed themselves
        Answer:_______________
2.4     Type of fertilization where the nucleus of a sperm fuses with the nucleus of an egg outside the body
        of a female
        Answer:_______________
2.5     A reproductive strategy in humans where the foetus develops in the uterus
        Answer:_______________
Question 3
Indicate whether each of the statement in COLUMN1 applies to A only, B only,
Both A and B or None of the items in COLUMN 11. Write A only, B only, Both A and B or None next to the
question number.
NB: Learners have a tendency of writing A, B or A and B. This is not allowed

                     COLUMN 1                             COLUMN 11             ANSWER
 3.1    Eggs incubated in nests                          A Ovipary           ______________
                                                         B Ovovivipary
 3.2    Young arise from hatching the mother’s body      A Ovipary           ______________
                                                         B Vivipary
 3.3    Gestation period requested                       A Ovipary           ______________
                                                         B Vivipary
 3.4    Serves as a source of nutrition                  A Amnion            ______________
                                                         B Yolk sac

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4       Read the passage below.
        REPRODUCTIVE STRATEGY IN KANGAROOS
        The red kangaroo reproduces by sexual reproduction. After mating, the
        fertilised egg undergoes gestation in the uterus. After 33 days of gestation,
        the red kangaroo gives birth to an offspring that is hairless, blind and only a
        few centimetres long.

        The offspring moves from the vagina by following a trail of saliva secreted by
        the mother to a protective pouch where it remains for a year. During this time
        the offspring drinks milk from the mother who has teats in her pouch.

        After 190 days it leaves the pouch.

        4.1     State whether:

                (a)   Fertilisation in the red kangaroo species is INTERNAL or EXTERNAL
                                                             (1)
                      __________________________________________
                (b)   The red kangaroo species is OVIPAROUS, OVOVIVIPAROUS or VIVIPAROUS
                                                                     (1)
                __________________________________________________________

        4.2      Give a reason for your answer to QUESTION 2.5.1(b).                      (1)
                __________________________________________________________

        4.3      State TWO ways in which the survival of the offspring immediately
                 after birth is ensured in the red kangaroo species.               (2)
                ___________________________________________________________

HUMAN REPRODUCTION

Master biological terms
Identify different parts in the diagrams
Be able to label and give function(s) of each label

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TERMINOLOGY
     TERM                                        DESCRIPTION
 Acrosome         Structure ia a sperm that ciontains enzymes used to penetrate an egg
 Amnoic fluid     Liquid surrounding the human embryo
 Blastocyst       Hollow ball of cells into which fertilized egg develops
 Chorion          Membrane with finger-like projections that grow into the uterine wall
 Endometrium      Uterine lining that is richly supplied with blood vessels
 Gametogenesis    Formation of gametes
 Implantation     Process by which an embryo attaches to the uterine wall
 Menstruation     Breaking of uterine wall that is accompanied by flow of blood
 Oogenesis        Formation of an ovum by meiosis in females
 Ovulation        Release of an ovum from the ovary
 Placenta         Embryonic and maternal tissue responsible for nutrition, gaseous
                  exchange and excretion
 Puberty          Stage in males and females where sexual maturity is reached
 Spermatogenesis Formation of sperms by meiosis in males
 Umbilical cord   Hollow tube attaching an embryo to the placenta
 Umbilical artery Blood vessel carrying wastes from the foetus to the placenta
 Umbilical vein   Blood vessel carrying oxygenated blood from the placenta to a foetus

5       Supply the correct biological term for each of the following descriptions
                              DESCRIPTION                                             TERM
1. Structure in the sperm cell that contains enzymes used to penetrate the
ovum
2. The liquid that surrounds the human embryo                                Amniotic fluid
3. A hollow ball of cells into which the fertilised ovum develops            B
4. Specialised cells found between the seminiferous tubules that produce     Cells o
the hormone testosterone
5. The membrane that forms finger-like projections which grow into the       C
uterine wall
6.The lining of the uterus which is richly supplied with blood vessels
7. Coiled tubular structure outside the testis that stores sperms.
8. The part of the female reproductive system in which fertilisation takes   Fallopian tube
place
9. The name given to the embryo after it reaches 12 weeks                    Foetus
10. The hormone produced by the pituitary which controls growth of the
Graafian follicle
11. The formation of gametes by meiosis.
12. Layer within the ovary that is responsible for formation of ova
through meiosis
13. Another name for the period of pregnancy                                 Gestation
14. The process by which the embryo becomes attached to the uterine          Implantation
wall
15. The hormone which converts the ruptured follicle into a corpus           L
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luteum
16.Type of cell division by which sperms are produced                        Meiosis
17. The 28-day reproductive cycle in females involving changes in the
ovary and uterus
18. Tearing away of the endometrium lining of the uterine wall,              Menstruation
accompanied by the loss of blood
19. The cell division by which the zygote becomes multicellular              Mitosis
20. Production of ova by meiosis
21. The hormone which starts the preparation of the lining of the uterus     Oestrogen
for attachment of the fertilised ovum
22 Process by which an ovum is released from the ovary in humans             Ovulation
23. Gland in the brain that produces FSH and LH
24. Combination of foetal and maternal tissue responsible for gas            Placenta
exchange, nutrition and excretion
25. Hormone that maintains pregnancy                                         Progesterone
26. The stage when sexual maturity is reached in males and females           Puberty
27. Specialised cells inside the seminiferous tubules which play a role in   Cells
nutrition
28. Production of spermatozoa by meiosis                                     Spermatogens
29. Hormone responsible for secondary sexual characteristics in males        Testosterone
30. A hollow, rope-like tube which attaches the embryo to the placenta       Umbilical Cord
31. The blood vessel that carries nitrogenous waste from the foetus to the   Umbilical atery
placenta
32. The blood vessel that carries oxygenated blood from the placenta to      Umbilical vein
the foetus

6.      Study the diagram below and answer the questions that follow.

        6.1     Provide labels for A, B, E and G.                                           (4)
                 __________________________________________
                 __________________________________________
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                      __________________________________________
                      __________________________________________
       6.2         State ONE function of each for parts C and F, respectively. (2)
                      ________________________________________________
                     _________________________________________________

          6.3       State the LETTER and NAME of the part where sperms are produced.            (1)
                      ________________________________________________

           6.4       Explain why it is necessary for part D to 'hang outside' the body of the
                      Male     .                                                              (3)
                       ___________________________________________________________
                       ___________________________________________________________
                       ___________________________________________________________

             6.5      Name the following:
                      (a) The cells that secrete a male sex hormone                             (1)
                          ____________________________________________________

                     (b)   The hormone that stimulates the development of secondary sexual
                           characteristics in males                                        (1)
                           _____________________________________________________

          6.6 During a vasectomy, part B is surgically cut.

                    Explain how this procedure will act as a method of contraception. (2)
                    ___________________________________________________________
                    ___________________________________________________________

             6.7      Will it be possible for a man who is HIV positive to pass the HI virus to
                           another person after he undergoes a vasectomy?                       (1)
                    ____________________________________________________________

          6.8        Explain your answer to QUESTION 6.7.                       (2)
                      _________________________________________________________
                     __________________________________________________________

.

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7 Study the diagrams below showing the male and female reproductive systems.

        7.1     Identify parts A, B and F respectively.                               (3)
                ___________________________________________________________
                ___________________________________________________________
                ____________________________________________________________
        7.2     State ONE function of each of the following:
                (a)    The fluid produced by part C                          (1)
                       _____________________________________________________
                       _____________________________________________________

                (b)    Part E                                                 (1)
                        ______________________________________________________
                       _______________________________________________________

        7.3     Fertilisation usually takes place at F. Why will a blockage at F...
                (a)    Prevent fertilisation?                                 (1)
                        _____________________________________________________
                       ______________________________________________________

                (b)    Not necessarily lead to infertility?                   (2)
                       ______________________________________________________
                       ______________________________________________________

        7.4     Give the LETTER and NAME of:

                (a)    The part where the zygote will be formed               (2)
                       ______________________________________________________

                (b)    The part where the Graafian follicles develop                  (2)
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                          ______________________________________________________

                (c)        The part that plays a role during copulation          (2)
                          ______________________________________________________

       7.5      Give the LETTER ONLY of the organ where meiosis takes place in the:
                         (a)   Male reproductive system                                    (1)
                               _______________________________________________

                         (b)   Female reproductive system                         (1)
                               __________________________________________________

        7.6           Name the type of gametogenesis that takes place in the:
                  (a)     Male reproductive system                                                (1)
                          _____________________________________________________

                  (b)     Female reproductive system                                              (1)
                          ______________________________________________________

         7.7          State TWO functions of part H.
                      _______________________________________________________
                      _______________________________________________________                    (2)

       7.8            Explain why it is necessary for part D to be 'outside' the body in
                      males.
                                                                                                 (2)

8.      Study the following diagram showing the sequence of events of the development
        of an ovum in a 28-day cycle.

                                                                            D

                                                                                A
        1

        8.1 Identify the:
                  (a) Follicle labelled A                               B

                          ____________________________________________________
                                                    C
                  (b) Structure labelled C
                          ____________________________________________________
                  (c) Name the process shown at B
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                        ____________________________________________________
                 (d) Hormone responsible for the formation of part A
                        ____________________________________________________
                 (e) Hormone responsible for the formation of part C
                        ____________________________________________________                  (5)
        8.2     What type of cell division resulted in the formation of part D?               (1)
                        _____________________________________________________
        8.3     If the events shown above took place in a 28-day cycle, state whether
                fertilisation took place during this period.                          (1)
                ___________________________________________________________

        8.4     Explain your answer for QUESTION 3.3.                                         (3)
                ____________________________________________________________
        8.5     Explain HOW and WHY the production of FSH is inhibited when fertilization takes place.
                                                                       (4)
                ____________________________________________________________
                _____________________________________________________________

9.       Study the graph below which shows the menstrual cycle and the influence
         of the different hormones on it.

                   Pituitary/
                                                       LH
                   hypophysis              FSH
                   hormone

                   levels

                  Growth of
                  follicle

                                         oestrogen                                 progesterone
                   Ovarian
                   hormone
                   levels

                   Thickness of
                   uterinelining/
                   Endometrium

                                     0          7             14          21           28
                                    28
                                                          Days
                            Hormonal regulation of the female reproductive cycle

       9.1 On which day does ovulation take place?                                            (1)
                ____________________________________________________________
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       9.2      Between which days does menstruation take place?                              (1)
                  _____________________________________________________________
       9.3      State any ONE function of Luteinising Hormone (LH).             (1)
                   ____________________________________________________________
                  _____________________________________________________________

       9.4    Describe the changes in the level of LH shown in the graph.                     (2)
           ____________________________________________________________
       9.5       Describe the relationship between the level of oestrogen and the
                 endometrium from day 7 to day 14.                                            (3)
                 _________________________________________________________
                 __________________________________________________________
                 __________________________________________________________

        9.6      Explain why it is necessary for the level of progesterone in the blood to
                 increase after ovulation.                                                 (3)
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________

         9.7     Did fertilisation take place in the 28-day cycle illustrated in the graph?   (1)
                 _____________________________________________________________
          9.8     Explain your answer to QUESTION 9.7.                                        (2)
                  ____________________________________________________________
                  ____________________________________________________________
                  ____________________________________________________________
10.     The diagram below shows part of the female reproductive system. Structures
        B to G and processes 1, 2 and 3, occurring in the Fallopian tube and uterus,
        are magnified.

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            10.1          Label C and D.                                        (2)
                          _____________________________________________________
                          _____________________________________________________

            10.2          State which processes are taking place at 1, 2 and 3 respectively? (3)
                          _____________________________________________________

                          _____________________________________________________

                          _____________________________________________________

                10.3      State how many chromosomes are present in the following structures:

                         (a)    E                                                (1)
                          ______________________________________________________

                          (b)    Each cell of structure G                                    (1)
                          ______________________________________________________
                    10.4 Draw an enlarged labelled diagram of structure F to show its details.(5)

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                 10.5 State two functions of fluid A.                        (2)
                      ______________________________________________________

                  10.6 Structure B transports substances to and from the foetus.
                       (a)   Name one useful substance transported to the foetus. (1)
                       ______________________________________________________

                       (b)    Name one waste product transported from the foetus.        (1)
                       _______________________________________________________

11     Study the diagram below and answer the questions that follow.

                                                             A
                                                             B
                                                             C
                                                             D
                                                             E

                                                             F

     Match structures (A to F) with the descriptions (11.1 to 11.5) below, for
     example 11.6 G. A letter may be used more than once, or not at all.

     11.1   Where gaseous exchange occurs between the mother and the foetus        _________
     11.2   Removes excretory products from the foetus                             _________
     11.3   Contains strong muscles which will push the foetus out during birth    _________
     11.4 Clamped and cut after the baby is born                                   _________
     11.5 Acts as a shock absorber for the developing foetus.                      _________
                                                                    (5)

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 MEIOSIS

 TERMINOLOGY

     TERM                                       DESCRIPTION
 Anaphase 1        Phase of meiosis in which CHROMOSOMES are pulled to the
                   opposite poles
 Anaphase 11       Phase of meiosis in which CHROMATIDS are pulled to the opposite
                   poles
 Bivalent          A pair of homologous chromosomes that are involved in crossing over
 Centrioles        Structures that form spindle fibres during meiosis
 Centromere        Structure in a chromosome that holds chromatids together
 Centrosome        A structure that divides to form two centrioles in an animal cell
 Chiasma           Point of attachment of two chromatids during crossing over
 Chromatids        Two strands that form a chromosome
 Crossing over     Process where there is an exchange of genetic material between the
                   chromatids of homologous chromosomes
 Cytokinesis       Division of the nucleus resulting in a cell having half the number of
                   chromosomes
 Diploid           A condition in a cell where there is a two sets of chromosomes
 DNA replication   Process where DNA molecule makes an exact copy of itself
 Disjunction       Separation of chromosomes or chromatids during Anaphase
 Down Syndrome     Genetic disorder that is caused by an extra copy of chromosome 21
 Karyokinesis      Division of the cytoplasm
 Haploid           A condition in a cell where there is a single set of chromosomes
 Homologous        Chromosomes that are similar in shape and code for the same
 chromosomes       characteristics
 Interphase        A phase during which DNA replication occurs
 Metaphase 1       Phase in meiosis where chromosomes lie along the equator in pairs
 Metaohase 11      Phase in meiosis where single chromosomes lie along the equator
 Non-disjunction   Failure of chromosomes or chromatids to separate during meiosis
 Prophase 1        Phase of meiosis during which crossing over occurs
 Spindle threads   Structure in meiosis to which chromosomes or chromatids attach
 Telophase 1       Phase in meiosis in which two cells having half the number of
                   chromosomes are formed
 Telophase 11      Phase in meiosis in which four cells having half the chromosome
                   compliment as the original cell are formed

 For more information in meiosis refer paper 11 in this document

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 ANIMAL RESPONSE TO THE ENVIRONMENT

 NERVOUS SYSTEM, AN EYE AND AN EAR

 NOTES
 Learners must be able to identify different parts of nervous sysrem
 Be able to label and give functions of different parts
 Apply the gained knowledge to a practical situation
 Be able to interpret the graphs related to this topic
 Examples of some usual body responses to some stimuli must be made

NEURONS, BRAIN AND REFLEX ARC
12      Study the diagram below and answer the questions that follow.

        12.1     Name the type of the neuron presented in the diagram           (1)
                 ___________________________________________________
        12.2     List all the structural details that you could identify in 2   (3)
                 ___________________________________________________
                 ___________________________________________________
                 ___________________________________________________
        12.3        Give the labels for parts numbered 5, 6, 7, and 9           (4)
                 ___________________________________________________
                 ___________________________________________________
                 ___________________________________________________
                 ___________________________________________________

        12.4     Give the functions of the parts labelled 1, 5, 7, and 9        (4)
                __________________________________________________________
                __________________________________________________________
                __________________________________________________________

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                __________________________________________________________

13      Study the diagram below and answer the questions that follow.

        13.1     Write down only the letter (A–D) of the part which:
                 (a)    Controls heartbeat                               ______________

                 (b)    Contains the centres that control balance, muscle tone                        and
                        equilibrium                                  ______________

                 (a)    Has centres that interpret what you see          ______________

                 (b)    Coordinates voluntary muscle movements           ______________

                 (e)    Has grey matter on the inside and white matter                                      on
                        the outside                                 ___________
                                                                                  (5)

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14.     Study the diagram below and answer the questions that follow.

      14.1      Identify and give TWO functions of the structures labelled A, D, and E
                ________________________________________________________
                ________________________________________________________
                ________________________________________________________
                ________________________________________________________
                ________________________________________________________
                ________________________________________________________
                ________________________________________________________
                                                (3 X 3)     (9)
      14.2      Name the part of the brain that is responsible for:
                (a)     Relaying incoming messages to the correct parts of the brain
                ________________________________________________________                 (1)
                (b)     Controlling the dilation and constriction of blood vessels
                ________________________________________________________                 (1)

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15.    Study the diagram and answer the questions that follow.

        15.1   Identify the neurons marked A and B.
        _______________________________________________________
              _______________________________________________________                  (2)

        15.2     Write the LETTER and NAME of the structure that is stimulated by the hammer.
                ______        ___________________________________________               (2)

        15.3     Explain what would happen if part C is severely damaged               (2)
                ________________________________________________________
                ________________________________________________________
                ________________________________________________________

        15.4    Give TWO examples of reflex actions other than the knee-jerk in humans. (2)
                ________________________________________________________
                ________________________________________________________

        15.5     Why are reflex actions important to the human body?                    (2)
                ________________________________________________________
                ________________________________________________________

          15.6 Differentiate between a reflex arc and a reflex action.                  (2)
               ________________________________________________________
               ________________________________________________________

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16.     Study the diagram below which shows the human brain, spinal cord and the right leg.

        16.1     Identify the parts labeled A, B, C, D and F                                (5)
                _________________________________________________________
                _________________________________________________________
                _________________________________________________________
                _________________________________________________________
                _________________________________________________________

        16.2     What will be the effect on the body if part B is damaged?                  (2)
                _________________________________________________________
                _________________________________________________________

        16.3     Give the LETTER of the part that secretes the hormone TSH                  (1)
                _________

        16.4    Give the letter of the part that coordinates the movement of the legs under
                normal circumstances.                                                       (1)
                __________

        16.5    Draw and label the type of neuron as indicated by E.                        (7)

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        16.6      Explain the reflex action shown in the diagram.                    (5)
                 _______________________________________________________
                 _______________________________________________________
                 _______________________________________________________
                 _______________________________________________________
                 _______________________________________________________

        16.7     Explain the significance of reflex actions in humans.               (2)
                 _______________________________________________________
                 _______________________________________________________

17.     Study the following diagram and answer the questions that follow.

                17.1   Write the LETTER and the NAME of each of the following:
                       (i)   Liquid that helps maintain the shape of the cornea      (2)
                       _____        ___________________________________

                       (ii)  Region where the clearest image is formed               (2)
                       _____       ___________________________________

                       (iii) Part responsible for the colour of the eye              (2)
                       _____         __________________________________

                       (iv)  Layer that contains blood vessels and a brown pigment   (2)
                       _____        __________________________________

                       (v)   Accommodation                                           (6)
                       _____       __________________________________
                       _____       __________________________________
                       _____       __________________________________
                       (vi)  Refraction of light rays                                (2)
                       _____       __________________________________
                       _____       __________________________________
                       (vii) Conversion of light stimuli into impulses               (1)
                       _____       __________________________________

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17.2            Explain the role of part B in bright light conditions         (4)
                _______________________________________________
                _______________________________________________
                _______________________________________________
                _______________________________________________

18.     Study Diagrams I and II that illustrate the lens and parts of one layer of
        the human eye, as well as the graph below and answer the questions
        that follow.

                 18.1   Identify parts A and B.                                      (2)
                 _______________________________________________________
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                _______________________________________________________

                18.2 Which Diagram (I or II) shows part of the eye
                (i)   where the radial muscles are contracted.                         (1)
                ________________________________________________________

                (ii)  under dim light conditions.                                      (1)
                ________________________________________________________

                18.3 Explain your answer in QUESTION 18.2 (i).                         (2)
                ________________________________________________________

                18.4   Which LETTER from the graph that indicates each of the following:

                (i)   The eye looking at a nearby stationary object                    (1)
                _______

                (ii)  The eye looking at an object moving towards the viewer           (1)
                _______

                18.5 Explain the significance of the elastic nature of the lens.       (2)
                _________________________________________________________
                _________________________________________________________

19.     Study the following diagrams showing visual defects and answer the
        questions that follow.

                19.1   Which diagram (A or B) illustrates…
                (a)    Short-sightedness                                               (1)
                       _________

                (b)    Long –sightedness                                               (1)
                       _________
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                19.2   Compare short-sightedness and long-sightedness by completing the
                       table below.

                                               Short-sightedness    Long –sightedness
                 Shape of eyeball              (a)                  (b)
                 Focal point on retina for     (c)                  (d)
                 nearby objects
                 Corrective type of lens       (e)                  (f)
                 Corrective corneal laser      (g)                  (h)
                 surgery

                19.3   Explain the nature and treatment of the following:

                (a)     Astigmatism and                                       (4)
                       ______________________________________________________
                       ______________________________________________________
                       ______________________________________________________

                (b)     Cataracts                                                         (2)
                       ______________________________________________________
                       ______________________________________________________
                       ______________________________________________________

20.     Jabu took part in an experiment on the eye's response to light. A lamp was
        placed at seven positions from Jabu's face. The diameter of Jabu's pupil was
        measured at each position.

        The results are shown in the table below.

                POSITION OF THE              DIAMETER OF THE
                LAMP                         PUPIL (mm)
                        1                              1,2
                        2                              1,8
                        3                              2,4
                        4                              3,0
                        5                              3,6
                        6                              4,2
                        7                              4,8

       20.1     (a)   At which position was the lamp furthest from the eye?               (1)
                __________________________________________________________

                (b)   Explain your answer to QUESTION 9.1(a).                             (2)
                __________________________________________________________
                __________________________________________________________

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Life Sciences                            SADTU                                        Revision document

        20.2     When the lamp was moved from position 1 to position 2, describe
                 the mechanism that caused the change in the diameter of the pupil.   (4)
                ____________________________________________________________
                ____________________________________________________________
                ____________________________________________________________
                ____________________________________________________________

21.     Study the diagram below showing a longitudinal section through an eye.

        21.1     Label parts 2, 3, 4 and 5 respectively.                              (4)
                 ________________________________________________________
                 ________________________________________________________
                 ________________________________________________________
                 ________________________________________________________

        21.2     Name and describe the process that causes part 1 to dilate.          (6)
                 ________________________________________________________
                 ________________________________________________________
                 ________________________________________________________
                 ________________________________________________________

        21.3     State how the following defects can be treated to improve vision:
                 (a)     Long-sightedness
                 ________________________________________________________

                 (b)   Astigmatism
                 ________________________________________________________
                 (c)   Cataracts
                 ________________________________________________________

                 (d)   Short-sightedness
                 ________________________________________________________             (4)

                                                        26
Life Sciences                           SADTU                                            Revision document

22.     Study the diagram and answer the questions that follow.

        22.1    Part B secretes a wax known as cerumen. Sometimes the wax forms a solid plug against part C.

                (i)   State TWO functions of cerumen.                                     (2)
                __________________________________________________________
                __________________________________________________________

                (i)   Explain the effect on hearing if a waxy plug is formed against               part C.
                                                                           (3)
                __________________________________________________________
                __________________________________________________________
                __________________________________________________________

        22.2    (i)    Will the sound waves reach part D if part L was removed?           (1)
                __________________________________________________________
                (ii)  Give a reason for your answer.                                      (2)
                __________________________________________________________

        22.3    Name the part of the brain to which nerve H will conduct a nerve impulses and give a reason for
                your answer.                                        (3)
                ___________________________________________________________
                ___________________________________________________________
                ___________________________________________________________

        22.4           Give the LETTER of the label that answers the following statements:

                (a)    Sets perilymph of the inner ear into motion                       ___
                (b)    Converts sound waves into nerve impulse                           ___
                (c)    Equalises pressure on either side of the tympanic membrane        ___
                                                        27
Life Sciences                            SADTU                                             Revision document

                  (d)   Collects and directs sound waves into the auditory canal           ___
                  (e)   Increase the intensity and amplification                           ___
                  (f)   Perception of the head movements                                   ___
                  (g)   Absorbs extra pressure sets up in the inner ear                    ___
                  (h)   Contains the organ of Corti                                ___
                                                                      (8)

          22.5 Predict what would happen if the sacculus and utriculus are damaged.        (2)
                ____________________________________________________________

           22.6     In severe cases when the middle ear becomes filled with thick mucus,
                    surgeons place a tube called ‘grommet’ in the membrane ‘F’ to drain
                    the mucus and also to reduce pressure in the middle eye. Once the
                    grommet is in place, the child should not go swimming.

                    Explain why a child should not go swimming                             (5)
                __________________________________________________________
                __________________________________________________________
                __________________________________________________________
                __________________________________________________________

         22.7 What is the significance of the position of the structures labelled ‘I’?
              Explain the significance of ‘I’.                                             (8)
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________
              _________________________________________________________

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Life Sciences                            SADTU                                               Revision document

ENDOCRINE SYSTEM

23.     Read the following passage and answer the questions that follow.

                    ‘Messenger’ substances are produced in endocrine glands of the human
                    body and then transported to other parts of the body where they are
                    involved in regulating the activity of particular parts. Slow, sustained or
                    ongoing responses to these substances complement or support the other
                    more rapid and short-lived responses of the body.

        23.1 Write a scientific name for each of the following phrases taken from the passage:

                (a) Messenger substances                                                     (1)
                _________________________________________________________

                (b) Particular parts whose activities are regulated                          (1)
                _________________________________________________________

        23.2    Complete the following table by writing the numbers 1 .2.1 to 1.2.9 in your
                answer book and next to each number the correct missing information.

         Gland            Position in the Hormone                  Function of hormone
                          body
         1.2.1            1.2.2                                    1.2.3
         ___________      ______________ Growth hormone            ________________________
                                                                   ________________________

         1.2.4                                1.2.5                1.2.6
         ___________      Below the larynx    _____________        ________________________
                                                                   ________________________

         1.2.7            1.2.8               1.2.9                Prepares body for an
         ___________      _____________       _____________        emergency

                                                                      (9)

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Life Sciences                            SADTU                                              Revision document

24.     Study the diagram below and answer the questions that follow.

        24.1    Label the parts numbered 1 and 4.                                           (2)

        24.2    Write down only the NUMBER of the gland that:

                (a)   Produces the hormone glucagon                                 _____
                (b)   Produces a hormone that controls the growth of long bones     _____
                (c)   Produces an iodine-containing hormone                         _____
                (d)   Produces a hormone that is involved in the re-absorption of
                      some salts by the kidneys                                     ____
                                                                     (4)

        24.3    State TWO similarities between hormones and nerves with regard                      to their
                functions.                                                     (2)
                __________________________________________________________
                __________________________________________________________
                __________________________________________________________

        24.4    State ONE functional difference between hormones and motor nerves.          (2)
                __________________________________________________________

        24.5    All endocrine glands have a large number of blood capillaries close to the cells.
                Give an explanation for this feature.                                       (2)
                ___________________________________________________________
                ___________________________________________________________

        24.6    Mention TWO hormones secreted by D and their functions      (4)
                ___________________________________________________________
                ___________________________________________________________

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Life Sciences                           SADTU                                              Revision document

        24.7    Explain what is meant by ‘feedback mechanism’ by referring to structures            1 and 2
                                                                                  (7)
                ___________________________________________________________

                ___________________________________________________________

                ___________________________________________________________

                __________________________________________________________

                __________________________________________________________

                __________________________________________________________

                __________________________________________________________

25.     Study the diagram below and answer the questions that follow.

        25.1    Give labels for the glands numbered 1 and 2.                               (2)
                __________________________________________________________

                __________________________________________________________

        25.2     Name hormone A.                                                           (1)
                __________________________________________________________

        25.3    Describe the negative feedback mechanism that operates when the thyroxin level in the
                blood is too high, as indicated by process C.                          (4)
                __________________________________________________________

                __________________________________________________________

                __________________________________________________________

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Life Sciences                           SADTU                                           Revision document

26.     Choose an item from COLUMN II that matches a description in COLUMN I. Write only the
        letter (A to H) next to the question number (26.1 to 26.5) e.g. 26.6 J.

                COLUMN I                              COLUMN II
                26.1 The hormone which stimulates the A growth hormone
                    mammary glands to secrete milk.
                         ___________                  B oestrogen

                                                               C osmoregulation
                26.2 Control of water balance by the
                    hormone ADH                                D insulin
                           ____________
                                                               E glycogen

                26.3 Hormone responsible for secondary         F prolactin
                     sexual characteristics in males
                                                               G glucagon
                            ____________
                                                               H testosterone
                26.4 Hormone that controls normal growth
                    and development
                            _____________

                26.5 Pancreatic secretion that increases the
                    blood sugar level
                           ______________

                                                                                  (5x1) (5)

                                                       32
Life Sciences                            SADTU                                            Revision document

    27 The graph below illustrates the level of the blood sugar of a healthy person. Study the
       graph and answer the questions that follow.

        27.1    At what time of the day is the level of blood sugar:
                (a)    The highest?                           __________________
                (b)    The lowest?                            __________________          (2)

        27.2    During which hour was the rate of increase in the level of blood sugar:
                (a)    The greatest?                          __________________
                (b)    The least?                             __________________          (2)
        27.3    Which hormone is responsible for the decrease in blood sugar level at
                points 1, 2, and 3?                                                       (1)
                ________________________________________________________

        27.4    In which organ (gland) is this hormone produced?                          (1)
                ________________________________________________________
        27.5    At point B a meal of fish and chips was eaten. Explain why there was a rise in blood
                sugar level and therefore a rise in hormone level?                        (5)
                _________________________________________________________
                _________________________________________________________
                _________________________________________________________
                _________________________________________________________
                _________________________________________________________

        27.6    If a person is unable to produce this hormone explain how this will
                affect the blood glucose level after a meal of pasta?                     (2)
                _______________________________________________________

                ________________________________________________________

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Life Sciences                               SADTU                                             Revision document

28.        Provide the correct biological term for each of the following descriptions in
           the space provided.
                                      Description                                          Term

      1.        Glands that pour their secretions directly into the blood stream

      2.       Patches of specialised cells within the pancreas that produce
            insulin and glucagon.

      3.    A gland that functions both as an endocrine and an exocrine gland

      4.   Part of the brain to which the hypophysis is attached

      5.    A hormone which stimulates secretion of the thyroid gland.

      6. Interaction between TWO endocrine glands, where a change in the
      hormonal production level of one, is referred back to it, resulting in an
      opposite response

      7.   Hormone that promotes absorption of glucose into cells

      8.   Hormone that increases heart beat and blood pressure in
             emergency situations

      9.   Pancreatic secretion that increases the blood sugar level

      10. Hormone that controls normal growth and development

      11. Hormone responsible for secondary sexual characteristics in males

      12. Hormone that controls metabolism

      13. Gland that produces FSH and LH

      14. Hormone produced by the corpus luteum

      15. Hormone produced by the Graafian follicle

      16. Control of water balance by the hormone ADH

      17. Organ on which the adrenal glands are located

      18. The hormone which stimulates the mammary glands to secrete
      milk.

                                                             34
Life Sciences                             SADTU                                        Revision document

HOMEOSTASIS

29.     Study the diagrams below of sections through the skin and
        answer the questions that follow

         29.1     Which diagram, A or B, indicates a greater blood flow to the skin?          (1)
                  ________________________________________________________
         29.2    Give ONE reason for your answer.                                             (2)
                 _________________________________________________________
                 _________________________________________________________
         20.3    Which diagram, A or B, represents the skin losing more heat to the
               external environment?                                                          (1)
                _________________________________________________________
         29.4 Explain how the formation of sweat will results in heat lost.                   (3)
                 __________________________________________________________
                ___________________________________________________________
                ___________________________________________________________
                ___________________________________________________________

30      Study the diagram and answer the questions that follow.

        30.1    Identify parts A and C.                                                       (2)
                ______________________________________________________________

                ______________________________________________________________

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Life Sciences                            SADTU                                            Revision document

        30.2    What change will part B undergo if the environmental temperature
                suddenly rises?                                                                  (1)
                ____________________________________________________________

        30.3    Explain the advantage of the change named in QUESTION 2.2                        (4)
                ____________________________________________________________

                ____________________________________________________________

                ____________________________________________________________

                ____________________________________________________________

        30.4    (i)     Give the name of the hormone that will have the opposite
                        effect on part B to that of a rise in the environmental
                         temperature.                                                             (1)
                        _______________________________________________________

                (ii)    Under what conditions will the hormone named in
                        QUESTION 30.4 (i) be secreted?                                           (1)

                (iii)   Explain the significance of the effect on part B of the hormone
                        named in QUESTION 30.4 (i).                                              (5)
                        ______________________________________________________

                        ______________________________________________________

                        ______________________________________________________

                (iv)    What effect will the hormone named in QUESTION 30.4 (i) have
                        on the activity of the thyroid gland?                                            (1)
                        _______________________________________________________

                        _______________________________________________________

                (v)     Explain your answer in QUESTION 30.4 (iv).                                       (2)
                        ____________________________________________________

                        ____________________________________________________

                                                         36
Life Sciences                           SADTU                                             Revision document

    31 The graph below shows the effect of strenuous exercise, followed by a cold shower, on
       the body temperature of an athlete.

                                Diagram 1           Diagram 2

        31.1    Which part of the brain responds to the temperature changes that occur at A and B
                on the graph?                                                                     (1)
                ______________________________________________________________

        31.2    What was the maximum temperature reached?                                         (1)
                ______________________________________________________________

        31.3    For what period of time did the person engage in strenuous exercise?              (1)
                ______________________________________________________________

        31.4    Why should body temperature not be allowed to fluctuate too much?                 (1)
                ______________________________________________________________

        31.5    Which diagram (I or 2) would represent the condition of the skin after 15 minutes (1)
                _______________________________________________________________

        31.6    Explain your answer to QUESTION 3.5                                               (2)
                _______________________________________________________________

                _______________________________________________________________

                                                        37
Life Sciences                           SADTU                                              Revision document

PLANT HORMONES

TERMINOLOGY

        TERM                                      DESCRIPTION
   Meristematic cell    Actively dividing cells found in the coleoptiles
   Coleoptile           A tip of a stem or root where meristematic cells are located
   Apical dominance     Inhibition of development of lateral buds by auxins present in them
   Tropism              Movement of part of a plant in response to a stimulus

    32 The following diagram shows an investigation that was carried out to determine
           the site of auxin production and its effect on growth and development in plants.

        32.1     Explain why the lateral buds in B, and not C, were able to develop into lateral
                branches                                                                           (2)
                __________________________________________________________________

                __________________________________________________________________

        32.2    State ONE possible deduction that can be made from the diagrams with regard
                 to the site where auxins are produced                                             (1)
                _______________________________________________________________

        32.3    What would happen if shoot B was illuminated from one side for a few days?         (2)
                _______________________________________________________________

                _______________________________________________________________

        32.4    Explain your answer to QUESTION 32.3                                               (2)
                _________________________________________________________

                _________________________________________________________

                _________________________________________________________

                                                        38
Life Sciences                               SADTU                                                  Revision document

33      In diagram I below, the growing point of a shoot is separated from the rest of the
         plant by a piece of plastic. It is then exposed to light from one side only.

        Diagram II below shows possible results.

       33.1     Which growth hormone is being investigated?                                               (1)
                __________________________________________________________

        33.2           (i) Which letter (A, B, C or D) from Diagram II, shows the
                           correct result expected after three or four days?                              (1)
                           ____________________________________________________

                       (ii) Explain your answer in QUESTION 33.2(i).                                      (3)
                           ____________________________________________________

                           ____________________________________________________

                           ____________________________________________________

        33.3    (i)        Filter paper is permeable to the hormone being investigated.
                           If the same experiment was repeated with a thin piece of filter
                           paper instead of a piece of plastic, which letter (A, B, C or D) from
                           Diagram II would then show the correct result?                                 (1)
                           _________________________________________________

                (ii)       Explain your answer in QUESTION 33.3(i).                                       (3)
                           ____________________________________________________

                           ____________________________________________________

                           ____________________________________________________

                                                             39
Life Sciences                          SADTU                                          Revision document

34.     The graph below shows the growth response of roots and shoots to auxins
        applied at different concentrations.

        34.1    At what concentration of auxins do shoots show the most growth?               (2)
                _______________________________________________________________

        34.2    At what concentration of auxins does growth begin to be inhibited in roots?   (2)
                ________________________________________________________________

        34.3    Name TWO places in plants where auxins are produced.                          (2)
                ________________________________________________________________

                ________________________________________________________________

        34.4    Explain the role of auxins in apical dominance                                (2)
                ___________________________________________________________

                ___________________________________________________________

                ___________________________________________________________

        34.5    Explain the role of

                (a)    Chemicals and                                                          (2)
                _________________________________________________________

                _________________________________________________________

                (b)    Thorns as plant defense mechanisms                                     (2)
                _____________________________________________________

                _____________________________________________________

                                                       40
Life Sciences                           SADTU                                            Revision document

35.     Stem tips were used in the experiment illustrated below. These experiments
        were conducted in the dark.

         35.1 What can you conclude from the resuls at X?                                       (2)
                _____________________________________________________________
                _____________________________________________________________
         35.2 Why was plain agar used on the stem tips in investigation Y?                      (2)
                _____________________________________________________________
                _____________________________________________________________
         35.3 What can you conclude from the results of investigation Y?                        (2)
                _____________________________________________________________
                _____________________________________________________________
         35.4 From the results of Z, what can you conclude about the effects of auxins
              on the stem tips.                                                                 (2)
                ___________________________________________________________________

                ___________________________________________________________________

                                                       41
Life Sciences                             SADTU                                              Revision document

36.       Study the diagram below and answer the questions that follow.

          36.1   What phenomenon is illustrated by the potted plant?                                  (2
                 _____________________________________________________
          36.2      Explain how this phenomenon is brought about.                                     (4)
                 __________________________________________________________
                 __________________________________________________________
          36.3    How does the phenomenon, mentioned in 36.1 have survival value for the plant? (2)

37.       An investigation was conducted to determine the effect of different
          concentrations of gibberellins on the average percentage and rate of seed
          germination in Penstemon digitalis (a garden plant).

          The following procedure was followed:

                Thirty seeds of P. digitalis were used.
                The seeds were divided into three groups of ten (groups A, B and C).
                The seeds in each group were soaked in different concentrations of
                 gibberellins for 24 hours, as shown in the table below:

                 GROUP CONCENTRATION OFGIBBERELLINS
                       (mg/ℓ)
                   A                   0
                   B                  500
                   C                 1000

         The seed mixtures were then filtered and rinsed under cold, distilledwater for 2 minutes.
         The three groups of seeds were then placed in a dark growth chamber
          at a temperature of 21,3 °C.
         Each day for 10 days, the groups of seeds were given the same
          amount of water.

          The seeds were observed each day. They were considered to have germinated as soon as
          the shoots and roots first appeared.

          The average percentage and rate of seed germination was calculated for each day.

                                                           42
Life Sciences                            SADTU                                              Revision document

        37.1    Identify the TWO dependent variables in the investigation above.                   (2)
                ___________________________________________________________-

                ___________________________________________________________

        37.2    State THREE factors not related to gibberellins that were kept constant in this
                investigation.                                                                     (3)
                ________________________________________________________

                ________________________________________________________

                ________________________________________________________

        37.3    State ONE factor that should have been kept constant with regard to the
                gibberellins during the investigation.                                             (1)
                ________________________________________________________

        37.4    Explain the advantage of including many seeds in each group of seeds.              (2)
                _____________________________________________________________

                _____________________________________________________________

        37.5    Explain why the seeds were left to germinate in a dark growth chamber.             (2)
                __________________________________________________________

                __________________________________________________________

                __________________________________________________________

                                                         43
Life Sciences                             SADTU                                              Revision document

HUMAN IMPACT ON THE ENVIRONMENT

    38                                                                                                           The
          table below shows the percentage of carbon dioxide(CO2) emitted by different
         sectors in a certain city in South Africa.

                                  CO2
                 SECTOR         EMISSION
                                  (%)
                Transport          25
                Residential        27
                Industrial         15
                Commercial         28
                Other               5             [Adapted from Energy scenarios for CTto-2050, 2011]
         38.1      Draw a pie chart to represent the data in the table above.
                 Show ALL calculations.                                                              (6)

         38.2       Which TWO sectors in the table above should NOT be included in the
                 determination of carbon emissions in a rural area?                                  (2)
                 ______________________________________________________________

                 ______________________________________________________________

         38.3         Explain how the planting of trees can assist in reducing the CO2 concentration
                  in the atmosphere.                                                                 (2)
                 ___________________________________________________________

                 ___________________________________________________________

         38.4        Describe how an increase in the CO2 concentration can lead to global warming. (3)
                 ____________________________________________________________

                 ____________________________________________________________

         39.     The carbon dioxide concentration in the atmosphere was recorded at 400 parts per
                 million (ppm) in May 2013 compared to 316 parts per million (ppm) in 1958. This
                 change is due to an increase in the use of fossil fuels as well as an increase in
                 deforestation.

         39.1     Describe how deforestation contributes to the high carbon dioxide
                 concentration in the atmosphere.                                                    (2)
                 _______________________________________________________________

                 _______________________________________________________________

         39.2    State ONE other impact of deforestation on the environment.                         (1)
                 ___________________________________________________________

         39.3    Explain why we should be concerned about the rising carbon dioxide levels.          (3)
                 ________________________________________________________________
                                                          44
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