SSIP – January 2020 SUBJECT: LIFE SCIENCES Participant's Guide

SSIP – January 2020 SUBJECT: LIFE SCIENCES Participant’s Guide

This work is protected by the Copyright Act 98 of 1978. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without permission in writing from Matthew Goniwe School of Leadership and Governance.

Whilst every effort has been made to ensure that the information published in this work is accurate, Matthew Goniwe School of Leadership and Governance takes no responsibility for any loss or damage suffered by any person as a result of the reliance upon the information contained therein.

Table of contents

Page

A Foreword 4

B Purpose 4

C Overall SSIP purpose/goals 4

D Programme outcomes 4

E Learning assumed to be in place 4

F Target audience 5

G Notional hours 5

H Course design and assessment strategy 5

Annual teaching plan (ATP) 8

Cognitive demand levels in Life Sciences 10

Course timetable 12

Module 1: DNA and Protein synthesis 16

Module 2: Meiosis 40

Module 3: Reproductive strategies in Vertebrates 61

Module 4: Reproduction in humans 76

A. FOREWORD This Just in Time teacher training workshop is organized at the start of term 1. All topics to be covered in term 1 by the gr.12 teacher will be mediated to enable teachers to unlock the content for the learners. The dates for the workshops were announced in 2019 at a joint meeting with Matthew Goniwe School of Leadership and Governance (MGSLG) and Teacher Development (TD). The topics chosen for emphasis for the workshop were implicated in the diagnostic reports on the NSC 2019 November examinations as well as the analytical report compiled by the province, as problematic topics. Teachers have also expressed the need for content and pedagogical training in these topics.

Therefore, not only content, but also hands-on activities on how to teach DNA, RNA and protein synthesis; Meiosis, Reproduction in Vertebrates and Human reproduction will be part of the workshop content. The formal SBA task to be done in term 1 will also be performed to ensure common understanding. Typical exam questions on these topics will also be unpacked. ICT integration will be demonstrated by the facilitators.

B. PURPOSE Training Course Goals: Professional development for teachers from schools at risk to improve the quality of teaching and learning in the targeted schools.

C. OVERALL SSIP AIMS/GOALS The SSIP programme aims at professional development for Grade 10-12 teachers in the application of effective teaching and reflective practice to improve learner performance on the identified Grade 12 examinable topics. The overall goal for SSIP is to provide teachers with professional expertise, tools and skills to spot student learning difficulties and decide on the course of action.

SSIP came about as a result of the diagnostic needs that are identified through the end of the year NSC examination student learning data. In response to this, design and development of teaching resources will lead to the training of teachers on learners’ needs identified.

The four interconnected outcomes that drive the professional development activities for SSIP are:

1. Enhancing Teachers’ knowledge: deep understanding of subject matter knowledge and student’s ideas on the content. 2. Enhancing quality teaching and assessment for learning: effective instructional approaches that teachers may use to ensure improved understanding by most learners. 3. Developing ICT integration skills: Use of ICT to improve teaching and learning. 4. Building professional learning communities: allow teachers to start collaborating and form professional networks in non-formal settings in the context of their schools.

PROGRAMME OUTCOMES

Professional development to improve learner outcomes in the identified term 1 Life Sciences topics.

E. LEARNING ASSUMED TO BE IN PLACE

Teachers who are qualified to teach Life Sciences in grade 10 – 12 (FET Phase)

F. TARGET AUDIENCE

Grade 12 teachers who have obtained below 70% in the 2019 NSC results and grade 12 novice teachers.

G. NOTIONAL HOURS

The time required to successful completion has been allocated as follows: Contact face to face session 16 hours

Pre Test ½ hour

Day 2 : Content Practice and Demonstration 9¼ hours

Day 3: Content Practice and Demonstration 5½ hours

Post Test ½ hour

H. COURSE DESIGN AND ASSESSMENT STRATEGY

The course will focus on content, teaching and learning approaches and assessment and it will use both pre-pot tests and activities to monitor participants’ progress and understanding of the term 1 topics for Life Sciences

COURSE OUTLINE/ MAP

MODULE 1: DNA and PROTEIN SYNTHESIS MODULE 2: MEIOSIS

Objectives/Outcomes Objectives/Outcomes

When you complete this module, you will be When you complete this module, you will be able to: able to:

• Teach the terminology associated with DNA • Teach the terms associated with meiosis and protein synthesis. • Indicate where meiosis take place in animals • Create a crossword puzzle on line and plants • Describe the structure of DNA and RNA • Discuss and interpret the process of meiosis structures • Explain the process of non-disjunction and • Perform a DNA extraction interpret it from karyographs and other • Differentiate between DNA and RNA diagrams • Describe DNA replication • Explain Down syndrome • Differentiate between translation and transcription and explain the two processes. • Discuss DNA profiling and its applications • Administer the Grade 12 Term 1 SBA task

MODULE 3: REPRODUCTIVE STRATEGIES IN MODULE 4: REPRODUCTION IN HUMANS VERTEBRATES

Objectives/outcomes Objectives/outcomes

When you complete this module, you will be When you complete this module, you will be able to: able to:

• Teach the terminology associated with • Teach the terminology associated with reproductive strategies in vertebrates human reproduction • Apply knowledge of the concepts to case • Classify questions on the different levels of studies. Bloom’s taxonomy. • Answer questions on human reproduction.

ICONS USED IN THIS MODULE

1. Discussion

2. Group Activity

3. Individual Activity

4. Study/Teaching Tips

5. Notes

6. Ice Breaker

WEEK 1 WEEK 2 WEEK 3 WEEK 4 WEEK 5 WEEK 6 WEEK 7 WEEK 8 WEEK 9 WEEK 10 WEEK 11 15 – 17 Jan 20 – 24 Jan 27/01 –31/01 03/02– 7/02 10 – 14 Feb 17 – 21 Feb 24/02 - 28/02 02/03 – 06/03 9 – 13 Mar 16 – 20 Mar 31/03 – 03/04 DNA, RNA and meiosis Reproduction Genetics • Revision of the • DNA RNA • Mitosis • Meiosis I • Reproductio • Gametogenesis • Fertilisation • Genetics • Sex determination • Dihybrid structure of the • Transcription (Revision) • Meiosis II n in • Structure of an • Implantation • Monohybrid • Sex-linked Inheritance crosses cell • Translation • Chromoso • Non- Vertebrates ovum and sperm • Gestation crosses • Blood groups • Genetic mes disjunction • Structure • Menstrual Cycle pedigree and function • Ovarian cycle of the ♀ and • Uterine cycle SBA Practical ♂reproductiv Test term 1 task 1 e systems (40%) (4%) (8%) (12%) (20%) (24%) (28%) (32%) (36%) (44%) (16%) WEEK 12 WEEK 13 WEEK 14 WEEK 15 WEEK 16 WEEK 17 WEEK 18 WEEK 19 WEEK 20 WEEK 21 WEEK 22 6 - 9 Apr 14 – 17 Apr 20 - 24 Apr 28 – 30 Apr 4 - 8 May 11 - 15 May 18 May – 12 June 7 – 10 Jul Genetics Human nervous system • Mutations • Human nervous • Reflex arch • The eye • The ear • Human • Homeostasis • Genetic system • Disorders of CNS • Accomm • Balance endocrine In Humans Engineering odation system Midyear examination • Paternity • Pupillary • Negative testing mechanis feedback • Genetic Links m mechanism

Assignment Test term 2 SBA Practical task 2 (56%) (60%) (64%) (68%) (72%) (48%) (52%) WEEK 23 WEEK WEEK 24 WEEK 25 WEEK 26 WEEK 27 WEEK 28 WEEK 29 WEEK 31 WEEK 32 WEEK 33 30 13 – 17 Jul 20 – 24 Jul 27/07– 31/07 3 - 7 Aug 11 – 14 Aug 17– 21 Aug 24 – 28 Aug 31/8 – 4/9 7 – 11 Sep 14 – 18 Sep 29/9 – 2/10

Evolution Gr.11 content

• Plant hormones • Lamarckism • Artificial selection • Human Evolution • Revision of Human Revision • Plant defense • Darwinism • Speciation impact on the

mechanisms • Punctuated • Mechanisms of environment • Introduction to equilibrium reproductive Evolution • Natural isolation • Out of Africa • Variation Selection • Evolution in hypothesis PRELIM EXAMINATION present times SBA Practical Test term 3 task 3

(78%) (84%) (90%) (96%) (100%) WEEK 34 WEEK 35 WEEK 36 WEEK 37 WEEK 38 WEEK 39 WEEK 40 WEEK 41 WEEK 42 5 – 9 Oct 12 – 16 Oct 19 Oct – 2 Dec

REVISON REVISION FINAL EXAMINATION

In Life Sciences the last three levels are combined so that a FOUR level of cognitive demand is used:

Evaluating,

Applying scientific Knowing science Understanding analysing and knowledge science synthesising scientific knowledge 40% 25% 20% 15% To recall or To communicate To use, perform or Analyse complex recognise explicit understanding of a follow a basic/ information information, details, Life Sciences standard/ routine To adapt a variety of facts, formulas, concept, idea, procedure/rule/meth appropriate terms, definitions, explanation, model, od/ operation. strategies to solve or theory, for procedures, novel/ non- example to: representations from To use/apply routine/complex/ memory or from understanding of Interpret: change open-ended material provided. Life Sciences from one form of problems. To apply representation to concepts, facts or multi-step another (e.g. details from a known pictures to words; context to an procedures. words to pictures; unfamiliar context. numbers to words, Evaluate words to numbers, To evaluate or make pictures to numbers) critical judgement (for example, on Exemplify: Find a qualities of accuracy, specific example or consistency, illustration of a acceptability, concept or principle desirability, worth or

probability) using Classify: Determine background that something belongs to a knowledge of the category. subject. Judge, critique Summarize: Abstract a general Create a new theme or major product points. To integrate life

sciences concepts, Infer: Draw a logical conclusion from principles, ideas and presented information, make information. connections and relate parts of Compare: Detect material, ideas, similarities and information or differences between operations to one two objects or another and to an concepts. overall structure or

Explain why: create purpose. a cause-and-effect model of a system or concept.

DAY ONE

SESSION TIME ALLOCATION ACTIVITY RESOURCES

16:30 – 17:00 Plenary

SESSION 17:00 – 18:00 Registration of participants Registration forms

ONE Self-assessment – Pre-Test MCQ 18:00 – 18:30 Feedback on self-assessment

18:30 -19:00 Administration and logistical arrangements

19:00 – 21:00 DINNER

DAY TWO SESSION TIME ALLOCATION ACTIVITY RESOURCES

MODULE 1: DNA and PROTEIN SYNTHESIS Course material and video clip, Cell phones UNIT 1: How do we teach terminology? Laptop, internet Power Point Activity 1.1 Creating a cross word puzzle Presentation,

What types of nucleic acids are there Strawberries and what are their applications? * Zip-closure sandwich bags SESSION 08:00 – 10:30 Activity 1.2 DNA extraction * DNA extracting ONE solution (mix about 1 cup of dish washing liquid detergent and 1/4 cup salt into 4.5 litres of water) * Plastic cups * Gauze or cheesecloth * Rubber bands

* Test tubes * Droppers * Ice cold ethanol (place test tube of ethanol in a beaker containing ice cubes)

10:30 – 10:45 TEA BREAK

UNIT 2: Activity 1.3 and 1.4

UNIT 3: How does transcription and translation fit Course material SESSION Power Point 10:45 – 13:00 into protein synthesis? TWO Presentation Activity 1.5 Video clip

Activity 1.6

13:00 – 14:00 LUNCH BREAK

MODULE 2: MEIOSIS Course material UNIT 1: What is meiosis and where does it take SESSION Power Point 14:00 – 15:30 place? THREE Presentation Activity 2.1 Video clip Activity 2.2

15:30 – 15:45 TEA BREAK

Course material UNIT 2: What is non-disjunction and what are the consequences of it 16:00 – 18:00 Power Point Activity 2.3 Presentation

SESSION MODULE 3: REPRODUCTIVE STRATEGIES IN VERTEBRATES FOUR Course material UNIT 1: How do we teach terminology and Power Point 18:00 – 19:00 define the concepts of reproductive strategies? Presentation Activity 3.1 Video clip Activity 3.2

19:00 – 21:00 DINNER

DAY THREE SESSION TIME ALLOCATION ACTIVITY RESOURCES

Activity 3.3

Course material SESSION 08:00 – 10:30 Power point ONE Video clips

Structure of the male and female reproductive system

Activity 4.2

10:30 – 10:45 TEA BREAK

UNIT 3 – Puberty

UNIT 4 – Gametogenesis

Activity 4.3

UNIT 5 – Menstrual cycle Course material Activity 4.4 Power point SESSION 11:00 -13:30 UNIT 6 – Fertilization and development of the Video clip TWO zygote

UNIT 7 – Implantation, gestation and the role of the placenta

Activity 4.5

Self-evaluation – Post Test Post test Completion of evaluation forms

Graphically presented Feedback on Pre and Post test Closing

13:30 Plenary followed by Lunch

Module 1 DNA and Protein synthesis

DNA: THE CODE OF LIFE

INTRODUCTION

DNA is an important part of our make-up. The hereditary instruction carried within the DNA ensures that offspring resemble their parents and ensures that genetic variation can take place, resulting in survival of the fittest. The scientific field is doing on-going research on DNA and it has brought about a lot of new knowledge. Some examples of this are: the human genome project, DNA profiling, cloning, identifying the genes that are responsible for certain illnesses and isolating genes to correct mistakes in our genetic make-up. This topic is an important building block for the understanding of genetics and inheritance as well as evolution. It is important that learners understand this section well so that they could link it with the other topics that will be dealt with in the rest of the year.

OVERVIEW

This module deals with DNA and protein synthesis. The module starts with notes and important “tips” for learners. There is a detailed terminology list, followed by notes and hand-on activities.

SPECIFIC OBJECTIVES

By the end of this session, participants will be able to:

• Teach the terminology associated with DNA and protein synthesis • Create a crossword puzzle on line • Describe the structure of DNA and RNA structures • Perform a DNA extraction • Differentiate between DNA and RNA • Describe DNA replication • Differentiate between translation and transcription and explain the two processes • Discuss DNA profiling and its applications • Administer the Grade 12 Term 1 SBA task CONTENT

You will study this module through the following units:

Unit 1: How do we teach terminology? Unit 2: What types of nucleic acids are there and what are their applications? Unit 3: How do transcription and translation fit into protein synthesis?

How do we teach terminology?

DEFINITIONS AND IMPORTANT TERMS AND CONCEPTS:

STRATEGIES TO TEACH TERMINOLOGY 1. In every lesson identify new terms/concepts and write it on the board. 2. Learners will take down terms/concepts at the back of their notebooks noting the correct spelling. 3. Learners must define/write down the meaning of these words from listening to the educators lesson/finding meaning from the dictionary or textbook. 4. Break down the concept/term where possible- give the meaning of the prefix and suffix e.g. photo(light) synthesis(to build up). 5. Use the concept in a sentence. 6. Educator checks that learners have done the above, on a daily basis e.g. ask any learner to define a concept. 7. By the end of the year ALL learners have a comprehensive GLOSSARY of ALL terms /concepts. 8. ASSESSMENT: Biological terms to be included in all daily assessment tasks. Develop crossword puzzles. (Use various websites from internet e.g. eclipse) 9. Learning terminology also helps in answering MCQs and matching questions, etc.

Term Meaning/Definition

Base pairing Adenine (A) always bonds to thymine (T) and guanine (G) with cytosine (C) in DNA molecule, to ensure the precision of DNA replication

Chromatin Tangled network of chromosomes located within the nucleus

Chromatid The individual threads that form a chromosome

Centromere Structure joining two threads of a chromosome

Chromosome A structure made up of two chromatids joined by a centromere that carries the hereditary characteristics within the DNA Chromatin network Visible as thread-like structures in the nucleus of an inactive cell

Nucleolus Structure in the nucleus responsible for forming ribosomal RNA

Nucleoplasm That part of the protoplasm within the nucleus

Cytoplasm That part of the protoplasm outside the nucleus.

Ribosome Structure that is the site of protein synthesis

Gene Segment of a chromosome that controls each characteristic/ a unit of sequenced pieces of DNA that carry the genetic information that will determine the hereditary characteristics of an organism.

Hereditary Characteristics that are passed from parents to offspring

DNA Nucleic acid that is a constituent of chromosomes

Helix Natural shape of a DNA molecule

RNA Type of nucleic acid that occurs as a single strand / nucleic acid that contains uracil

Nucleotide Building blocks of nucleic acids consisting of a sugar, a base and a phosphate

Replication The formation of an exact copy of the DNA in a cell

Template The original strand upon which a new strand is developed

Complementary The new strand that is made based on the sequence of nucleotides on strand the template

Cytosine The base that pairs off with guanine

Thymine The base that pairs off with adenine

Uracil The base found in RNA and not DNA

Hydrogen bonds The chemical bonds which link base pairs in the DNA molecule

DNA: (Deoxyribonucleic acid) forms the chromosomes in the nuclei of all living cells and carries the hereditary information of the organism. The DNA molecule is a double helix (twisted) strand.

DNA Replication Process involving the formation of two new identical DNA molecules from an original DNA.

Enzyme A protein that speeds up a chemical reaction / a catalyst

Codon The three adjacent bases found on a DNA or m-RNA molecule

Anticodon The three adjacent bases found on a t-RNA molecule that will determine which amino acid will be brought to the ribosome

Transcription The synthesis of m-RNA from a DNA template

Translation The process of converting the information carried by m-RNA to the correct sequence of amino acids to form a particular protein

RNA (Ribose nucleic acid) a single strand, located in the nucleoplasm and cytoplasm. The RNA molecule is always a single strand of nucleotides. Remember that the RNA contains Uracil instead of Thymine (A, G, C and U). RNA is responsible for protein synthesis. Synthesis Building up of separate parts into a whole

Amino acid The basic building block of a protein molecule

Peptide link A link between two adjacent amino acids

Monomer A single unit that makes up a larger molecule

Polymer A large molecule which is formed from many small molecules (monomers)

Mutation A sudden and relatively permanent gene / chromosomal change

Mitochondrial DNA The type of DNA found only in the mitochondrion

Messenger RNA Responsible for carrying the genetic code that is transcribed from DNA, to (mRNA): specialized sites of the ribosomes where the information is translated for protein synthesis Nitrogenous bases: This is a nitrogen containing molecules viz. Adenine, (A); Thymine (T); Guanine (G); Cytosine (C) and Uracil (U). Nucleotide: The building block (monomers) of RNA and DNA. Each nucleotide consists of a pentose sugar, a phosphate ion and a nitrogenous base. Ribosomal RNA Form the ribosomes and produce the proteins, based on the information (rRNA) received from the tRNA

Transfer RNA (tRNA) Has anticodons, which codes for a specific amino acid. The anticodons are complementary to the mRNA codon, during the production of proteins. Genome All the genes present in an organism

ACTIVITY 1.1

AIM- To enable participants to create crossword puzzles on the internet in order to enforce terminology activities in class.

Background: Learners struggle with the terminology and teachers need to come up with fun ways to use terminology in class.

METHOD: The trainer will illustrate how to create your own crossword puzzle.

- Connect to the internet on you device

- Go to Google and enter crossword puzzle maker

- Choose the option:

- Make your own printable crossword puzzles/A to Z teacher stuff tools

- Follow the instructions on the page

Reflection: There are many websites that could be used to create crossword puzzles.

TheTeachersCorner.net

Atozteacherstuff.com

What types of nucleic acids are there and what are their applications?

1. DNA and where it is found

In the nucleus of almost every cell in your body is the collection of DNA needed to make you. DNA in the nucleus is grouped into 23 sets of chromosomes that are called your genome. DNA is grouped into groups called genes within each chromosome. Your genome contains about 35000 genes. Some interesting facts regarding chromosomes:

 Chromosome 1 is the largest chromosome with roughly 250 million nucleotide base pairs, and 4316 genes have been identified on this chromosome. If we could stretch out this chromosome it would be 8.5 cm. 890 diseases are linked to this chromosome (Alzheimer's type 4, breast cancer etc.)

 Chromosome 21 is the smallest with roughly 48 million nucleotide base pairs, with between 477-635 genes. Diseases related to genes on chromosome 21 are Alzheimer, lateral sclerosis, Down syndrome, certain types of deafness and 8 other identified syndromes.

Following is a diagram illustrating where DNA is found in a cell:

ACTIVITY 1.2

AIM- To enable participants to extract DNA from a given fruit. BACKGROUND: Teachers need to do the practicals provided in their resource cd’s. METHOD: Participants should be divided in groups of 5 members. Each group should collect the materials listed below and follow the method stated.

Materials

* Strawberries * Zip-closure sandwich bags * DNA extracting solution (mix about 1 cup of dish washing liquid detergent and 1/4 cup salt into 4.5 litres of water) * Plastic cups * Gauze or cheesecloth * Rubber bands * Test tubes * Droppers * Ice cold ethanol (place test tube of ethanol in a beaker containing ice cubes)

Procedure

1. Place a strawberry in a zip-closure bag and remove most of the air before you seal the bag. 2. Mash the strawberry through the bag in your hand. Do not hit against the table. 3. Add 2 tablespoons of the DNA extracting solution 4. Continue mixing and mashing the bag in your hand. 5. Place a piece of gauze over the opening of the cup and secure with a rubber band. 6. Carefully pour the strawberry mixture into the cup making sure to catch the solids with the gauze. 7. Take a dropper full of the liquid in the cup and place it in the test tube. 8. Add a dropper full of the methylated spirits the test tube. 9. DO NOT tilt or tip the test tube; DO NOT mix the two liquids. 9. Observe the line between the strawberry mixture and the ice cold ethanol. 10 You will notice a white thread-like cloud appearing at this line.

This is strawberry DNA. The DNA will clump together and float to the top of the alcohol layer.

REFLECTION ON ACTIVITY:

1. Why do we use the dishwashing liquid? 2. Why do we use the salt? 3. What does the alcohol contribute to the experiment?

The Structure of DNA

Each nucleic acid consists of a number of basic building blocks called nucleotides. Each nucleotide consists of three parts: 1 phosphate ion, 1 pentose sugar and 1 nitrogenous base.

The structure of a nucleotide:

phosphate

ion

pentose nitrogenous base sugar

 The phosphate and sugar form the backbone of the DNA molecule, whereas the bases form the “rings”.  There are four types of nitrogenous bases. - Thymine - Guanine - Cytosine - Adenine

Combination is ALWAYS:

Guanine Cytosine

Adenine Thymine

 A gene is a section of DNA that codes for a protein.  Each unique gene has a uniqueAdenine sequence Thymine of bases.  This unique sequence of bases will code for the production of a unique protein.

 It is these proteins and combination of proteins that give us a unique phenotype.

ACTIVITY 1.3

AIM- To enable participants to identify different parts of the DNA structure. BACKGROUND: Teachers need to use creative ways to teach these abstract concepts to learners METHOD: Use the template below and build a DNA molecule. The sequence of the left hand strand Is as follow:

TAG-CGG-AAG Paste your molecule on your page and label the structure.

REFLECTION: Will you be able to use this activity in your classroom? Would you modify it and how?

2. DNA REPLICATION:

1. The double DNA helix unwinds. 2. Weak hydrogen bonds between nitrogenous bases break and two DNA strands unzip

(separate). 3. Each original DNA strand serves as a template on which its complement is built. 4. Free nucleotides build a DNA strand onto each of the original two DNA strands by

attaching to their complementary nitrogenous bases (A to T and C to G) 5. This results in two identical DNA molecules. Each molecule consists of one original strand and one new strand

Step 1: DNA molecule unwinds (unzip)

Enzyme that “unzips” helix is DNA helicase

Step 2: New bases attach themselves

New bases attached themselves in Free nucleotides in the correct place nucleoplasm of each strand

Step 3: Two identical strands are formed. Each strand now becomes a double helix. Strand 1 Strand 2

The significance of DNA replication: • Important for growth and reparation • Mutations in DNA could cause genetic variation.

3. DNA PROFILING What is DNA profiling? A technique used by scientists to distinguish between individuals of the same species using only samples of their DNA. The process is as follow:

- The nucleotides are separated from each other in the order that they are found in a strand of DNA - Nucleotides appear as dark bands - The sequence of the bases in this segment is identified - Use as DNA fingerprint - Unique for every person

What is DNA profiling used for: Solving crimes Paternity tests Identifying bodies

The process followed in paternity cases are: 1.The potential father, mother and child’s DNA profiles are compared next to each other. (All three persons’ DNA bands are on same diagram). 2. Eliminate all the bands that match the mother. 3. All the remaining bands are compared to the father and if all the remaining bands correspond with the DNA bands of the potential father , he is the biological father.

Below are six different persons’ DNA profiles depicted with the dark bands. You can see who is related by using a ruler to see which bands correspond with each other. There are twins here; can you see who are twins?

Solving crimes by using a DNA fingerprint:

• A useful but controversial method. • A sample of a suspect’s bodily fluid or tissue is to be compared with a sample found at the scene of a crime. • The pattern of lines represents a person’s specific genetic make-up. • DNA fingerprinting used in 11/9 disaster to identify victims.

4. RNA

There are three types of RNA molecules, namely messenger RNA (mRNA); transfer RNA (tRNA) and ribosomal RNA (rRNA).

1. Messenger RNA (mRNA) Has the same sequence of bases as the DNA strand that has the gene sequence. Acts as a template for protein synthesis.

2. Transfer RNA (tRNA) One for each triplet codon that codes for a specific amino acid. tRNA molecules are covalently attached to the corresponding amino acid at one end. At the other end they have a triplet sequence (called the anti-codon) that is complementary to the triplet codon on the mRNA.

3. Ribosomal RNA (rRNA) Make up an integral part of the ribosome, the protein synthesis machinery in the cell. (Not examinable).

Differences between the different nucleic acids:

ACTIVITY 1.4

AIM- To enable participants to identify different parts of the DNA structure, answer questions pertaining to DNA profiling and distinguish between DNA and RNA structure. BACKGROUND: DNA and RNA molecules form an integral part in protein synthesis, it is important that learners know the difference. METHOD: Answer the following questions.

1..1 The diagram below represents a process involving DNA.

1.1.1 Identify the process illustrated in the diagram above. (1)

1.1.2 Identify the monomer X. (1)

1.1.3 Using the key provided, give the names for 1 and 2 respectively. (2)

1.1.4 What is the natural shape of the molecule represented? (1)

1.1.5 Name the type of bond that is formed between 1 and 2. (1)

1.2 A freshly smoked cigarette was found near the body of a murdered woman. Forensic specialists made a DNA profile from traces of saliva (not belonging to the murdered victim) found on the cigarette. Four suspects were required to give DNA samples to forensic officers and the following profiles were made:

Saliva

Who is most likely the murderer?

A Ben B Jane C Adam

D Donald

1.3 Tabulate the differences between DNA and RNA

UNIT 3: How do transcription and translation fit into protein synthesis?

1. The importance of proteins:

 Play essential roles in the cells of all living creatures.  They serve as building blocks of cells, control chemical reactions, and transport materials to and from cells.  Composed of long chains of amino acids.  The specific sequence of amino acids in a chain determines the exact function of the protein.

2. The process of protein synthesis

Protein synthesis takes place in two steps namely transcription and translation. The two steps will now be dealt with in detail.

Transcription:

• Takes place in the nucleus • Double stranded DNA unzips • When the weak hydrogen bonds break • One strand is used as a template • To form mRNA • Using free mRNA nucleotides from the nucleoplasm • mRNA is complementary to the DNA • mRNA moves from the nucleus to the cytoplasm and attaches to the ribosome

REMEMBER: DNA RNA T – A U – A G – C G - C

mRNA

DNA template free mRNA nucleotides from the nucleoplasm

Translation:

• Takes place in cytoplasm • Each tRNA carries a specific amino acid • When the anticodon on the tRNA • Matches the codon on the mRNA • Then tRNA brings required amino acid the ribosome • Amino acids become attached by peptide bonds • To form the required protein

mRNA

Amino acids become attached by peptide bond

Each protein is formed specifically to the genetic code stored on the DNA in the nucleus of every cell in the organism. Any change during this coding process will result in a gene mutation.

The following table indicates how an amino acid’s anticodon on the tRNA, codon on the mRNA and base triplet on DNA are related. Note the difference regarding the thymine and uracil.

Amino Acid Base triplet of DNA Codon of mRNA Anticodon of tRNA

* Contains Thymine * Each Codon is * Each Anticodon is not Uracil complementary complementary (opposite) to the DNA (opposite) to the Codon base triplet but and similar to the DNA contains Uracil – not base triplet but contains Thymine Uracil – not Thymine

Alanine CGA GCU CGA

Histidine GTC CAG GUC

Valine CAT GUA CAU

Serine AGA UCU AGA

ACTIVITY 1.5

AIM: To practice the difference in transcription and translation. BACKGROUND: The application of translation and transcription is tested in the examinations and learners need to be able to do both. Method: Follow the steps in number 1 in order to build a protein synthesis “cupboard” and answer question 2. 1. Use an A4 piece of paper. Fold it like a cupboard

Fill in the left side as illustrated in the next photo:

This is the DNA template strand. Open the right hand flap and fill in the complimentary mRNA bases.

After you have done this, open the left hand flap and fill in the tRNA complementary bases.

Lastly, return to front right hand flap and complete the right hand of the DNA strand.

Reflection on activity Lead learners to see that tRNA corresponds with the DNA template strand, the only difference is that thiamine is replaced with uracil. You could bring in a mutation here as well; if one code is incorrectly transcribed then the anticodon will be wrong/ changed. Discuss any other additions to this method.

ACTIVITY 1.6

AIM: To practice the SBA before the learners have to do it. Method: Follow the instructions below:

This task consists of three sections: - A hands-on activity on protein synthesis, - A worksheet on the structure of DNA - A worksheet on protein synthesis.

Note to teacher: ALL SECTIONS MUST BE COMPLETED INDIVIDUALLY UNDER SUPERVISED CONDITIONS IN THE CLASSROOM.

SECTION A

How DNA controls the workings of a cell

A gene is a segment of DNA that provides the instructions for making a protein and proteins influence our characteristics (the way we look). Thus, each gene contains a specific

sequence of nucleotides which gives the instructions for the specific sequence of amino acids that will be joined together to form a protein. The sequence of amino acids in the protein determines the structure and function of the protein.

Protein synthesis – A Polypeptide Activity

1. Materials • A2 paper (Paste 4 A4 sheets together) • Scissors • Cellotape • Glue • Colouring pencils (optional) • Attachments: nucleus, cytoplasm, ribosome, DNA, mRNA, tRNA, amino acids, peptide bonds, amino acid codon chart.

2. Instructions

Individual work only

1. Choose one of the four DNA codes on page 4. You will therefore make ONE polypeptide chain.

2. Use the different parts and words from the attachments supplied to you (pages 3 – 5) to illustrate the process of protein synthesis. Look at the A2 paper and decide where you will place the nucleus, cytoplasm and ribosome. Use a scissor to cut them out but do not paste them down yet.

3. Go to the nucleus with the mRNA paper strips and transcribe the DNA code from the nucleus to the mRNA molecule. Place the mRNA code next to the DNA. Place another copy of the mRNA at the ribosome. (You will therefore make two exact copies of mRNA)

4. Translate the code on the codon and write the anti-codon on the bottom of each tRNA molecule. Place the tRNA anti-codons in the correct sequence underneath the mRNA on the A2 paper.

5. Use the codon chart to look up the amino acids represented by each anti-codon.

6. Place the amino acids in their correct sequence next to each other (underneath the anti-codons) to form a polypeptide chain.

7. Paste everything down. Supply labels.

8. Write your name and date at the back of the A2 sheet and hand in for assessment by your teacher. (10)

SECTION B

DNA Structure: Complete all answers on this worksheet

QUESTION 1 The diagram below shows the structure of a DNA molecule. Study the structure and answer the questions that follow.

1.1 On the diagram above:

• Circle and label a nucleotide. (1)

• Label the sugar and phosphate molecules. (2)

• Label the bases that are not already labeled. (2)

• Label a base pair. (1) • Label the sugar – phosphate backbones. (1)

• Label the weak hydrogen bonds. (1)

1.2 In a strand of DNA, if the percentage of thymine is 30%, what would the percentage of cytosine in the same DNA strand be?

______(2)

(10)

SECTION C

QUESTION 2

Gene to Protein Below are two partial sequences of DNA bases (shown for only one strand of DNA). Sequence 1 is from a human and sequence 2 is from a cow. In both humans and cows, this sequence is part of a set of instructions for controlling a bodily function. In this case, the sequence contains the gene to make the protein insulin. Insulin is necessary for the uptake of sugar from the blood.

DNA sequence 1: Human

CCA TAG CAC GTA TGA TAA

DNA sequence 2: Cow

CCG TAG CAT GTT TGA CAC

2.1. Comparing the human gene to the cow gene, how many codons are exactly in the same sequence?

______(1)

2.2. Use the cow sequence and write down the tRNA anti-codons.

______(1) 2.3. How many amino acids in the Human are in the same sequence as in the Cow? (Use the codon chart on page 6).

______(2)

2.4 Fill in the complimentary DNA strand below using DNA base pairing rules. (2)

2.5 Fill in the correct mRNA bases by transcribing the DNA template strand in question 2.4. (2)

2.6 Translate the mRNA codons (Question 2.5) and find the correct amino acid using the Amino acid codon table on page 6. Write the amino acids in the large circles below.

(2) (10) TOTAL: 30

REFLECTION ON ACTIVITY:

How would you administer this SBA? What precautions do you need to implement before you administer the SBA?

RESOURCE http://www.amoebasisters.com/handouts. https://bbsrc.ukri.org/documents/fullbooklet-pdf/ https://dnatest.co.za

MODULE SUMMARY

This topic is an important building block for the understanding of genetics and inheritance as well as evolution. It is important that learners understand this section well so that they could link it with the other topics that will be dealt with in the rest of the year.

The following points are important to remember:

• The structures of DNA and RNA is NB • The differences between DNA, mRNA and tRNA are important. • DNA profiling is important for application questions. • DNA replication and transcription are confused - ensure differentiated understanding. • Transcription and translation must be learnt by heart.

REFERENCES

• DBE Exam guidelines for learners • GDE ATP • 2015-2019 NSC past papers • 2014-2018 national diagnostic report on learner performance • Approved grade 12 national textbooks • ‘Mind the Gap’

MODULE 2 MEIOSIS

INTRODUCTION

Two types of cell division occur in organisms, namely mitosis and meiosis. During mitosis cells make exacts copies of themselves.

Meiosis usually takes place in the reproductive organs (in animals) to produce gametes. During this cell division, the diploid chromosome number is halved. Meiosis takes place in two phases. (Cell division takes place twice). The resulting cells will have chromosomes that are hybrids because genetic recombination occurs during meiosis. Meiosis is important in sexual reproduction as it involves the combination of genetic information from both parents. This process allows cells to have half the number of chromosomes, so two of these cells can come back together to form a new organism with the complete number of chromosomes. It not only helps produce gametes, it also ensures genetic variation.

OVERVIEW

This module deals with Meiosis. The module starts with a terminology list associated with the topic Meiosis. The process of Meiosis is explained using diagrams (which the examiners normally do to set questions on this topic in the national papers). Notes, hand-on activities, karyographs and micrographs supported by video clips are also included.

SPECIFIC OBJECTIVES

By the end of this session, participants will be able to:

• Teach the terms associated with meiosis • Indicate where meiosis take place in animals and plants • Discuss and interpret the process of meiosis • Explain the process of non-disjunction and interpret it from karyographs and other diagrams • Explain Down syndrome

CONTENT

You will study this module through the following units:

Unit 1: What is meiosis and where does it take place? Unit 2: What is non-disjunction and what are the consequences of this?

UNIT 1: What is meiosis and where does it take place?

TERMINOLOGY:

Autosomes: Chromosomes that are not sex chromosome. There are 22 pairs of autosomes in a diploid cell.

Bivalent A pair of homologous chromosomes physically held together by at least one DNA crossover.

Centriole: An organelle in the cytoplasm of the cell, which gives rise to spindle fibres during meiosis and mitosis.

Centromere: Structure that holds two chromatids together to form a chromosome.

Chiasma: Point where crossing over takes place between chromatids of the homologous chromosome during prophase 1.

Chromatid: It is a single thread of a double stranded chromosome. Two chromatids are joined by a centromere to form a chromosome.

Chromosome: A structure made up of two chromatids joined by a centromere that carries the hereditary characteristics within the DNA.

Diploid number (2n): Complete chromosomal number represented in pairs, which is characteristic of an organism.

Gametes: Haploid cells (n) which contain half the chromosome number of the diploid generation. Egg cells and sperm cells are the gametes necessary in sexual reproduction where the fusion of the two gametes results in a new individual.

Gene: The unit of heredity transmitted in the chromosome, which controls the development of the characteristics.

Gonosomes: Sex chromosomes. There is one pair of sex chromosomes in a diploid cell: the XX chromosomes in females and XY chromosomes in males.

Haploid number (n): Half the number of chromosomes present in gametes after meiosis has occurred.

Homologous Maternal and paternal chromosomes having the same shape and size which are chromosomes: paired but differs in genetic material.

Maternal: From the mother / female parent.

Meiosis: A process of cell division whereby the chromosomal number is halved for the production of haploid gametes (sperm cells and egg cells).

Mitosis: A process of cell division where the resulting daughter cells have the same diploid chromosomal number as the original parent cell.

Non-disjunction: The homologous chromosomes do not separate due to failure of the centromere to divide during meiosis I & II. The resulting gametes will have either an extra chromosome/copy or another gamete will have one less chromosome.

Paternal: From the father / male parent.

Somatic cells: Normal diploid body cells.

Spindle fibres: Micro-tubules that form during cell division which radiate out from the centrosomes and draw the chromosomes to the poles.

Variation: The morphological and physiological differences that can be seen between members of the same species.

Zygote: The resulting diploid cell after fertilization has occurred

ACTIVITY 2.1

AIM: An alternative approach to terminology

Background: Learners struggle with terminology

Method: Find the words in the wordlist:

Where does meiosis take place in animals?

Meiosis usually takes place in the reproductive organs of animals. The following diagrams illustrate where it takes place in males and females.

In men meiosis takes place in the testis and in women in the ovary as well as the fallopian tube.

Where does meiosis take place in plants?

In plants meiosis takes place during the production of spores. It usually takes place in the anther and ovule in flowering plants. The following diagram shows where meiosis takes place in plants.

Structure of a chromosome

It is important to know what a chromosome is and what the difference between a replicated and unreplicated chromosome. The diagram below illustrates the structure of chromosomes. It starts at DNA level and shows how DNA is supercoiled to form a chromosome.

DNA replication

Replication takes place during interphase where two copies of the chromosome is made. Each copy is now called a chromatid which is joined by a centromere. This is illustrated by the diagram below:

Single chromosome before Double chromosome with two chromatids replication in interphase after DNA replication

Chromosome number

• Every species has a specific number of chromosomes in the nucleus. • Somatic cells (body cells) have the diploid number (2n) (equal amount of chromosomes). • There are two chromosomes of each kind, one from the mother and one from the father. • Sex cells (gametes) contain only half the number of chromosomes (n). • When a female (n) gamete and a male gamete (n) fuse the resultant zygote is diploid (2n). • Human somatic cells have 46 chromosomes in the nuclei and gametes have 23 chromosomes.

The process of meiosis

Stages of meiosis

Meiosis 1

Prophase 1

1. Chromosomes shorten and become visible as two chromatids joined by a centromere. 2. Homologous pairs of chromosomes are now visible. 3. The nuclear membrane and nucleolus disappear. 4. The spindle starts to form. 5. Chromatids from each homologous pair touch. The point where they touch

is called a chiasma. 6. DNA is crossed over (swopped) at the chiasma.

Metaphase 1

______

1. The spindle extends across the whole cell. 2. The homologous chromosomes line up along the equator of the spindle in their homologous pairs. 3. One chromosome of each pair lies on either side of the equator. Random arrangement takes place. 4. The centromere of each chromosome attaches to the spindle fibres.

______

Anaphase 1

1. Chromosomes- move to opposite sides of the cell, spindle fibers shorten. 2. Cell begins to split: a furrow forms in animal cells; a cell plate forms in plant cells. Telophase 1

Telophase 1 1 .The nuclear membrane re-forms around the chromosomes. 2. The nucleolus reforms. 3. Each pole has half the number of chromosomes present in the

original cell. 4. The cell membrane constricts and divides the cytoplasm in half to form two cells.

MEIOSIS II

Prophase 2

1. Centrioles move to opposite sides in an animal cell. 2. Nuclear membrane and nucleolus disintegrate. 3. Chromosomes formed with 2 chromatids. 4. At the very end of prophase, the spindle forms.

______

Metaphase 2

1. Centromeres, which hold the chromatids together, attach to spindle fibers. 2. Chromatids line up across the equator of the cell.

______

Anaphase 2

1. Centromeres split and chromatids move to opposite sides of the cell 2. Cell begins to split: a furrow forms in animal cells; a cell plate forms in plant cells.

______

Telophase 2

1. The nuclear membrane re-forms around the single stranded chromosomes. 2. The nucleolus reforms. 3. The cell splits into four haploid sister cells.

______

The difference between meiosis and mitosis:

MITOSIS MEIOSIS

Site where it occurs Somatic cells Ovaries and testis (Animals)

Ovules & anthers (Plants)

Purpose of process Growth Formation of haploid gametes

No. of daughter cells Two identical cells 4 haploid cells genetically different produced

No. of divisions One nuclear division Two nuclear divisions

Activity 2.2

AIM: Creative activity to enhance the teaching of meiosis.

Background: Meiosis is an abstract process and learners need to be exposed to different methods of learning it.

Method: follow the instructions below.

QUESTION 1: Puzzle Activity Materials required:

1. 2 x sheets with puzzle pieces 2. Pair of scissors 3. Glue or cellotape 4. Pen, pencil, ruler, eraser

1.1. Cut out each puzzle piece. Build the puzzle so that each piece fits in the correct position. Stick these pieces onto a blank folio page provided. (1)

1.2 Provide a caption for your puzzle. (1)

1.3 Label all the phases on the puzzle. (2)

1.4.Fill in the following labels of structures/processes found in your puzzle:

• Centriole • Spindle fibres

• Centrosome • Homologous chromosomes • Chiasma

• Crossing over • Chromatid

• Daughter chromosomes (4)

1.5. At which phase do the cells formed become haploid? (1)

1.6. Give one reason for your answer to QUESTION 1.5 (1)

1.7. From the puzzle, state how many chromosomes occur in one cell in… (1) 1. The first stage of meiosis (1) 2. The last stage of meiosis

2. The graph below shows varying amounts of DNA in the nucleus of a cell during the cell cycle.

DNA content per nucleus nucleus content per DNA

Time

2.1 Which type of cell division is illustrated in the graph above? (1)

2.2 Which phase occurs between points 1 and 2? (1)

2.3 Describe the decrease in DNA content per nucleus…

1. between points 2 and 3. (2) 2. between points 3 and 4. (2)

3 PRACTICAL WORKSHEET 2

Practical: Observe micrographs in selected stages of meiotic cell division

Procedures: Examine the micrographs which show the various stages of meiosis. Note the

micrographs are not in the correct sequence in which they occur when the process of meiosis takes place.

Micrograph A Micrograph B

Micrograph D Micrograph C

Observations:

1. Write down the numbers 1.1 to 1.8 and next to each, the answer that will best

complete the table below:

Micrograph Name of Phase Reason for Identification

A 1.1 1.2

B 1.3 1.4

C 1.5 1.6

D 1.7 1.8

2. Arrange the letters of the diagrams in the order that they occur during the

process of meiosis :

______

3. Make a fully labelled drawing of the cell shown in micrograph A

4. State TWO places where the process will take place in:

(A) plants

______

(B) animals

______

5. How many daughter cells can be observed at the end of the process?

______

6. What do the cells in diagram D form?

______

7. What is the importance of meiosis?

______

Reflection on activity:

What preparation will be needed for the puzzle activity? What other methods would you use to teach meiosis.

UNIT 2: What is non-disjunction and what are the consequences of this?

The homologous chromosomes do not separate due to failure of the centromere to divide during meiosis I & II. This usually happens during anaphase 1 or 2. The resulting gametes will have either an extra chromosome/copy on chromosome pair or another gamete will have one less chromosome.

The following diagram illustrates how non-disjunction takes place.

Down syndrome

The condition is named after Dr Down who described it the first time in 1866. People with Down syndrome have 47 chromosomes instead of 46 because the 21st set of chromosomes did not divide properly during anaphase 1 in oogenesis. Both chromosomes of the homologous pair then end up in one ovum (which now has 24 chromosomes). If fertilisation takes place, the resulting zygote will have 47 instead of 46 chromosomes. This condition is called trisomy 21, because there are three (tri) chromosomes on the 21st pair of chromosomes.

Karyotype is the number and visual appearance of the chromosomes in the cell nuclei of an organism or species. It is an individual's collection of chromosomes. This is sometimes used by examiners to ask

questions about Down syndrome. The following images illustrate the differences between normal karyotypes and the karyotype of a woman with Down syndrome.

The first 22 pairs of chromosomes are non-sex chromosomes and are called autosomes. The 23rd pair of chromosomes is sex chromosomes, also known as gonosomes. They are composed of one large X and one small Y chromosome in the case of males or two large X chromosomes in the case of females.

In the Down syndrome karyotype one can clearly see that there are three chromosomes at position 21 instead of only two as the karyotypes of the normal male and female above indicate.

Activity 2.3

AIM: To answer exam based questions on non-disjunction Background: Non-disjunction is asked using different kind of diagrams expecting learners to apply their knowledge. Method: Answer the question below:

Sometimes an error occurs in oogenesis resulting in an ovum which carries an extra chromosome. Part of such a process is shown in the diagram below.

1.1 Name stage 1 in this diagram. (1) 1.2 Identify the error that resulted in ovum R. (1) 1.3 How many gonosomes are there in the diploid cell? (1) 1.4 If ovum S is fertilised by a normal sperm: (a) What will be the number of chromosomes in the zygote? (1) (b) What genetic disorder will result? (1)

2. Study the diagram below and answer the questions that follow:

2.1. What is this type of diagram called? 2.2. What is represented in this diagram? 2.3. Name the syndrome that the individual is suffering from. 2.4. What error gave rise to this syndrome? 2.5. Describe how this syndrome is caused.

Reflection on activity Which method would you use to teach non-disjunction and Down syndrome? RESOURCE https://www.khanacademy.org/science/biology https://www.yourgenome.org/facts/what-is-meiosis https://www.thoughtco.com/differences-between-mitosis-and-meiosis-373390

MODULE SUMMARY

This topic is assessed in both Life Sciences papers and therefor it is important to note the following subtopics:

• The differences between mitosis and meiosis are important. • The difference between unreplicated and replicated chromosomes. • The process of meiosis (phase 1 and 2) and the differences. • Non-disjunction and its consequences. • Diagrams play a very important role in this topic.

REFERENCES

Module 3 Reproductive strategies in Vertebrates

INTRODUCTION

Reproductive strategies represent a set of behavioural, morphological, and physiological adaptations that facilitate access to potential mates, improve the chances of mating and fertilization, and enhance infant survival.

OVERVIEW

This module deals with reproductive strategies in vertebrates and how these strategies ensure survival of the species. The module starts with notes and important “tips” for learners. There is a detailed terminology list, followed by notes on the following topics: internal vs external fertilization; types of reproduction: ovipary, ovovivipary and vivipary; the amniotic egg and types of development: precocial and altricial and parental care

SPECIFIC OBJECTIVES

By the end of this session, participants will be able to:

• Teach the terminology associated with reproductive strategies in vertebrates • Apply knowledge of the concepts to case studies. CONTENT

You will study this module through the following units:

Unit 1: How do we teach terminology and define the concepts of reproductive strategies? Unit 2: External and internal fertilization Unit 3: Ovipary, ovovivipary and vivipary Unit 4: Amniotic egg Unit 5: Precocial and altricial development Unit 6: Parental care

IMPORTANT notes:

• Learners MUST understand the link between reproduction and continuation of the species. • There are several strategies that animals use to ensure successful reproduction so that the species can endure. • Learners MUST have a clear understanding of the terminology in order to study reproductive strategies • Although this topic only has a few marks in the exam the type of questions are not always linked to terminology. In recent years data-based questions based on this topic have been included in exams and therefore it is important that learners know and understand the concepts and can apply this knowledge in case studies. • The main types of questions based on this topic are :

- Terminology

- Amniotic egg

- Courtship behaviours

- Types of reproduction

How do we teach terminology and define the concepts of reproduction in animals

DEFINITIONS AND IMPORTANT TERMS AND CONCEPTS

Biological term Description

Allantois The structure in the amniotic egg that stores wastes The reproductive strategy when hatchlings of birds are not able to move Altricial development and feed themselves A type of egg where the embryo develops inside a fluid-filled sac Amniotic egg which is surrounded by a shell A type of fertilisation in which the nucleus of a sperm fuses with the External fertilisation nucleus of an ovum outside the body of the female A type of fertilisation in which the nucleus of a sperm fuses with the Internal fertilisation nucleus of an ovum inside the reproductive system of the female Ovipary The reproductive strategy involving the laying of eggs Producing young by means of eggs which are hatched within the body of Ovovivipary the parent The reproductive strategy when hatchlings of birds are able to move and Precocial development feed themselves A type of reproduction in humans where the foetus develops inside the Vivipary uterus Zygote The diploid cell formed by the process of fertilisation

ACTIVITY 3.1

AIM: To enable participants to create crossword puzzles or word search on the internet in order to enforce terminology activities in class

METHOD: complete the following crossword puzzle. The facilitator will then illustrate how to create your own crossword puzzle word search and word scramble , afterwhich you will then try to do it yourself

WHAT IS A REPRODUCTIVE STRATEGY?

Animals have a variety of behaviour and ways to ensure that they are successful in reproducing in different environments, which makes them successful in the habitat in which they live.

Reproduction is the production of a new generation of organisms from an existing generation. It involves firstly the production of young, and then the growth and development of the young into mature adults. Reproduction is a life process that ensures the continued survival of a population.

Activity 3.2

AIM: to link the advantage of each strategy to the survival of the species

Method: complete the table below:

EXTERNAL FERTILIZATION

• The sperm cell fuses with the egg cell outside the body of the female. • The sperm cells are discharged (released) directly into water. • Examples are aquatic animals like frogs, sponges, jellyfish, worms and fish. • A mass of amphibian eggs, appearing as small black spots, is contained within a gelatinous mass while they incubate in a freshwater pond. • Eggs deposited in this fashion receive little or no parental protection and will soon hatch into small, wriggling tadpoles.

ADVANTAGES DISADVANTAGES • No additional energy is needed for • Chances are very slim for a sperm parental care or formation of a cell to meet the ova of the same protective layer. species. • No need for a male to have a • Predators eat the sperm and ova special organ to insert the sperm before fertilization can occur. into the female’s body. • Strong currents carry sperm cells • Chances of fertilisation are away before fertilization can occur. enhanced by courtship display by • Reproduction must take place in fish. water otherwise gametes or • Does not use much energy. fertilized eggs will dehydrate.

INTERNAL FERTILIZATION

• The sperm cell from the male is transferred into the female by copulation (sexual intercourse). • The sperm cell then fuses with the ovum inside the body of the female. • Examples : terrestrial mammals, birds and insects. • Terrestrial vertebrates clasp each other tightly during copulation. • The male deposits his sperm into the female’s reproductive tract. • For the giant Galápagos tortoises mating may take hours and is initiated by the male, who bangs his shell against that of the female to get her attention. • These animals mate in the spring.

ADVANTAGES DISADVANTAGES • Ensures that the sperm cell comes • Fewer eggs are produced. into contact with the ovum. • The animal must have a copulatory • Developing embryo is protected organ to insert the sperm cells into from predators the female body.

• and removed from harsh environments.

Types of Reproduction

OVIPARY

• Refers to egg laying animals. • Eggs are protected by a hard shell, while others are protected by a jelly like layer after fertilisation. • Development does not occur inside the body. • The development of an organism is completed inside the egg after it has been laid. • Examples: frogs, insects, birds, and marine animals.

ADVANTAGES DISADVANTAGES • Eggs and sperm cells are produced in • Mortality rate is high. large numbers to increase chances of survival to adulthood. • Much energy is invested for parental care. • Parental care ensures survival to adulthood.

OVOVIVIPARY • Animals that do not lay eggs but keep them in their bodies until they hatch. • The body temperature is necessary for them to hatch. • There is no connection between the embryo and the mother. • Examples: sharks, lizards, cockroaches and some snakes. • Advantages : • The young one is protected from cold and predators to ensure survival. • The young one can develop to a fairly large size before birth. • Among some snake species, females bear live young. • This method of reproduction may be beneficial to snakes that live in cold climates, because the pregnant female can bask in the sun to keep her developing offspring warm.

VIVIPARY • Refers to animals that give birth to live young ones. • There is a connection between the developing foetus and the mother. • Examples: most mammals like human beings, whales and kangaroos.

ADVANTAGES DISADVANTAGES • The temperature is regulated by the • Number of off springs produced is mother. few. • The mother provides nutrition for • More energy is used to provide parental care. the young one.

• Mortality rate is lower. • Parental care ensures survival to adulthood.

Activity 3.3

AIM: To enable participants to apply the concepts to a case study

Method: Complete the following questions:

(DBE, June 2017, Paper 1)

Q3. Study the diagram of one-day-old hatchlings A and B below. The diagram is not drawn to scale.

Egg shell B

A Egg shell

3.1 State TWO visible features in hatchling A which indicate altricial development. (2)

3.2 The diagram represents ovipary.

Explain ONE possible advantage of vivipary when compared to ovipary. (2)

3.3 Explain why you would expect that the yolk content of the egg of hatchling B was more than that of hatchling A. (2)

(North West, June 2016)

Q1. The diagram shows a male seahorse. A seahorse is a fish. During reproduction the female seahorse transfers her unfertilized eggs to the male’s pouch. The male seahorse then fertilizes the eggs while they are inside his pouch. The fertilized eggs stay in the pouch where they develop into young seahorses.

pouch

A scientist states that a seahorse is ovoviviparous. Explain why this statement does not fit the normal definition of ovoviviparous. (5)

Amniotic egg

AMNIOTIC EGG

• This is the egg laid by reptiles, birds and some mammals. • The embryo develops inside the amnion and is protected by many membranes and hard shell. • Amniotic fluid protects the embryo from drying out. • It feeds from the yolk. • The allantois removes metabolic wastes. • The chorion supplies oxygen, food and water. • Advantages : • They are resistant to dryness.

• Oviparous animals can move into VARIOUS environments. • Is protected by a number of membranes. • This complicated structure can allow animals to evolve into bigger forms, and better protect themselves.

EVOLUTIONARY ADVANTAGE

• A critical evolutionary development for terrestrial animals is the reptilian amniotic egg, now also characteristic of birds and some mammals. • The developing embryo, protected from drying out, can survive out of water and in a variety of habitats. • The yolk provides it with food, and the albumen supplies water and nutrients. • Wastes are released to the allantois, an extension of the embryonic gut. • Oxygen diffuses easily through the thin outer shell of the egg; its passage to the embryo is regulated by the chorion.

Precocial and altricial development

PRECOCIAL DEVELOPMENT

• Young ones are relatively mature and are able to move around after they are born or hatch. • Their eyes are open, and have good eyesight. • They can go out to search food for themselves. • Have a strong skeleton, and their body is either covered by feathers (birds) or hair (mammals). • Birds need their parents to keep them warm, but this lasts for a short period. • Mammals can regulate their body temperature. • Examples: birds, cattle, sheep, antelopes, buffalo, elephants, hippos and giraffe.

ALTRICIAL DEVELOPMENT • Young ones are unable to move after birth and are helpless. • They do not have feathers (birds) and blind. • They need to be fed and kept warm.

PRECOCIAL YOUNG

ALTRICIAL YOUNG

Parental care

• Refers to looking after young ones through feeding, keeping them warm, protecting them from the predators. • Such animals give rise to few offspring.

RESOURCE

https://wordmint.com/public_puzzles/200551 https://worksheets.theteacherscorner.net/make-your-own/crossword/ https://teachingresources.co.za/product/grade-12-vertebrate-reproductive-strategies-powerpoint- caps/ https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_Introductory_ Biology_(CK-12)/10%3A_Animals/10.8%3A_Reproductive_Behavior_of_Animals

MODULE SUMMARY

Vertebrates have developed various reproductive strategies and the study of these strategies enable learners to explain why certain strategies ensure survival of the species in the environment they occur in. In order to understand this topic, learners must know the following concepts: internal and external fertilization, ovipary, ovovivipary, vivipary, precocial and altricial development, the amniotic egg and parental care.

REFERENCES

• DBE Exam guidelines for learners • GDE ATP • 2015-2019 NSC past papers

• 2014-2018 national diagnostic report on learner performance • Approved grade 12 national textbooks • ‘Mind the Gap’ • Internet • Gauteng grade 12 Life Sciences Revision booklet

Module 4 Reproduction in humans

INTRODUCTION

The main aim of human reproduction is to produce babies to continue the species. In human reproduction, two gametes (the sperm and ovum) fuse during conception to form a zygote that will eventually become a new baby. Puberty is the stage in the human life cycle when the sexual organs mature and prepare for reproduction.

The pituitary gland below the brain releases hormones that stimulate the testes and ovaries to release hormones that will start the production of sperm in the male and the maturation of ova (egg cells) in the female. In males, the hormone testosterone stimulates the testes to produce sperm. In females, the hormone oestrogen stimulates the ovaries to produce mature ova. Testosterone and oestrogen cause different secondary changes in the body. Females begin to menstruate, grow breasts and grow pubic and underarm hair, and may experience acne. Males grow hair on the pubic area, on the face, chest and underarms, develop a deep voice and may develop acne.

The male reproductive organs are: penis, sperm duct (vas deferens), testes, scrotum and urethra. Sperm is produced in the testes. The female reproductive organs are: vagina, cervix, uterus, oviducts (Fallopian tubes) and the ovaries. Ova are produced in the ovaries.

Stages in the reproductive cycle include: ovulation → copulation → fertilisation → embryo implants in uterus → results in pregnancy → gestation lasts 40 weeks → childbirth.

OVERVIEW

This module deals with human reproduction. The module starts with notes and important “tips” for learners. There is a detailed terminology list, notes on the following topics: structure of the male and female reproductive system; puberty; gametogenesis; menstrual cycle; fertilization and development of the zygote; implantation, gestation and the role of the placenta.

SPECIFIC OBJECTIVES

By the end of this session, participants will be able to:

• Teach the terminology associated with human reproduction • Classify questions on the different levels of Bloom’s taxonomy. • Answer questions on human reproduction.

CONTENT

You will study this module through the following units:

Unit 1: How do we teach terminology and define the concepts of human reproduction? Unit 2: Structure of the male and female reproductive system Unit 3: Puberty Unit 4: Gametogenesis Unit 5: Menstrual Cycle Unit 6: Fertilization and development of the zygote Unit 7: Implantation, gestation and the role of the placenta

IMPORTANT notes:

• Learners MUST understand the structure, identify and label structures of the male and female reproductive system. • Learners MUST be able to explain gametogenesis and draw the male and female gametes. • Learners MUST be able to explain the role of the various hormones in the menstrual cycle. • Learners MUST have a clear understanding of the terminology in order to study case studies related to the menstrual cycle. • Learners MUST be able to list the functions of the placenta and amniotic fluid and understand the differences between the two. • Learners MUST be able to identify the site of fertilization and development of the blastula until implantation • The main types of questions based on this topic are :

- Terminology

- Diagrams of the male and female reproductive system

- Tables or graphs to be interpreted on the menstrual cycle

- Description of fertilization and development of the blastula

How do we teach terminology and define the concepts of reproduction in humans

DEFINITIONS AND IMPORTANT TERMS AND CONCEPTS

Biological term Description

Acrosome The vesicle which contains enzymes found in the head of a sperm cell A fluid that protects the human embryo against injuries and large-scale Amniotic fluid temperature changes Blastocyst/blastula A hollow ball of cells formed from the zygote

Chorion The outermost membrane found around the embryo/foetus The introduction of the male sex organ into the female sex canal, followed Copulation by a discharge of semen. Endometrium The inner lining of the uterus where implantation of the embryo occurs

Fallopian tube Part of the female reproductive system where fertilisation occurs

Fertilization When the nucleus of the sperm cell fuses with the nucleus of the ovum Follicle stimulating The hormone responsible for the development of follicles in the ovary hormone/FSH The period between fertilization and birth when the foetus develops in the Gestation womb The attachment of the fertilized egg or blastocyst to the wall of the uterus Implantation at the start of pregnancy. The hormone responsible for ovulation and the formation of the corpus Luteinising hormone/LH luteum The hormone that causes the thickening of the endometrium and is Oestrogen produced by the Graafian follicle Oogenesis The production of female gametes through meiosis A hormone produced by the pituitary gland/hypophysis that stimulates Prolactin milk production in human females Puberty The stage in humans when sexual maturity is reached in males and females

Spermatogenesis The production of male gametes through meiosis A hormone that stimulates the maturation of sperm and stimulates Testosterone puberty in males Vas deferens The male reproductive tube that connects the testis with the urethra

Zygote The diploid cell formed by the process of fertilisation

Activity 4.1

AIM: To enable participants to create crossword puzzles, word search and word scramble on the internet in order to enforce terminology activities in class BACKGROUND: Terminology is key to performance in Life Sciences. Learners must be given amble opportunities to learn the terms associated with the content METHOD: complete the following terminology word scramble using the clues given .

Clues to unscramble the terms (in random order)

1. The production of male gametes through meiosis 2. The structure where mother’s blood and foetal blood do not mix 3. Membrane that surrounds and protects the developing foetus 4. The release of the immature ovum on day 14 5. Tearing away of the lining of the uterus 6. Hormone that stimulates milk production

7. The diploid cell formed by the process of fertilisation 8. A hormone found in females secreted by the Graafian follicle 9. Ball of cells that implants in the uterus 10. Lining of the uterus that is very vascular

Structure of the male and female reproductive system

HUMAN LIFE CYCLE

• Schematic diagram of the human life cycle to show the role of the meiosis, mitosis and fertilization

Activity 4.2

AIM: To enable participants to distinguish between concepts of the reproductive system Method: complete the following table:

Structure Female Male Sex organ

Copulatory organ

Gamete

STRUCTURE OF THE MALE REPRODUCTIVE SYSTEM

Consists of:

• A pair of testes situated in the scrotum. • The epididymis, vas deferens, ejaculatory duct and urethra • The seminal vesicles, prostate gland and Cowper’s glands. • The penis

• The testes are the male sex organs occurring in the scrotum which lies outside the abdominal cavity • The seminiferous tubules are found inside of each testis. • These tubules are lined with germinal epithelial cells which produce the spermatozoa by spermatogenesis. • Inside the seminiferous tubules there are specialized cells called Sertoli cells. • These cells are rich in glycogen which is thought to serve as nutrients for the spermatids as they develop into sperm or spermatozoa. • The epididymis is a coiled tube lying outside each testis within the scrotum. Leads off of the seminiferous tubule and stores sperm temporarily before sending it to the vas deferens. • The vas deferens Is also called the sperm duct it carries the spermatozoa from the epididymis through the abdomen into the ejaculatory duct • Ejaculatory ducts join the urethra just after it leaves the bladder. Contractions of the muscular walls of the ejaculatory duct force the semen through the urethra.

• The urethra is a tube which runs through the penis and opens at the tip of it. It is a common tube for urine and semen. • There are three accessory glands: • Seminal vesicles – produce seminal fluid to transport the sperm cells • Prostate gland – secretes a clear, slightly alkaline fluid that makes up 1/3 of the volume of semen • Cowper’s glands secrete fluid containing nutrients for the sperm • Secretions of the prostate and Cowper's glands nourish the sperm enabling them to swim and provide protection • The penis is the copulatory organ, made up of spongy tissue which fills with blood causing the penis to become erect before it is inserted into the female organ. • Responsible for transferring spermatozoa from the male to the female.

THE STRUCTURE OF THE FEMALE REPRODUCTIVE SYSTEM Consists of: • A pair of ovaries • Fallopian tube leading from each ovary • Uterus or womb • Vagina or birth canal • Vulva or external opening

• The ovaries are the female sex organs. • Found in the lower part of the abdominal cavity. • Held in place by ligaments. • Made up of a covering of germinal epithelium with a large number of follicles in it. • Germinal epithelium produces follicles. • Oogenesis takes place within follicles to produce ova. • Follicles secrete oestrogen and progesterone

• Fallopian tubes transport the ova from the ovaries to the uterus. • The upper parts of the fallopian tubes are expanded into ciliated funnels which partially enclose the two ovaries

• The Uterus is a pear shaped, hollow organ with muscular walls. • Endometrium lines the uterus and is richly supplied with blood vessels • Neck of uterus is called the cervix and extends into the vagina • Serves for attachment of the embryo if fertilization takes place. • The vagina is a cylindrical sheath like structure that leads from the cervix to the outside forming the opening called the vulva. • During copulation the penis is inserted into the vagina where spermatozoa are released.

Puberty

PUBERTY • This is a time of life when a person becomes sexually mature. • Physical changes occur between 10 and 14 in girls and 12 and 16 for boys. • It begins when the hypothalamus in the brain starts releasing gonadotropin-releasing hormone (GnRH).

IN MALES…

• starts when GnRH stimulates the anterior pituitary gland to secrete: – Follicle Stimulating Hormone (FSH) – which stimulates the testes to produce sperm,

– Luteinising hormone (LH) – which stimulates the testes to produce testosterone – Secondary sexual characteristics (caused by testosterone) • Rapid increase in height, size and strength of muscles • Development and functioning of the prostate gland, seminal vesicles and Cowper’s glands • Voice deepens • Hair grows in the pubic area, armpits and on the face • Testes and penis increase in size

IN FEMALES…

• starts when GnRH stimulates the anterior pituitary gland to secrete: − Follicle Stimulating Hormone (FSH) – stimulates a follicle in the ovary to develop and secrete oestrogen − Luteinising hormone (LH) – stimulates the development of the corpus luteum in the ovary to secrete progesterone (not responsible for secondary sexual characteristics) − Secondary sexual characteristics (caused by oestrogen) • Rapid increase in height and breast development • Hair growth in the pubic area and armpits • Increase in size of the vagina • Uterine and endometrial growth • Onset of menstruation • Increase in body fat

Gametogenesis

GAMETOGENESIS

SPERMATOGENESIS

• The germinal epithelium undergoes meiosis • Producing 4 haploid spermatids • Mature to form a spermatozoon • Each spermatozoon is made of a head, middle portion and a tail

• The head is mainly made up of the nucleus containing 22 autosomes and either an X or Y gonosome. • The middle piece is made up of numerous mitochondria to provide energy for locomotion. The mitochondria contain mitochondrial DNA. • The long tail enables the sperm to swim

OOGENESIS

• Refers to the process by which ova are produced from the germinal epithelium of the ovaries. • At puberty the germinal epithelial of the ovary starts to produce ova by meiosis. • One cell inside a follicle undergoes meiosis. • 4 haploid cells formed. • 3 cells break up; one cell matures into the ovum.

• Consists of a haploid nucleus, surrounded by cytoplasm. • The nucleus bears the genetic material from the mother while the cytoplasm serves as nutritive material to nourish the future zygote. • The ovum is enclosed in a vitelline membrane. • One ovum is produced and released every 28 days. It is produced by meiosis and therefore has 22 autosomes (single chromosomes) and an X gonosome.

The ovum in the fallopian tube

Activity 4.3 AIM: To enable participants to identify and label the structure of the reproductive system and gametes

Method: answer the questions DBE P1 NOV 2019

OVARIAN AND MENSTRUAL CYCLES

• Series of events occurring in the ovary and uterus • an ovum is matured and released by the ovary • the endometrium builds up in preparation for implantation • Over a 28-day period

OVARIAN CYCLE AND HORMONE CONTROL

Day Day Day 14 1 28 OVULATION FOLLICULAR PHASE LUTEAL PHASE

• Day 1: hypophysis secretes FSH • This stimulates the growth of the Graafian Follicle in the ovary • Day 7 – 14 • As levels of FSH increase in blood so the Follicle grows and matures • It fills with fluid causing the follicle to swell • Day 7 – 14 • The follicle secretes oestrogen • this prepares the endometrium for implantation • The endometrium becomes thick and vascular

• Day 12: the hypophysis stops secreting FSH and starts secreting Luteinizing Hormone (LH) • Day 14 : OVULATION • The Graafian follicle ruptures • Secondary oocyte is released • The Corpus Luteum (yellow body) develops from the Graafian follicle • Day 17 – 28: The Corpus Luteum secretes progesterone • This along with oestrogen this increases the thickness of the endometrium • if fertilization occurs then levels of oestrogen and progesterone stay high • if fertilization does not occur then: • Levels of LH and drop causing the Corpus Luteum to degenerate • Thus, levels of oestrogen and progesterone in the blood drop. • Day 28: This causes the endometrial lining of the uterus tears away • The cycle begins again

Activity 4.4 AIM: to enable participants to read with understanding and answer questions from a case study based on the ovarian and menstrual cycles BACKGROUND: Learners must be able to apply their knowledge to new scenarios. METHOD: read the information and answer the questions DBE/Nov 2019

2.4.1 The oestrogen levels between days 8 and 22 will remain low in the woman who takes contraceptive pills. Explain why this is the case. (4) 2.4.2 Ovulation took place on day 14 in the woman not taking contraceptive pills. Explain the evidence in the graph that supports this conclusion. (2) 2.4.3 Suggest ONE reason for including pills with no hormones in the contraceptive pill packet. (1) (7)

FERTILIZATION

• Spermatozoa deposited in the vagina move by spiral movements towards the ovum in the fallopian tubes • The head of one sperm cell penetrates the membranous barrier around the ovum • Enzymes from the acrosome hydrolyse these barriers • The spermatozoon loses its tail • The yolk membrane becomes impenetrable to other sperm • The pronuclei of the male and female fuse • Two sets of chromosomes lie on the equator • Fertilization occurs in the fallopian tubes forming a zygote • The zygote undergoes mitosis to form a ball of cells called a blastula • The blastula moves along the fallopian tube until it reaches the uterus

Implantation, gestation and the role of the placenta

IMPLANTATION • The blastula forms two sac-like structures • amnion • yolk sac • The outer most covering is called the chorion • The yolk sac shrinks • The amnion fills with fluid and fuses with the chorion after 2 months • Villi develop from the chorion • These become larger and more vascular • Called attachment villi • The region of the endometrium undergoes further changes and forms a placenta

THE PLACENTA

Development of the Placenta

• Large spaces or sinuses develop in the decidua or endometrium where attachment occurs • Attachment villi fit into theses spaces • where maternal blood bathes the villi • NB!! Maternal and foetal blood never mix • One vein and two arteries form the umbilical cord • Nutrients diffuse from maternal blood across the membranes into foetal blood Functions of the placenta

1. Nutrition • Nutrients including vitamins and minerals diffuse from the maternal blood to the foetus 2. Gaseous exchange • Oxygen and carbon dioxide are exchanged between maternal and foetal blood 3. Excretion • Nitrogenous wastes are carried away from the foetus by maternal blood 4. Protection • The placenta acts as a barrier or filter for certain harmful pathogens and chemicals • Maternal antibodies cross the placenta to the foetus • However, HIV and alcohol are able to cross this barrier 5. Endocrine function • After two months the placenta takes over the secretion of progesterone and oestrogen to maintain the endometrial lining • Secretes relaxin to relax joints and ligaments to assist delivery of the foetus

100

Amnion and amniotic fluid

• The amnion is a membranous structure in which the foetus develops • It is impenetrable and secretes fluid in which the foetus lives and moves

Functions of amniotic fluid • 1. Shock absorber – protects the foetus from mechanical injury • 2. Thermoregulatory – prevents extremes temperature changes • 3. Moisturising – prevents desiccation (drying out) of the foetus • 4. Environment – provides the medium in which the foetus moves, breathes and swallows

Amniocentesis • Test carried out at 12 weeks to diagnose any genetic disorders the foetus may have e.g. Down Syndrome • Amniotic fluid consists of 99% water as well as a mix of foetal cells, micro-organisms and waste products

Pregnancy or gestation • The period between fertilization and birth when the foetus develops in the womb

101

Activity 4.5 AIM: To enable participants to answer questions based on artificial selection. To enable participants to classify questions according to Bloom’s taxonomy. BACKGROUND: Teachers must be able to set questions on different levels of bloom’s taxonomy. METHOD: Classify the questions according to Blooms Taxonomy in the weighting grid provided below Answer the following questions based on human reproduction.

Limpopo DBE/September 2019

QUESTIONS 1.1.4 and 1.1.5 REFER TO THE FOLLOWING INVESTIGATION

In an investigation, a group of scientists collected data on how smoking influences the length of pregnancies. The normal average length of pregnancy is 42 weeks. The scientists collected the following data: • 1% of mothers who smoked heavily gave birth at 24 weeks compared to 0,36% of non- smoking mothers; • 1,2% of mothers who smoked heavily gave birth at 30 weeks compared to 0,46% of non- smoking mothers; • 1,8% of mothers who smoked heavily gave birth at 36 weeks compared to 0,9% of non- smoking mothers.

1.1.4 The average percentage difference, in early births between mothers who smoke heavily and non-smoking mothers is …

A. 0,76% B. 2,28% C. 4% D. 1,72%

1.1.5 The scientists measured the dependent variable by …

A. Dividing the smoking and non-smoking woman into two groups. B. Calculating the % woman giving birth. C. Compare the number of woman giving birth early and woman who gave birth at 42 weeks. D. Calculating the % smoking and non-smoking woman who gave birth early at 24, 30 and 36 weeks.

102

OED Common Exam September 2019 1.5 The diagram below represents two different human gametes.

1.5.1 Which ONE of the above gametes (A or B) consist of: (a) 22 autosomes and one X chromosome only (1) (b) 22 autosomes and one Y or one X chromosome (1) 1.5.2 Give the LETTER and NAME of the part that: (a) Releases enzymes to penetrate the ovum (2) (b) Contains many mitochondria to generate energy for the forward movement (2) 1.5.3 Name the: (a) Cell formed when G fuses with D (1) (b) Process by which the cell formed in QUESTION 1.5.3 (a) is formed (1) (c) Chromosome number of the cell formed in QUESTION 1.5.3 (a) (1) (9)

DBE/Nov 2019

2.5. Describe the development of a zygote until implantation occurs (4)

103

Weighting grid LIFE SCIENCES ANALYSIS GRID MID YEAR EXAM GRADE 12 2020 COGNITIVE LEVELS KNOWLEDGE STRANDS Life at Molecular, Diversity, Question Cellular and Tissue Change and

no A B C D Level Continuity

& &

analysing

Meiosis

knowledge knowledge

environment

Knowing Science Knowing

Endocrine System Endocrine

Applying Scientific Scientific Applying

Human Responses to to Responses Human

Human Reproduction Human

synthesizing scientific scientific synthesizing

Understanding Science Understanding Evaluating, Evaluating, Reproduction Vertebrate 1.1.4 1.1.5 1.5.1 (a) 1.5.1 (b) 1.5.2 (a) 1.5.2 (b) 1.5.3 (a) 1.5.3 (b) 1.5.3 (c) 2.5 sub total

RESOURCE

https://wordmint.com/public_puzzles/200551 https://worksheets.theteacherscorner.net/make-your-own/crossword/ https://www.siyavula.com/read/science/grade-9/human-reproduction/03-human- reproduction?id=toc-id-18 https://www.youtube.com/watch?v=2j0Y3R_Upgc https://www.youtube.com/watch?v=_5OvgQW6FG4

104

MODULE SUMMARY

The structures of the male and female reproductive system must be studies with the aid of diagrams. It is important to remember that learners need to have a copy of the male reproductive system as a side view and a front view. The diagram of the ovum is not typical of all textbooks and therefor the teacher must ensure that learners have a labelled copy.

Graphing skills (reading and constructing) are very important in this topic as the different cycles associated with reproduction are mainly represented by graphs.

REFERENCES

• DBE Exam guidelines for learners • GDE ATP • 2015-2018 NSC past papers • 2014-2018 national diagnostic report on learner performance • Approved grade 12 national textbooks • ‘Mind the Gap’ • Internet • Gauteng grade 12 Life Sciences Revision booklet

105