Gr 12-Life Sciences-Facilitator's Guide

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LIFE SCIENCES FACILITATOR’S GUIDE

Grade 12

A member of the FUTURELEARN group

Life Sciences Facilitator’s guide

1812-E-LIS-FG01

Í2,È-E-LIS-FG017Î

Grade 12

CAPS aligned

ANSWER GUIDE

AUTHORS Jen Grogan Ruth Suter

LIFE SCIENCES GRADE 12 NCAPS ANSWER GUIDE

ALL RIGHTS RESERVED ŠCOPYRIGHT BY THE AUTHOR The whole or any part of this publication may not be reproduced or transmitted in any form or by any means without permission in writing from the publisher. This includes electronic or mechanical, including photocopying, recording, or any information storage and retrieval system.

Every effort has been made to obtain copyright of all printed aspects of this publication.

However, if material requiring copyright has unwittingly been used, the copyrighter is requested to bring the matter to the attention of the publisher so that the due acknowledgement can be made by the author.

Life Sciences Answer Guide Grade 12 NCAPS ISBN-13:

978-18692-1-882-9

Product Code:

LFS 73

Authors:

Jen Grogan Ruth Suter

First Edition:

August 2015 (Revisions based on Examination Guidelines - Grade 12, from 2014)

Second Edition:

May 2016 (Minor revisions, includes addendum)

PUBLISHERS ALLCOPY PUBLISHERS P.O. Box 963 Sanlamhof, 7532

Tel: (021) 945 4111, Fax: (021) 945 4118 Email: info@allcopypublishers.co.za Website: www.allcopypublishers.co.za

i

LIFE SCIENCES ANSWER GUIDE GRADE 12 NCAPS CONTENTS

Page no.

1.1

DNA: Code of life

20

1.2

Meiosis

22

1.3

Genetics and Inheritance

25

2.1

Diversity of vertebrate reproductive strategies

32

2.2

Human reproduction

33

2.3.1 Human nervous system

36

2.3.2 Receptors

40

2.4

Human endocrine system

45

2.5

Human homeostasis

48

2.6

Plant responses to environment

50

3

Human impact on environment

52

4.1

Evolution

61

4.2

Evolution of humans

66

4.3

Hominin fossil sites

71

4.4

Alternatives to evolution

75

ii

To the educator The emphasis of the Mind Action Series Life Science 12 Textbook is to present the work simply in a clearly laid out format.

There are many learning activities of different types to help the learner understand the work and to consolidate what has been taught.

Each learner will develop his/her own way of creating learning diagrams, mind maps, flow charts etc and it is very important that the you encourage them to do these activities. Some of these involve assessment by peers which allows learners to learn from each other and reflect on their own performance.

The Educator’s Guide and Answers The Educator’s Guide and Answers is an invaluable supplement to the textbook in that it will assist you, the educator, to effectively complete all the requirements of the new curriculum as put forward in the Curriculum and Assessment Policy Statement (CAPS).

You will find the following useful features in this guide: A. Organisation of the life science curriculum p2 B. The specific aims of Life Sciences

p3

C. What the learners will need

p3

D. Work schedule

p4

Term 4

Grade 11

p 4

Term 1

Grade 12

p 6

Term 2

Grade 12

p 9

Term 3

Grade 12

p 12

E. Short introduction to each strand and module p 14 Strand 1

p 14

2.5 Homeostasis

1.1 DNA; the code of life

p 15

2.6 Response by plants to environment p 17

1.2 Meiosis

p 15

Strand 3

p 18

1.3 Genetics and inheritance

p 15

Environmental Studies

p 18

Strand 2

p16

Strand 4

p 18

2.1 Vertebrate reproductive strategies

p 16

4.1 Evolution by natural selection

p 18

2.2 Human reproduction

p 17

4.2 Evolution of humankind

p 18

2.3 Human responses to the environment p 17

4.3 Hominin fossil sites

p 19

2.4 Endocrine system

p 17

4.4 Alternatives to evolution

p 19

F. Answers

p 20

1.1 DNA: code of life

p 20

2.5 Homeostasis in humans

p 48

1.2 Meiosis

p 22

2.6 Plant responses to environment

p 50

1.3 Genetics & Inheritance

p 25

3

p 52

2.1 Vertebrate reproductive strategies

p 32

4.1 Evolution

p 61

2.2 Human reproduction

p 33

4.2 Evolution of humankind

p 66

2.3 Human responses to environment

p 36

4.3 Fossil sites in Africa

p 71

2.4 Human endocrine system

p 45

4.4 Alternatives to evolution

p 75

1

Human impact on environment

p 17

G. Assessment plan 

How are learners assessed?

p 77



What are the assessment requirements?

p 79



Mark distribution information

p 80

A. Organization of the Life Science curriculum Four Knowledge Strands are used to organize the Life Sciences content framework. These knowledge strands are developed progressively over the three years of the FET. They are: 1.

2.

3.

4.

Life at the Molecular, Cellular and Tissue Level Life Processes in Plants and Animals Environmental Studies Diversity, Change and Continuity

The knowledge strands and the topics within each knowledge strand cannot be studied separately and in isolation. It is important that learners understand that topics are related and that biological systems do not function independently or in isolation. The educators in all the three grades should be aware of this continuity.

Knowledge

Life at molecular,

Life processes in

Environmental

Diversity, change &

strands

cellular & tissue level

plants & animals

studies

continuity

 Chemistry of life –

 Support and

 Biosphere to

 Biodiversity and

Inorganic and organic compounds

Grade 10

 Cell – unit of life  Cell division – mitosis  Plant tissues

transport systems in

ecosystems

classification  History of life and

plants  Support systems in

Earth

animals  Transport systems in mammals (human)

 Animal tissues  Energy

 Population ecology

transformations to

Grade 11

 Human impact on

 Biodiversity – classification of

support life:

environment: current

micro-organisms

Photosynthesis

crises Information for

 Biodiversity – plants

 Animal nutrition

this is in this

 Reproduction –

 Energy

educator’s guide

plants  Biodiversity –

transformations: Respiration

animals

 Gas exchange  Excretion  DNA – code of life  RNA and protein synthesis

Grade 12

 Meiosis

 Reproductive

 Human impact on

 Darwinism and

strategies in

environment: current

Natural Selection

vertebrates

crises To be done in

 Human Evolution

 Human reproduction  Nervous system  Senses  Endocrine system  Homeostasis

2

Grade 11

B. What are the specific aims of Life Sciences?

1. The first aim is that learners should: 

understand what they are being taught



understand certain scientific terms and ideas



learn what they have been taught; not off by heart, but through a number of exercises such as drawing mind maps, diagrams, making tables etc, as well as by testing their knowledge and understanding as they go along.

These are all provided for in this text book.

2. The second aim is that learners: 

should develop the curiosity to want to know how and why certain changes happen.



have practical experience in investigating and discovering answers to these questions.

They must have this practical experience for both assessment and examination purposes.

The textbook explains what skills are required for an investigation or an experiment and also gives alternative suggestions regarding equipment, so that if you do not have the resources, it is possible to use everyday articles, which are easily available.

In these practical investigations the learners have an opportunity: 

to apply the knowledge they have gained



to develop skills, particularly those of:  observing  recording  interpreting data.

3. The third aim is that learners should: 

be able to understand the role and application of Life Sciences in everyday life



appreciate the importance of indigenous knowledge in this respect.



know a certain amount of the history of science.

C. What will the learners need?

They will need:  a file 

foolscap paper



plastic sleeves (optional)

The files are very important as they will ensure that the learner’s work is kept intact, which will include:  answers to all the informal tests (Learning activities) 

learning diagrams/flow charts/mind maps



extra notes, graphs, etc from in class.

3

D. Work schedule The work schedule provides:  an outline as to what topics should be covered during each week of all four terms; the order of which is the same as the prescribed order from the DOE.  page numbers of the various topics to help complete the syllabus in the prescribed time.  SBA = School Based Assessment

Grade 11 NB This work should be done in the final term in Grade 11.

Term 4 Week

Module

Content

Investigation/Practical

Assessment Informal/formal Informal – Learning activities in text book

Formal – see below Can be used for SBA

1

3

Human impact on the environment (217 – 264)

LA 1, p 218

LA 2 , p 219

Carbon footprint

The effects of

A. Atmosphere & climate change,

LA 3 , p 221

p 217

Greenhouse effect

deforestation LA 4, p 222

1.

CO2 emissions, p 217

Pie graph to show

2.

Carbon footprint, p 218

greenhouse gases

3.

Deforestation, p 219

4.

Greenhouse effect/global warming, p 220

5.

Methane emissions, p 221

6.

Ozone depletion, p 222

LA 5, p 223 Ozone depletion

LA 6, p 224 Short questions

2

3

B. Water availability, p 225

LA 1, p 227

LA 2, p 229

1.

Construction of dams, p 226

Draw a map of a local

Essay on scarcity of

2.

Destruction of wetlands, p 226

wetland. List fauna and

water in South Africa

3.

Poor farming practices, p 227

flora,

4.

Droughts & floods, p 227

5.

Exotic plantations/depletion of water table, p 228

3

3

6.

Boreholes/ effects on aquifers, p 228

7.

Wastage of water, p 229

8.

Cost of water, p 229

C. Water quality, p 230

LA 4, p 232

LA 3, p 230

1. How using water affects its quality, p 230

Flow chart to illustrate

Water consumption

2. Effect of mining on water quality, p 232

eutrophication

3. Thermal pollution, p 233

LA 5, p 235 Factors affecting water

4. Water purification/recycling, p 234

quality

5. Alien plants, eg Eichornia, p 235

LA 6, p 236 Short questions

4

4

3

D. Food security, p 237

LA 1, p 239

Factors affecting food security, p 238

Poor farming practices

1.

Human population growth, p 238

2.

Droughts and floods, p 238

3.

Poor farming practices, p 238

4.

Alien plants and reduction of

LA 2, p 241 Loss of wild varieties

agricultural land, p 239

5

3

5.

Loss of wild varieties, p 240

6.

Genetically engineered foods, p 241

LA 3, p 242

LA 4, p 242

7.

Wastage, p 242

Class debate on

Short questions

genetically engineered foods

6

3

E. Loss of biodiversity, p 243

LA 1, p 245

LA 2, p 246

1.

Habitat destruction, p 244

Habitat destruction

Rhino poaching

2.

Poaching , p 245

3.

Alien plant invasion, p 248

4.

Indigenous knowledge systems, p 250

5.

Sustainable use of environment -

LA 3, p 249 Control of alien invasives

Devil’s claw, rooibos, fynbos, African

LA 4, p 252

Potato, Hoodia , p 250

Test on indigenous knowledge and medicinal plants

LA 5, p 253 Rooibos

LA 6, p 254 Fynbos

LA 7, p 255 Short questions

7

3

F. Solid waste disposal, p 257

LA 1, p 259

LA 4, p 261

1.

Managing dumpsites for rehabilitation,

Visit a landfill site or

Recycling - methane

p 257

refuse dump

from dumpsites

LA 2, p 259

LA 5, p 263

Rehabilitation of

Disposal of nuclear

dumpsites

waste

LA 3, p 260

LA 6, p 263

Solid waste analysis

Human influence on

2.

Need for recycling, p 260

3.

Methane from dumpsites for domestic use, p 261

4.

Disposal of nuclear waste, p 262

environment. A written report on subject chosen

LA 7, p 264 Short questions

5

DBE Examination guidelines to be used with following schedule Grade 12 Term 1 Week

Module

Content

Investigation/Practical

Assessment Informal/formal Informal – Learning activities in text book Formal – see below Can be used for SBA

1

1.1

Deoxyribonucleic acid (DNA)

LA 3, p 5

LA 1, p 2

(1 – 18)

Extraction of DNA molecules from onion skins

DNA; its discovery and location

Location in cell, p 1

LA 2, p 4

Discovery of DNA – Watson, Crick, Franklin and Wilkens, p 2

Structure and importance of DNA

Structure of DNA, p 3 Role of DNA: genes & non-coding DNA, p 4

1.1

Replication p 7-8

LA 4, p 8

Ribonucleic acid

Replication

Structure of RNA, p 11

LA 5, p 10

Protein synthesis, p 12

DNA profiling & forensics

A. Process in nucleus

LA 6, p 12

B. Process at ribosomes, p 13

Differences between DNA & RNA LA 7, p 13 Protein synthesis LA 8, p 14

Genetic code, p 15

2

General questions LA 9, p 16

1.2

Short questions

Meiosis (19 – 34)

LA,1, p 19

Background information, p 17

Chromosomes

Meiosis 1, p 20 Meiosis 2, p 21

LA 3, p 22

LA,2, p 21

Purposes of reduction division, p 25

Meiosis

Importance of meiosis, p 25

LA 5, p 24

Meiosis 2 – a copying division

Identifying micrographs

LA 4, p 23 Meiosis and crossing over LA 6, p 25 Cell divisions & chromosome numbers

3

Genetic variation, p 26

LA 7, p 28

LA 8, p 28

Consequences of abnormal meiosis, p 26

Class debate on abortion

Chromosome mutations

Similarities and differences between Mitosis and Meiosis, p 30

LA 9, p 31 Diagrams to illustrate differences between

6

meiosis and mitosis LA 10, p 32 Short questions

3

2.1

Vertebrate reproductive strategies (73 – 82)

LA 1, p 74 Internal vs external fertilisation

External or internal fertilisation, p 73

LA 2, p 75 Ovipary

Ovipary, ovovivipary, vivipary, p 74 Amniotic egg, p 76

LA 3, p 78 Precocial and altricial

Precocial & altricial development, p 76 Parental care, p 78

LA 4, p 80 Reproductive strategies LA 5, p 82 Short questions

4

2.2

Human reproduction (83 – 115) Structure male and female reproductive systems (link to grade 7 and 9), p 83 -88 1. Puberty, p 89

Identify tissues and different structures of ovary, testis and penis using prepared slides or micrographs from the internet and/or textbook LA 2, p 85 Male reproductive organs

LA 1, p 84 Testis structure LA 3, p 87 Fallopian tubes LA 4, p 88 Structure and functioning of the female reproductive system LA 5, p 90 Physical changes during puberty

5

2.2

2. Gametogenesis: relate briefly to meiosis (no individual names of stages), p 90 3. Menstrual cycle; emphasis on hormonal control, p 94 4. Fertilisation and development of zygote to blastocyst, p 99

LA 11, p 100 Blastocyst formation

LA 6, p 91 Summary of spermatogenesis LA 7, p 92 Spermatogenesis LA 8, p 95 Ovary structure, Gametogenesis and Differences between gametes LA 9, p 97 The menstrual cycle LA 10, p 100 Fertilisation LA 12, p 101 Embryonic development and implantation

7

6

2.2

5. Gestation; brief mention, p 99 6. Implantation and development; role of placenta, p 100

LA 13, p 103 Development during foetal stage

LA 14, p 106 Placenta functions

Observe stages of pregnancy, p 107

LA 15, p 106 Functions of amniotic fluid

LA 16, p 107 Gestation

LA 17, p 110 Stages of childbirth

It is strongly advised that the learners watch National Geographic’s DVD, In the Womb. With the latest technology one is able to see in amazing detail the foetus as it develops.

LA 19, p 113 Short questions

There are many DVD’s of development of embryo and birth process, these should be used.

Observe contraceptive devices, p 110 LA 18, p 112 Contraception

7

1.3

Genetics & inheritance (35 – 72)

Solving genetic problems:

Mendel; ‘the father of genetics’ p 35

LA 2, p 40 Complete dominance

Concepts of inheritance, 35 - 43 

Genes/alleles, p 35 – 37



Dominant and recessive, p 37



Phenotypes and genotypes, p 37



Homozygous and heterozygous, p 37

LA 3, p 41 Test crosses

Monohybrid crosses/Types of dominance, p 40 - 45

8

1.3



Genetic diagrams, p 40



Complete dominance, p 40



Test crosses, p 41



Incomplete dominance, p 42



Co-dominance, p 42

LA 6, p 43 Monohybrid crosses

LA 7, p 44 Inheritance of sex

Blood grouping, p 45 - 46 Mutations, p 46 – 51 Harmful, harmless & useful mutations, p 47 - 48

Genetic disorders, 48 - 52 

Albinism, p 50



Cystic fibrosis, p 51

LA 4, p 42 Incomplete dominance LA 5, p 42 Co-dominance/blood groups

Sex determination, p 43 – 45



LA 1, p 38 Genetic terms

LA 8, p 46 Blood grouping LA 9, p 49 Haemophilia LA 10, p 50 Red-green colour blindness

Sex inheritance p 48 - 50 Chromosome aberrations, p 48

8

LA 11, p 51 Mutations, albinism, cystic fibrosis

Sex-linked characteristics, p 48 Sex-linked diseases, 48 - 50 1.

Haemophilia, 48 - 49

2.

Colour blindness, p 49 - 50

Term 2 Week

Module

Content

Investigation/Practical

Assessment Informal/formal

1

1.3

Genetic lineages, p 52 – 53 Genetic testing and counselling, p 52

LA 12, p 52 Family trees

Genetic engineering, p 53 – 65 1.

Stem cell research, p 53 - 54

2.

Genetic modification, p 55 - 59

3.

Cloning, p 59 – 61

LA 14, p 57 Recombinant DNA technology LA 17, p 61 Class discussion on controversial topics

Paternity testing, p 62 - 65

LA 18, p 62 Class debate on the hazards of genetic engineering LA 20, p 63 Paternity testing

2

3

1.3

2.3.1

Genetic links, p 64 - 65 Dihybrid crosses, p65 - 67

Human responses to the environment (117 – 178) Human nervous system A. Central nervous system

Cerebrum, p 120 Cerebellum, p 121 Medulla oblongata, p 122 2. Spinal cord, p 124 B. Peripheral nervous system, 126 1. Somatic nervous system, p 126 2. Autonomic nervous system, p 127 Nerves, p 130

2.3.1

Nervous tissue, p 131 – 138 Neurons, p 131

Reaction time, p 136 Synapses, p 137 Disorders of nervous system, p 138

9

LA 16, p 61 Cloning LA 19, p 62 Essay on genetic engineering LA 21, p 65

Dihybrid crosses

Genetic links/mDNA

LA 23, p 67 Black rhino case study

LA 24, p 68 Short questions

LA 3, p 121 Learning diagram functions of the cerebellum

LA 1, p 117 Co-ordination

LA 5, p 122 Practical investigation to identify parts of a sheep’s brain LA 7, p 125 Learning diagram – functions of the spinal cord

LA 8, p 125 Practical investigation to show structure of spinal cord

Reflex arc, p 134

LA 15, p 59 Genetically modified organisms

LA 22, p 66

LA 4, p 122 Learning diagram -functions of the medulla

1. Brain, p 119 – 123

4

LA 13, p 54 Stem cells

LA 13, p 136 Investigating reaction times

LA 2, p 120 Functions of cerebrum LA 6, p 123 General questions brain LA 9, p 126 General questions on nervous system LA 10, p 130 Autonomic nervous system LA 11, p 133 Neurons LA 12, p 135 Reflex arc and actions LA 14, p 138 Synapses

Injuries, p 140

Effects of drugs on CNS, p 142

LA 17, p 146 Effects of drugs

LA 15, p 139 Disorders of N/S LA 16, p 141 Injuries to N/S LA 18, p 147 Short questions

5

2.3.2

Receptors – detection of stimuli, 151 Human Eye, p 152 – 166 Structure and functioning,152 Binocular vision, p 160 Accommodation, p 160

LA 20, p 157 Dissection of a sheep’s eye

LA 19, p 156 Pupillary mechanism

LA 21, p 158 Functions of parts of the eye

LA 23, p 160 Functioning of the eye

LA 22, p 159 Photoreceptors

Visual defects, p 162

LA 24, p 161 Design a diagram to illustrate viewing distant objects

LA 25, p 161 Accommodation LA 26, p 163 Visual defects 1

LA 27, p 165 Visual defects 2

2.3.2

Human ear, 167 - 173 Structure & functioning; hearing & balance Hearing defects, p174

LA 28, p 168 Structure & functions of the middle ear LA 29, p 170 Cochlear LA 30, p 171 Vestibular apparatus LA 31, p 172 Hearing and balance LA 32, p 175 Hearing defects LA 33, p 176 Short questions

6

2.4

Human endocrine system (179 – 195) Position of glands, hormone secreted, role of hormones of the following: 1.

Hypothalamus: ADH, p 179

2.

Pituitary gland: TSH, FSH, LH, prolactin, growth hormone (link to reproduction), p 179

3.

Thyroid gland: thyroxin, p 181

4.

Pancreas: insulin, glucagon; diabetes, p 183

LA 1, p 181 Hypothalamus and pituitary hormones LA 2, p 182 Thyroid gland and its functioning LA 3, p 185 Homeostatic control of glucose LA 4, p 188 Diabetes

10

5.

Adrenal glands: aldosterone, adrenalin, p 188

6.

Gonads: oestrogen, progesterone and testosterone (link to reproduction), p 191

LA 7, p 191 Hormones of the reproductive system

 TSH, p 182

LA 9, p 193 Short questions

 Insulin and glucagon p 186 and 184

2.5

LA 6, p 191 Oestrogen functions LA 8, p 192 General endocrine questions

Examples of negative feedback mechanisms:

7

LA 5, p 189 Adrenalin

Homeostasis (197 – 206)

LA 1, p 198 Homeostatic control of carbon dioxide

Negative feedback:  Glucose – see above

LA 2, p 199 Homeostatic control of water by ADH

 Carbon dioxide, p 197  Water and salts, p 198 Thermoregulation:

LA 3, p 199 Homeostatic control of salts

Adaptations of human skin, p 201 Vasoconstriction, Vasodilatation, Sweating, p 202

LA 4, p 200 Heat loss and heat gain LA 5, p 203 Thermoregulation in humans LA 6, p 204 Class discussion LA 7, p 205 Short questions

8

2.6

Plant responses to environment (207 – 216)

LA 3, p 210 Geotropism investigation

LA 1, p 208 Auxins

Plant hormones: general functions,

LA 4, p 211 Geotropism investigation

LA 2, p 209 Phototropism

1. Auxins, p207

LA 5, p 213 Functions of gibberellins and abscisic acid

Tropisms and auxins, p 208 Phototropism, p 208 Geotropisms, p 208 2. Gibberellins, p 212

LA 6, p 215 Plant defences

3. Abscisic acid, p 212 Plant defence mechanisms p 213

LA 7, p 215 Short questions

 Chemical, p 213  Physical, p 214

11