KWAZULU NATAL PROVINCE LIFE SCIENCES - 2018 MATRIC INTERVENTION
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Life Sciences SADTU Revision document
KWAZULU NATAL PROVINCE
2018
MATRIC INTERVENTION
LIFE SCIENCES
1
Life Sciences SADTU Revision document
CURRICULUM GRADE 12
REVISION SUPPORT DOCUMENT
LIFE SCIENCES
2018
2
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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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)
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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 ___
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(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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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)
29Life 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)
___________________________________________________________
___________________________________________________________
30Life 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)
__________________________________________________________
__________________________________________________________
__________________________________________________________
31Life 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)
32Life 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)
_______________________________________________________
________________________________________________________
33Life 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.
34Life 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)
______________________________________________________________
______________________________________________________________
35Life 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)
____________________________________________________
____________________________________________________
36Life 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)
_______________________________________________________________
_______________________________________________________________
37Life 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)
_________________________________________________________
_________________________________________________________
_________________________________________________________
38Life 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)
____________________________________________________
____________________________________________________
____________________________________________________
39Life 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)
_____________________________________________________
_____________________________________________________
40Life 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)
___________________________________________________________________
___________________________________________________________________
41Life 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.
42Life 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)
__________________________________________________________
__________________________________________________________
__________________________________________________________
43Life 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)
________________________________________________________________
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