PRINCIPLES RELATED TO MARKING LIFE SCIENCES

1. If more information than marks allocated is given
   Stop marking when maximum marks are reached and put a wavy line and ‘max’ in the right-hand margin.
2. If, for example, three reasons are required and five are given
   Mark the first three irrespective of whether all or some are correct/incorrect.
3. If whole process is given when only a part of it is required
   Read all and credit the relevant part.
4. If comparisons are asked for, but descriptions are given
   Accept if the differences/similarities are clear.
5. If tabulation is required, but paragraphs are given
   Candidates will lose marks for not tabulating.
6. If diagrams are given with annotations when descriptions are required
   Candidates will lose marks.
7. If flow charts are given instead of descriptions
   Candidates will lose marks.
8. If sequence is muddled and links do not make sense Where sequence and links are correct, credit.
   Where sequence and links are incorrect, do not credit. If sequence and links become correct again, resume credit.
9. Non-recognised abbreviations
   Accept if first defined in answer. If not defined, do not credit the unrecognised abbreviation, but credit the rest of the answer if correct.
10. Wrong numbering
    If answer fits into the correct sequence of questions, but the wrong number is given, it is acceptable.
11. If language used changes the intended meaning
    Do not accept.
12. Spelling errors
    If recognisable, accept the answer, provided it does not mean something else in Life Sciences or if it is out of context.
13. If common names are given in terminology
    Accept, provided it was accepted at the national memo discussion meeting.
14. If only the letter is asked for, but only the name is given (and vice versa)
    Do not credit.
15. If units are not given in measurements
    Candidates will lose marks. Memorandum will allocate marks for units separately.
16. Be sensitive to the sense of an answer, which may be stated in a different way
17. Caption
    All illustrations (diagrams, graphs, tables, etc.) must have a caption.
18. Code-switching of official languages (terms and concepts)
    A single word or two that appear(s) in any official language other than the learner's assessment language used to the greatest extent in his/her answers should be credited, if it is correct.
    A marker that is proficient in the relevant official language should be consulted. This is applicable to all official languages.

QUESTIONS

SECTION A
QUESTION 1
1.1
1.1.1 A ✓✓
1.1.2 B ✓✓
1.1.3 C ✓✓
1.1.4 C ✓✓
1.1.5 B ✓✓
1.1.6 D ✓✓
1.1.7 A ✓✓
1.1.8 B ✓✓
1.1.9 A ✓✓
1.1.10 D ✓✓ (20 x 1) (20)
1.2
1.2.1 Sustainability ✓
1.2.2 Aldosterone ✓
1.2.3 Yolk sac ✓/yolk
1.2.4 Karyotype ✓
1.2.5 Cytokinesis ✓
1.2.6 Internal fertilisation ✓
1.2.7 Ovary ✓
1.2.8 Pesticides ✓
1.2.9 Chiasmata ✓/ Chiasma
1.2.10 Acrosome ✓ (10 x 1) (10)
1.3
1.3.1 B only ✓✓
1.3.2 A only ✓✓
1.3.3 None ✓✓ (6)
1.4
1.4.1

1. Vas deferens ✓ (1)
2. Urethra✓ (1)

1.4.2

• C ✓ Epididymis✓ (2)
• D ✓ Scrotum ✓ (2)

1.4.3

• Secrete a fluid ✓
• that stimulates the male gametes to be more mobile ✓ (2)

1.5
1.5.1 3 ✓ (1)
1.5.2 4 ✓ (1)
1.5.3 2 ✓ (1)
1.5.4 3 ✓ (1)
1.5.5 2 ✓ (1)
1.5.6 1 ✓ (1)
TOTAL SECTION A: 50

SECTION B
QUESTION 2
2.1
2.1.1

• Type of pollution that occurs when some industries release large quantities of hot water ✓
• into water bodies ✓ (rivers and oceans) (2)

2.1.2

• As a source of water ✓ for the informal settlement
• for household purposes/farming ✓ (2)

2.1.3

• Hot water contains less oxygen ✓ which will negatively affect other living organisms ✓
• Heating may lead to increased metabolic rate ✓which cause organisms to need more food and oxygen ✓
• Higher temperatures may encourage algal bloom ✓which may prevent sunlight from reaching photosynthesizing plants and they may die ✓
• Dead plants and animals will be decomposed ✓and decomposers will use up more oxygen ✓
• The decrease of oxygen and increase in decomposers ✓will reduce the quality of the water ✓
  (Mark first TWO only) (Any 2 x 2) (4)

2.2
2.2.1

• Burning of fossil fuels ✓
• Deforestation ✓ (2)

2.2.2

1. The heat rays from the sun that enter the Earth’s atmosphere are reflected back to space ✓ (1)
2. Most of the heat rays from the sun are trapped in the Earth’s atmosphere ✓ by greenhouse gases (1)

2.2.3

• More evaporation of water ✓which can lead to
• increased potential of flooding ✓ due to increased precipitation
  OR
• Rising sea levels due to melting ice in the glaciers✓/thermal expansion can lead to
• increased potential of flooding ✓
  OR
• Increased wildfires ✓ increasing the chances of soil erosion and
• eventually desertification ✓
  OR
• Increased droughts ✓ leading to
• food insecurity✓/ desertification
  (Mark first TWO only) (Any 2 x 2) (4)

2.3
2.3.1 Pituitary gland ✓ /Hypophysis (1)
2.3.2

• Gonadotropin-releasing hormone stimulates the pituitary gland ✓
• to release reproductive hormones ✓/FSH/ LH (2)

2.3.3

• FSH stimulates the development of a primary follicle ✓
•  into a Graafian follicle ✓ (2)

2.3.4

• The level of LH increases just before ovulation takes place ✓/High LH levels in the blood/urine indicate that ovulation is going to take place/an ovum will be released
• This indicates the period of highest fertility in females ✓ (2)

2.3.5

• The endometrium will not thicken enough ✓ and therefore causing the fertilised ovum not to implant ✓
• The endometrium will not be maintained ✓ and this could lead to a miscarriage ✓
  (Mark first ONE only) (Any 1 x 2) (2)

2.4 2.4.1 A group of conditions that cause the motor neurons in the nerves in the spine and brain to progressively lose function ✓ (1)
2.4.2

• Genetic issues ✓
• Viruses ✓
• Environmental issues ✓
  (Mark first TWO only) (Any 2) (2)

2.4.3

• The person would feel the pain ✓
• but would not be able to react ✓
• The motor neuron is not functioning, therefore the muscles would not be stimulated ✓ (3)

2.4.4

(4)
2.5
2.5.1 

• It is caused by an irregular curvature ✓
• of the front surface of the cornea ✓ (2)

2.5.2 Prescription lenses ✓ will be needed for clear vision (1)
2.5.3

• Short-sightedness/Myopia ✓
• Long-sightedness/Hypermetropia ✓
• Cataracts ✓
  (Mark first TWO only) (Any 2) (2) [40]

QUESTION 3
3.1 3.1.1

• To establish a baseline/starting point for the investigation from where the glucose levels will increase ✓✓
  OR
• To compare the change in the blood glucose levels to what it was before breakfast was eaten ✓✓ (2)

3.1.2 The type of breakfast ✓ /Low or high GI food (1) 3.1.3 8,0 ✓ – 8,2 mmol/ℓ (1)
3.1.4

• Low GI food causes a smaller increase in the blood glucose levels than high GI food ✓✓/ High GI food causes a larger increase in the blood glucose levels than low GI food
  OR
• Eating Low GI food causes the blood glucose levels to increase closer to normal after 120 minutes (4 mmol/ℓ to 5,2 mmol/ℓ) than high GI food (4 mmol/ℓ to 5,8 mmol/ℓ) ✓✓ (2)

3.1.5 Insulin ✓ (1)
3.1.6 

• A high GI breakfast causes a sharp increase in the blood glucose level ✓
• This will cause a large ✓/rapid increase in the blood insulin levels (2)

3.1.7

1. To improve reliability ✓ of the investigation (1)
2. To ensure the results were caused by the breakfast only ✓✓/ low and high GI food and not any other factor (2)

3.1.8

• Only females were used✓/same sex
• Females of the same age ✓/28–30 years old were used
• Same time intervals for measuring blood glucose concentration✓
  (Mark first TWO only) (Any 2) (2)

3.2 3.2.1 Geotropism ✓ (1)
3.2.2 

1.                        
   • As the plant was constantly rotating, there was an equal distribution of auxins throughout the stem ✓
   • therefore, there was no unequal growth of the stem ✓
   • And the stem continued to grow straight ✓ (3)
2.                              
   • As the plant was placed on its side, auxins accumulated at the lower side of the stem ✓
   • because of the gravitational force ✓
   • A high concentration of auxins on the lower side of the stem stimulated the growth of the stem ✓
   • Thus, unequal distribution of auxins caused unequal growth of the stem on the lower side ✓/the stem grew more on the lower side
   • causing the stem to bend/grow upwards ✓ (Any 4) (4)

3.2.3 To eliminate the effect of light ✓ on the growth movement of the stems / To prevent phototropism from influencing the results (1)
3.3 3.3.1

• Physical removal of the plants✓/mechanical methods/ example
• The use of herbicides ✓/chemical methods/example
• Using the natural enemies of the alien invasive species✓/biological control/example
  (Mark first THREE only) (3)

3.3.2

• Since alien plant invaders do not have natural enemies ✓
• they grow rapidly and outcompete the indigenous plants ✓leading to loss of biodiversity (2)

3.3.3

• Habitat destruction ✓ / any example
• Poaching ✓
  (Mark first TWO only) (2)

3.4 3.4.1

1. Auditory canal ✓/Meatus (1)
2. Semi-circular canals ✓ (1)
3. Cochlea ✓ (1)

3.4.2 E ✓ (1)
3.4.3 Sensory neuron ✓ (1)
3.4.4

• A change in speed or direction of movement ✓
• in any plane can be detected ✓
• in order to maintain balance ✓ (Any 2) (2)

3.4.5

• The tympanic membrane may rupture ✓
• The membrane will therefore not vibrate properly ✓
• and less vibrations will be transferred to the ossicles/oval window ✓
• The cochlea will be stimulated less ✓
• leading to hearing loss ✓ (Any 3) (3) [40]
  TOTAL SECTION B: 80

SECTION C
QUESTION 4
Regulation of body temperature during the race

• The body temperature increases ✓
• because of the increased cellular respiration ✓
• The hypothalamus ✓ is stimulated and sends impulses to the blood vessels in the skin causing them to dilate ✓/vasodilation takes place
• More blood flows through the surface of the skin ✓
• More heat is lost through the skin ✓/radiation
• More blood is sent to the sweat glands ✓
•  More sweat is produced ✓/the sweat glands become more active/more sweat is released
• Evaporation of sweat cools the body ✓/more heat to be lost

Regulation of water balance during the race

• Because of sweating the blood has less water than normal ✓
• The hypothalamus is stimulated ✓
• and sends impulses to the pituitary gland to secrete more ADH ✓
• ADH travels in the blood to the kidneys ✓
• ADH increases the permeability of the collecting ducts ✓/ the distal convoluted tubules
• More water is reabsorbed and passed to the surrounding blood vessels ✓
• The water level in the blood returns to normal ✓ (Any 12) (12)

Pupillary reflex mechanism

• In bright light ✓
• the circular muscles ✓
• of the iris ✓
• contract ✓
• and the radial muscles relax ✓
• the pupil constricts ✓
• allowing less light to enter the eye ✓ (Any 5) (5)

ASSESSING THE PRESENTATION OF THE ESSAY

Content: (17)
Synthesis: (3)

TOTAL SECTION C: 20
GRAND TOTAL: 150