GRADE 12 LIFE SCIENCES P1 NOVEMBER 2017 EXAMINATION NOTES

GRADE 12 LIFE SCIENCES P1 NOVEMBER 2017 EXAMINATION NOTES

EXAM FORMAT

  • Total Marks: 150

  • Duration: 2½ hours

  • Page Count: 15

INSTRUCTIONS AND INFORMATION

  1. Answer ALL questions.

  2. Write ALL answers in the ANSWER BOOK.

  3. Start answers on a NEW page for each question.

  4. Number answers according to the question paper's numbering system.

  5. Follow the presentation instructions for each question carefully.

  6. Draw diagrams in pencil and label them in blue or black ink.

  7. Diagrams are not necessarily to scale.

  8. Do NOT use graph paper.

  9. Use a non-programmable calculator, protractor, and compass as necessary.

  10. Write neatly and legibly.

SECTION A

QUESTION 1: MULTIPLE CHOICE
1.1 Select the correct answer (A to D) for each question:

1.1.1 Function of the Brain - Higher Thought Processes

  • Options:
    A. cerebellum
    B. medulla oblongata
    C. hypothalamus
    D. cerebrum
    1.1.2 Central Nervous System Composition

  • Options:
    A. cranial and spinal nerves
    B. brain and spinal cord
    C. sympathetic and parasympathetic nerves
    D. autonomic and peripheral nervous systems
    1.1.3 Dark-Coloured Eye Layer Rich in Blood Vessels

  • Options:
    A. Conjunctiva
    B. Sclera
    C. Cornea
    D. Choroid
    1.1.4 Eye Structure Containing Photoreceptors

  • Options:
    A. Retina
    B. Iris
    C. Sclera
    D. Vitreous humour
    1.1.5 Light Refraction in the Eye

  • Options:
    A. Pupil and iris
    B. Blind spot and yellow spot
    C. Cornea and lens
    D. Sclera and suspensory ligaments
    1.1.6 Focusing on Distant Object from Close Reading

  • Options:
    A. Radial muscles of the iris contract
    B. Pupil becomes dilated
    C. Ciliary muscles relax
    D. Lens becomes more convex
    1.1.7 Pathway of a Reflex Arc

  • Options:
    A. Muscle → Spinal cord → Brain
    B. Effectors → Spinal cord → Receptor
    C. Receptor → Spinal cord → Brain
    D. Receptor → Spinal cord → Muscle
    1.1.8 Reason for Limited Time in Steam Room

  • Options:
    A. Increased sweating will cause overcooling
    B. Sweat will not evaporate causing overheating
    C. Vasoconstriction will lower sweat production
    D. Heat receptors in the skin will be damaged
    1.1.9 Effect of Hypothalamus Tumour on Diabetes Insipidus

  • Options:
    A. Increased secretion of TSH
    B. Decreased secretion of ADH
    C. Increased reabsorption of water in the kidneys
    D. Increased permeability of collecting ducts to water
    1.1.10 Content of Contraceptive Pills

  • Options:
    A. high levels of FSH and progesterone
    B. high levels of LH and oestrogen
    C. high levels of only FSH
    D. high levels of only progesterone

QUESTION 1.2: BIOLOGICAL TERMS

  • Provide the correct biological term for each description: 1.2.1 Fertilisation

    • Definition: A type of fertilisation in which the nucleus of a sperm fuses with the nucleus of an ovum outside the body of the female.
      1.2.2 Chromatid Overlap

    • Definition: The point where two chromatids overlap during prophase I.
      1.2.3 Hormone Regulation

    • Definition: A hormone which regulates the salt balance in the human body.
      1.2.4 Homeostasis

    • Definition: The maintenance of a constant internal environment in the human body within certain limits.
      1.2.5 Egg Type

    • Definition: A type of egg where the embryo develops inside a fluid-filled sac which is surrounded by a shell.
      1.2.6 Hormone Development

    • Definition: A hormone that stimulates the development of the corpus luteum.
      1.2.7 Eye Disorder

    • Definition: A disorder of the eye caused by the curvature of the lens or cornea being uneven, resulting in distorted images.
      1.2.8 Structure for Brain Communication

    • Definition: The structure that connects the left and right hemispheres of the brain, allowing communication between them.
      1.2.9 Nerve Function

    • Definition: The nerve that carries impulses from the retina to the brain.
      1.2.10 Protective Membranes

    • Definition: Collective name for the membranes that protect the brain and spinal cord.

QUESTION 1.3: COLUMN INFERENCE

  • Indicate applicability for descriptions: 1.3.1 Greenhouse Gas Reduction

    • A only (Landfill sites)

    • B only (Deforestation)

1.3.2 Bird Reproductive Strategy

  • A only (Precocial)

  • B only (Altricial)

1.3.3 Vertebrate Reproduction

  • A only (Vivipary)

  • B only (Ovovivipary)

QUESTION 1.4: NERON STRUCTURE

1.4.1 Identify Neuron Type

  • Type of neuron: [Answer Required]
    1.4.2 Identify Neuron Parts

  • a) [Label B]

  • b) [Label F]

  • c) [Label A]

1.4.3 Functions of Neuron Parts

  • a) [Part Transmitting Impulses Away from Cell Body]

  • b) [Part Insulating and Speeding Up Transmission]

1.4.4 Degradation Condition

  • Condition caused by degradation of part D: [Answer Required]

QUESTION 1.5: HORMONES AND GLUCOSE REGULATION

1.5.1 Identify Organ and Hormones

  • Organ 1: [Answer Required]

  • Hormone 2: [Answer Required]

  • Hormone 3: [Answer Required]

1.5.2 Disorder

  • Disorder caused when organ 1 fails to release sufficient amounts of hormone 2: [Answer Required]

1.5.3 Controlling Glucose Levels

  • Mechanism controlling levels of glucose in the body: [Answer Required]

TOTAL SECTION A: 50

SECTION B

QUESTION 2: WATER RESOURCES
2.1 DAM WATER LEVELS

  • Graph Analysis of Percentage Water in Dams,

  • Key Questions:

    1. Identify province with most water in February 2017.

    2. Identify province with greatest water decrease from 2016 - February 2017.

    3. Calculate percentage increase in North West's water (33.4%) from 2016 to February 2017.

    4. Name TWO provinces with the lowest dam water in February 2017.

    5. Suggest TWO strategies to reduce water shortages (beyond restrictions).

    6. Explain TWO negative environmental impacts of building dams.

QUESTION 2.2 FOOD SECURITY
ARMY WORM INVASION

2.2.1 Definition of Food Security

  • Definition: [Provide Detailed Definition]
    2.2.2 Alien Species Reference

  • Phrase implying army worm as alien: [Quote Required]
    2.2.3 Army Worm Introduction to Africa

  • Two methods by which army worm may have been introduced: 1. [Method One]

  • [Method Two]
    2.2.4 Control Method Identification

  • Type of control used: [Identify Control Type]
    2.2.5 Economic Impact Explanation

  • One negative influence of army worm on economy: [Impact Required]

QUESTION 2.3 MEIOSIS
MEIOSIS PHASE DIAGRAM

2.3.1 Identify Phase in Diagram

  • Answer: [Meiosis Phase Label]
    2.3.2 Visible Reasons

  • Reason 1: [Visible Characteristic]

  • Reason 2: [Visible Characteristic]
    2.3.3 Chromosomes Count

  • a) Number in each cell: [Answer Required]

  • b) Was present in original cell: [Answer Required]
    2.3.4 Processes Leading to Different Cells

  • Process 1: [Name Required]

  • Process 2: [Name Required]

  • Significance: [Explain Significance]

QUESTION 2.4 FETAL DEVELOPMENT

2.4.1 Identify Parts of Fetus

  • a) A: [Identification Required]

  • b) C: [Identification Required]
    2.4.2 Fluid Functions

  • Functions of fluid in part B: 1. [Function One]

  • 2: [Function Two]
    2.4.3 System Post-Birth

  • System taking over function of part D post-birth: [Name Required]
    2.4.4 Negative Impact of Reduced Part D

  • Explanation: [Negative Impact Required]

TOTAL SECTION B: 80

SECTION C

QUESTION 4: SPERM PRODUCTION AND FERTILIZATION

  • Describe processes in sperm production, transportation, and fertilization.

  • Explain THREE structural adaptations of sperm for fertilization.