springschool_lifesci1+2

Life Sciences

Paper 1 and 2

Spring School 2011

3rd – 7th October

Learner’s Guide

Life Sciences Paper 1and 2 Exam Revision Learner’s Guide Spring School October 2011

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Brought to you by Page 1

Contents Introduction 2

Getting the most from Spring School 2

Programme outline 3

Broadcast Schedules 4

Paper 1 Topic 1: DNA, RNA and Meiosis 5

Paper 1 Topic 2: Evolution 12

Paper 1 Topic 3: Genetics 19

Solutions to Paper 1 Topic 1: DNA, RNA and Meiosis 23

Solutions to Paper 2 Topic 2: Evolution 27

Solutions to Paper 1 Topic 3: Genetics 35

Paper 2 Topic 1: Life Processes 39

Paper 2 Topic 2: Environmental Studies 48

Paper 2 Topic 3: Reproduction 61

Solutions to Paper 2 Topic 1: Life processes 67

Solutions to Paper 2 Topic 2: Environmental Studies 72

Solutions to Paper 2 Topic 3: Reproduction 78


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Introduction Have you heard about Mindset? Mindset Network, a South African non-profit organisation, was founded in 2002. We develop and distribute quality and contextually relevant educational resources for use in the schooling, health and vocational sectors. We distribute our materials through various technology platforms like TV broadcasts, the Internet (www.mindset.co.za/learn) and on DVDs. The materials are made available in video, print and in computer-based multimedia formats. At Mindset we are committed to innovation. In the last two years, we successfully ran a series of broadcast events leading up to and in support of the NSC examinations Now we are proud to announce our 2011 edition of Matric Exam Revision, which began with our Winter School in July. We’ve expanded the broadcast to support you in seven subjects - Mathematics, Physical Sciences, Life Sciences, Mathematical Literacy, English 1st Additional Language, Accounting and Geography. During our Spring School, you will get exam overviews, study tips on each of the topics we cover, detailed solutions to selected questions from previous examination papers, short question and answer sessions so you can check you are on track and live phone in programmes so you can work through more exam questions with an experienced teacher. Getting the most from Spring School Before you watch the broadcast of a topic, read through the questions for the topic and try to answer them without looking up the solutions. If you get stuck and can’t complete the answer don’t panic. Make a note of any questions you have. When watching the Topic session, compare the approach you took to what the teacher does. Don’t just copy the answers down but take note of the method used. Make sure you keep this booklet for after Spring School. You can re-do the exam questions you did not get totally correct and mark your own work by looking up the solutions at the back of the booklet. Remember that exam preparation also requires motivation and discipline, so try to stay positive, even when the work appears to be difficult. Every little bit of studying, revision and exam practice will pay off. You may benefit from working with a friend or a small study group, as long as everyone is as committed as you are. Mindset believes that the 2011 Spring School programme will help you achieve the results you want. If you find Spring School a useful way to revise and prepare for your exams, remember that we will be running Exam School from 15th October to 22nd November as well where we will be repeating material from Spring School with additional live shows. See the full schedule below.

http://www.mindset.co.za/learn


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Programme Outline The Mindset Winter School is designed to focus on two subjects each day. For each subject you will find the following sessions:

Examination Overview

This is a 15 minute session that gives details of what you can expect in each examination paper. Practical guidelines are also given on how to prepare for the day of the exam.

Topics Tips

In this session you will be given a 15 minutes summary of the key ideas you need to know, common errors and study hints to help you prepare for your exams.

Topic Session

An expert teacher will work through specially selected questions from previous exam papers.

Live Phone-in

This is your chance to ask your own questions. So submit your question to the Help Desk and we might call you back to help you live on TV. All questions you submit will be answered within 48 hours as normal. The Help Desk is available through the following channels.

Web: www.learnxtra.co.za

MXit: learnxtrahelpdesk

Facebook: www.facebook.com/learnxtra

Email: [email protected]

Phone: 086 105 8262

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http://www.facebook.com/learnxtra

mailto:[email protected]


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Broadcast Schedules Spring School

Monday 3

rd

October Tuesday 4

th

October Wednesday 5

th

October Thursday 6

th

October Friday 7

th

October

09h30 Maths Paper 1: Calculus

English FAL: Paper 2

Physical Sciences Paper 1: Waves, Sound and Light

Maths Paper 2: Trigonometry – Graphs and Solving 3D Problems

Physical Sciences Paper 2: Electrochemistry

13h00 Lunch

13h30 Maths Literacy: Shape and Space

Accounting: Manufacturing Accounts

Life Sciences Paper 1: Evolution

Geography: Climatology

Life Sciences Paper 2: Environmental Studies

17h00 Maths Paper 1: Linear Programming


Physical Sciences Paper 1: Mechanics

Maths Paper 2: Trigonometry – Equations and Identities

Physical Sciences Paper 2: Organic Chemistry

19h00 Maths Literacy: Data Handling

Accounting: Cash Flow and Interpreting Statements

Life Sciences Paper 1: DNA & RNA

Geography: Geomorphology

Life Sciences Paper 2: Life Processes

21h00 Maths Paper 1: Functions


Physical Sciences Paper 1: Electricity and Magnetism

Maths Paper 2: Co-ordinate Geometry and Transformations

Physical Sciences Paper 2: Rates and Chemical Equilibrium

23h00 Maths Literacy: Financial Maths

Accounting: Financial Statements

Life Sciences Paper 1: Genetics

Geography: Mapwork Life Sciences Paper 2: Reproduction

01h00 Broadcast Ends

Exam School

Saturday 15th October: Prelim Review – Mathematics, Physical Sciences, Life Sciences, Maths Literacy

Wednesday 19th October: Maths Literacy Paper 2

Thursday 20th October: Mathematics Paper 2

Friday 21st October: English FAL

Saturday 22nd October: Prelim Review - Mathematics, Physical Sciences, Life Sciences, Maths Literacy

Sunday 23rd October: Accounting

Monday 24th October: Accounting

Tuesday 25th October: Mathematics Paper 1

Wednesday 26th October: Maths Literacy Paper 1

Thursday 27th October: Mathematics Paper 1

Saturday 29th October: Mathematics Paper 2

Tuesday 8th November: Physical Sciences Paper 1

Wednesday 9th November: English FAL

Thursday 10th November: Physical Sciences Paper 1

Saturday 12th November: Physical Sciences Paper 2

Sunday 13th November: Physical Sciences Paper 2

Monday 14th November: English FAL

Wednesday 16th November: Life Sciences Paper 1

Thursday 17th November: Life Sciences Paper 1

Saturday 19th November: Life Sciences Paper 2

Sunday 19th November: Life Sciences Paper 2

Monday 21st November: Geography

Tuesday 22nd November: Geography


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Paper 1 Topic 1: DNA, RNA and Meiosis Question 1 (DNA) The following is a representation of a portion of a DNA molecule. Study the diagram and answer the questions that follow.

1.1. Give TWO functions of DNA (2) 1.2. Provide labels for parts numbered 1 to 4 (4) 1.3. Exactly where in the cell would you expect to find this structure? (1) 1.4. Name the monomers of this molecule. (1) 1.5. Describe the type of bond found between G and 3. State the significance of

this type of bond. (3) 1.6. In terms of the structure represented in the diagram , explain what

a gene is. (2) [13]

.

1

2

4

C

G 3

A


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Question 2 (DNA) Adapted from September , 2010, Paper 1, Question 2.1. Very complex procedures were used by scientists to determine the finer details of the physical and chemical nature as well as the composition of DNA. Scientists used chemical analysis to provide evidence of the relationships among the nitrogenous bases of DNA. Study the information in the table and answer the questions that follow.

Question 2

Adapted from September , 2010, Paper 1, Question 2.1.

Samples

PERCENTAGE OF NITROGENOUS BASES

IN DNA SAMPLE

Adenine

(A)

Guanine

(G)

Cytosine

(C)

Thymine

(T)

Human

liver cells30.3 19.5 19.9 30.3

Yeast 31.7 (a) (b) 31.7

2.1 Compare the amounts of Nitrogenous bases in the sample of human liver

cells. (2) 2.2 Calculate the percentage of Guanine in the DNA sample of yeast. Show all

workings. (3) 2.3 The sequence of bases on a portion of one strand (template) of DNA is

ACGT. Draw a labelled diagram of the portion of the complete DNA molecule. (5)

[10]


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Question 3 (MEIOSIS) Adapted from September, 2010, Paper 1, Question 1.6. The diagram below represents stages in the process of meiosis. They are , however, not in the correct sequence. Study the diagram and answer the questions that follow.

3.1 Identify the stages B and C. (2)

3.2 Provide labels for 1 , 2 and 3. (3)

3.3 Name TWO places in the human body where meiosis would occur. (2)

[7]


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Question 4 (MEIOSIS) Adapted from November, 2010, Paper 1, Question 2.1. The diagram below represents an animal cell in a phase of meiosis

4.1 Label C and D. (2) 4.2 (a) Identify the phase represented in the diagram above. (1)

(b) Give a reason for your answer to QUESTION 4.2(a). (2) 4.3 Name the process which resulted in parts A and B being different from each

other. (1) 4.4 Describe how the process referred to in QUESTION 4.3 occurs. (3) 4.5 State the importance of the process named in QUESTION 4.3. (1) 4.6 (a) How many cells will be formed at the end of the first division of the cell

drawn in the diagram above? (1) (b) How many chromosomes will each daughter cell have when the cell, drawn in the diagram above, has completed meiosis? (1)

[12] Question 5 (DNA-RECOMBINANT TECHNOLOGY)) Adapted from September, 2010, Paper 1, Question 1.5. Read the passage below and then answer the questions based on it . “In 1973 U.S. biochemists Herbert Boyer and Stanley Cohen made the first recombinant DNA. They cut open plasmids (DNA rings) of the bacterium Escherichia coli using a restriction enzyme. Then they added a section of DNA from another plasmid and used ligase to join the two together to re-form the ring of DNA “ This technology was later used and applied to the production of human insulin using bacteria. (The insulin can then be used in the treatment of Diabetes mellitus). A diagrammatic representation of this process is shown below


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5.1 The steps involved in this process are listed below . The order is, however,

not correct. Place the steps in their correct sequence by writing down only the letters as they occur.

A The bacterial plasmid ring is cut. B The plasmid is inserted into an E.coli bacterium C Insulin is produced by the bacterium. D The DNA with the insulin gene is added, and the plasmid ring is joined up again. E Human DNA containing the insulin gene is copied. F Millions of bacteria are produced by repeated divisions

(6) 5.2 State how the “re-joining” of the plasmid is ensured. (1) 5.3 What is meant by a transgenic bacterium? (1) 5.4 In the past, the pancreas of certain animals was used to extract insulin. State

ONE disadvantage of using animal pancreas to treat Diabetes. (2) [10]


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Question 6 (DNA ANALYSIS) Adapted from September, 2009,(Kwa-Zulu Natal) Paper 1, Question 1.4. A company claimed that the burger patties that they produced were 100% beef . A rival company suspected that the first company was actually putting soya protein into their burger patties .This allowed them to sell patties at a cheaper price. The second company was losing a lot of money, so they sent the cheap patties to be analysed in a lab. The DNA profiles /fingerprints for the cheap patties, pure beef and soya protein are shown below. Study them and then answer the questions that follow

6.1 Explain what DNA profiling/fingerprinting is. (2) 6.2 Was the company truthful about the claim it was making? Explain your answer

using evidence from the DNA profiles/fingerprints. (3) 6.3 List THREE other ways in which the technology of DNA profiling /

fingerprinting is useful. (3) 6.4 List TWO other ways in which un-ethical people could abuse the use of DNA

profiling / fingerprinting technology. (2) [10]


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Question 7 (DNA /RNA) Adapted from November , 2010, Paper 1, Original Question Number 2.4 Analysis of DNA samples from a patient with an illness showed that there were two different types of DNA present .One was double stranded human DNA and the other was single stranded virus DNA. The two types of DNA were isolated and put into separate test tubes .The analyses of the nitrogenous base composition of each test tube is shown in the table below.

7.1 Which test tube (1 or 2) contains virus DNA? (1) 7.2 Explain your answer to question .7.1. (2) 7.3 Tabulate THREE structural differences between DNA and RNA. (7)

[10]

Nitrogenous Base Composition

Adenine Cytosine Guanine Thymine

Test tube 1 22.1 27.9 27.9 22.1

Test tube 2 31.1 31.3 18.7 18.9


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Paper 1 Topic 2: Evolution Question 1 Adapted from Nov, 2010, P2, 3.2 Lamarck based his theory of evolution on two principles, ideas or “laws”.

1.1 Name and describe TWO principles that Lamarck used to explain how evolution took place. (6)

1.2 Explain ONE reason why Lamarck’s theory is NOT accepted. (2) Question 2 Adapted from Nov, 2010, P2, 3.1 Read the following passage and answer the questions that follow. Thousands of wildebeest were migrating across the great plains of the Serengeti in Africa. Some of them were large, some small, some strong and some weak. Lions followed the wildebeest, catching and eating the slowest ones. Water was scarce and only the strongest were brave enough to stop to drink from the waterholes.

2.1 Identify ONE phrase in the passage which describes variation among wildebeest.

2.2 Explain how Darwin’s idea of evolution by natural selection can be applied to this passage.

Question 3 Adapted from March, 2010, P2, 2.2 Study the diagram of a duck's foot below

3.1 Ancestors of ducks did not have webbed feet. In terms of natural selection,

explain how the webbed feet could have evolved. (7) Question 4 Adapted from March 2011, P2, 3 Darwin noticed different species of tortoises on the Galapagos Islands. Two of these tortoises, which are drawn to scale, are show below.


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4.1 Tabulate TWO visible difference between the two species of tortoises. (5) 4.2 Suggest what tortoise 2 may eat that tortoise will not be able to eat. (1) 4.3 The two species of tortoises shown above live on different islands. Darwin

suggested that they might have evolved from a common ancestor. Explain how this could have occurred. (6)

4.4 Explain how Lamarck would have explained the long necks of the tortoises. (5)

Question 5 Adapted from Nov, 2010, P2, 3.4 Study the diagrams below showing a process of evolution. DIAGRAMS 1, 2 and 3 show the sequence of events that occurred in rabbit populations over many thousands of years.


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5.1 Name the evolutionary process represented by the sequence of events shown in DIAGRAMS 1, 2 and 3 above. (1)

5.2 Describe the process stated in QUESTION 5.1 using the diagrams above. (5) Question 6 Adapted from Mar, 2010, P2, 3.2 Study the following diagrams which show different stages (1 to 4) of a process in evolution.

6.1 Name the evolutionary process that resulted from the continental drift shown. (1)

6.2 Describe how the original of species A to become two species as indicated in the diagrams above. (5)

Question 7 Adapted from Exemplar, 2011, P1,Q4 The information and question below are based on natural selection. Antibiotics are used to kill bacteria that cause diseases. In 1972, there was an epidemic of typhoid in Mexico. Normally, an antibiotic called chloramphenicol cured it. This time the antibiotic did not work and more than 14 000 people died. Eventually, doctors found an antibiotic that did work.

7.1 Using your understanding of natural selection, explain why chloramphenicol did not control the epidemic mentioned above. (5)


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Question 8 Adapted from Exemplar, 2011, P1, 4.2 Study the information below on an investigation based on artificial selection and answer the questions that follow. In 1965, an investigation was started to find out if artificial selection could increase the milk yield of cows. In one set of cows, artificial selection for high milk yield was carried out in each generation. This set of cows was called the SELECTED LINE. In the other set of cows, there was no artificial selection. This set was called the CONTROL LINE. Both sets of cows were kept under the same conditions. The average milk yield from both sets of cows that were born in each year from 1965 to 1990 was recorded. The results are shown in the table below. YEAR OF COW’S BIRTH 1965 1970 1975 1980 1985 1990

Selected line: average milk yield (litre per kg)

7,2 8,2 8,8 10,0 9,7 11,0

Control line: average milk yield (litre per kg)

7,2 7,1 6,0 6,8 6,6 5,8

8.1 Plot line graphs, on the same set of axes, using the information in the table

above. (12) 8.2 Calculate the change in average milk yield (litre per kg) between 1965

and 1990 for the selected line. Show your workings. (3) Question 9 Adapted from March, 2010, P2, 1.4 The diagram below shows a phylogenetic tree based on DNA similarities. The percentage next to each branch shows the amount of difference in the genome (DNA nucleotide sequence) of the two relevant groups.


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9.1 From the diagram, determine how long ago the chimpanzees split from the line to humans. (2)

9.2 Which organism is most closely related to humans? (1) 9.3 Calculate the DNA similarity between the genome of the chimpanzee and the

human. (2) Question 10 Adapted from March, 2011, P2, 1.6 Differentiate between:

10.1 Homologous and analogous structures (3) 10.2 Inbreeding and outbreeding (3) 10.3 Study the basic plans of the forelimbs of two different vertebrates

shown below.

10 3.1 Are the above forelimbs homologous or analogous structures? (1) 10.3.2 Explain your answer to QUESTION 10.1 (2) 10.3.3 Using the labels on the forelimb of a human as a guide, give the names

of the letters A and B. (2) 10.3.4 State TWO ways in which the forelimb of the bat is adapted for flying.

(2)


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Question 11 Adapted from March, 2011, P2, 4.2 Study the image.

11.1 Identify each of the organisms that are represented by A and B (2) 11.2 Tabulate FOUR observable differences between the skulls of

organisms A and B. (9) 11.3 Which organism is bipedal for most of its adult life? (1) 11.4 Explain TWO possible advantages of bipedalism to the organism

referred to in QUESTION 11.3. (4) 11.5 Name any TWO similarities between organisms A and B. (2)

Question 12 Adapted from Exemplar, 2011, P1, 3.1 Diagrams A and B below illustrate the skulls of Homo sapiens and Homo erectus. The diagrams are drawn to scale.


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12.1 Which of the diagrams (A or B) represents the following: a. Homo sapiens (1) b. Homo erectus (1)

12.2 Tabulate TWO visible differences between the skulls in diagrams A and B that represent changes in the structure that characterises human evolution. (5)

12.3 Describe the significance of Homo erectus to the 'out of Africa' hypothesis. (3)

Question 13 Adapted from Nov, 2010, P2, 3.3 Study the diagrams below of the upper jaw, skull and the foot of two organisms A and B. The diagrams are NOT drawn to scale.

13.1 With regard to the drawings above: (a) Tabulate TWO visible differences between the upper jaws of organisms A and B. (5) (b) Name ONE visible difference between the feet of organisms A and B. (2)

13.2 Which organism (A or B) is more likely to be bipedal? (1) 13.3 Give a reason for your answer to Question 1 (2)


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Paper 1 Topic 3: Genetics Question 1 Adapted from March, 2010, P1, question 1.5 Study the family tree below which shows inheritance of the type of little finger over four generations of a family.

1.1 How many members of the family have straight little fingers? (1) 1.2 Is person F homozygous or heterozygous for the type of little finger? (1) 1.3 Which type of little finger is controlled by a dominant gene? (1) 1.4 Explain your answer to QUESTION 1.3. (3) 1.5 In the fourth generation of the family, what proportion will be female with 1.6 a straight little finger? (2) 1.7 Persons F and G are twins. Were they produced from a single fertilised 1.8 egg cell? (1) 1.9 Give TWO reasons based on the phenotype to support your answer

to QUESTION 1.6. (2)

Question 1

KEY:

- Male with straight little finger - Female with straight little finger

- Male with bent little finger - Female with bent little finger

Family tree showing inheritance of type of little finger


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Question 2 Adapted from November, 2010, P1, 4.1 Study the karyotype of a human below and answer the questions based on it.

2.1 Is this karyotype that of a male or a female? (1) 2.2 Give a reason for your answer to QUESTION 2.1. (1) 2.3 Name the genetic disorder that the individual with this karyotype has. (1) 2.4 Give a reason for your answer to QUESTION 2.3. (2)

Question 3 Adapted from November, 2010, P1, 1.4 The diagram below shows the offspring of crosses between a pure-bred black coat bull and a pure-bred white coat cow. The coat colours of the offspring of the first and second generations are also shown. Coat colour is controlled by two alleles, one for black and one for white coat colour.

Question 2

Karyotype of a person with a genetic disorder


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3.1 Use the letters B and b and state which gene is responsible for the following (a) Black coat colour (1) (b) White coat colour (1)

3.2 Which animal(s) (1 to 8) in the diagram must be homozygous for coat colour? (3)

Question 4 Adapted from March, 2010, P1, 3.1. In rabbits the dominant allele (B) produces black fur and the recessive allele (b) produces white fur. Study the table below showing the genotypes of four rabbits.

Rabbit 1 2 3 4

Genotype BB Bb Bb bb

4.1 What are the phenotypes for rabbits 2 and 4 respectively? (2) 4.2 State the genotypic ratio that is shown in the table above (1) 4.3 If rabbits 1 and 4 were mated together and had 12 offspring, how many of

these would you expect to be black? (1) 4.4 Rabbit 2 was allowed to breed with rabbit 3. Use a genetic cross to show the

possible phenotypes and genotypes of the F1 generation for fur colour. (6) Question 5 Adapted from March, 2011, P1, 4.2 The table below shows the percentage frequency of human blood groups in the populations of two different cities in South Africa.

Human blood groups

% frequency in population

City 1 City 2

A 25 45

B 20 10

AB 10 5

O 45 40

5.1 Which blood group has:

(a)The highest frequency in City 1 (1) (b)The lowest frequency in City 2 (1)

5.2 Plot the data in the table as bar graphs on the same system of axes. (10 Question 6 Adapted from November, 2010, P1, 4.3 The blood bank wants to carry out an investigation to determine the distribution of blood groups of 1 200 learners in a high school. They decide to use a sample to do their investigation in order to save costs and time. They also want to get a reliable result.


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6.1 State any FOUR planning steps that the blood bank should put in place to do this investigation, before they draw blood from the learners, using a syringe. (4)

6.2 State THREE precautions that the blood bank should take when drawing blood from the learners. (3)

Question 7 Adapted from March, 2010, P1, 3.3 Read the passage below and answer the questions that follow.

Vaccine-producing bananas Vaccinations protect people all over the world from diseases. Scientists are working on producing a genetically modified banana that will act as a vaccine against hepatitis B, a liver disease that affects more than 2 billion people worldwide. In future, many vaccines and other medicines may be given to people and other animals in easy-to-eat fruit and vegetables.

7.1 State THREE possible advantages of using bananas as a vaccine against diseases. (3)

7.2 Give THREE reasons why people might be against the use of genetically modified bananas. (3)

Question 8 Adapted from November, 2010, P1, 4.4 Describe what stem cells are, and give TWO sources from which human stem cells may be harvested. Also explain TWO arguments, with reasons, for the use of stem cells and TWO arguments, with reasons, against the use of stem cells in humans. (12) Synthesis: (3) Note: No marks will be awarded for answers in the form of flow charts or diagrams


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Solutions to Paper 1 Topic 1: DNA, RNA and Meiosis Question 1 (DNA) 1.1. DNA controls the functioning of the cell DNA controls protein synthesis and thereby the formation of proteins and

hormones. Stores hereditary information and transmits this information from one

generation to the next (mark first two) (2) 1.2.

1- Deoxyribose sugar/Sugar 2- Phosphate 3- Cytosine 4- Thymine (4)

1.3. In the nucleus / mitochondria (1) 1.4. Nucleotides (1) 1.5. A Weak Hydrogen bond. During the process of replication , these bonds break easily, so that each strand can act as a template for a new DNA Molecule. (3) 1.6. A gene is a sequence of nucleotides on a DNA molecule (2)

[13] Question 2 (DNA) 2.1. Adenine and Thymine are the same (30.3%) and Guanine and Cytosine are almost the same (19.5 and 19.9%). (2) 2.2. A + T = 31.7 + 31.7 = 63.4%

100 – 63.4 = 36.6% Guanine = 36.6 ÷ 2 = 18.3% (3)


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2.3

Any (5)

[10] Question 3 (MEIOSIS) 3.1. B- Anaphase 1

C- Prophase 1

[Do not credit if only anaphase /prophase is given] (2)

3.2 1- Chiasma/Chiasmata

2- Centromere

3- Chromosome (3)

3.3. Testes and Ovaries Mark first 2 (2)

[7]

Mark allocation:

Heading =

Correct complement base pairs: o 2 complementary base pairs correct o 4 complementary base pairs correct

Correctness of diagram: o Hydrogen bond o correct sugar phosphate sequence o 2 DNA strands/chains/double helix


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Question 4 (MEIOSIS) 4.1. C- Spindle/ Spindle Fibre/ Spindle thread

D- Homologous pair / Bivalent /Tetrad/ Homologues (2) 4.2. a) Metaphase 1 (1)

b) Chromosomes are lined up at the equator in homologous pairs. (2) 4.3. Crossing over (1) 4.4. Homologous chromosomes pair up during prophase 1 of meiosis. The

chromatids facing each other with cross at points called chiasmata. An exchange of genetic material will occur between facing chromatids. (3)

4.5. It promotes genetic variation in the gametes (1) 4.6. a) 2

b) 2 (2) [12]

Question 5 (DNA RECOMBINANT TECHNOLOGY) 5.1. E A D B F C or A E D B F C (6) 5.2. A ligase enzyme is used to bond the two sticky ends together. (1) 5.3. A bacterium that has had its genetic make-up/gene sequence/DNA changed. (1) 5.4. Extraction from the pancreas is a time consuming process It is a very

costly procedure. People may be opposed to using animal products for religious / cultural / ethical reasons. Some individuals may have an allergic reaction to the animal product.

Mark first one (1x2) (2)

[10]

Question 6

6.1. Since no two people (except identical twins) have the same DNA sequence ,it is possible to use the DNA sequence to identify an individual. (2) 6.2. No. The cheap patties actually match exactly with the Soya and not at all with the beef (3) 6.3. Identification of a crime suspect Location of missing family members Paternity testing Identification of corpses (Mark first 3) (3)

6.4. Unethical individuals could “frame” other individuals by placing samples of

their DNA at the scene of a crime. They could swap laboratory samples used in forensics tests or paternity

tests (2) [10]


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Question 7 7.1. Test tube 2 (1) 7.2. Percentage of A does not equal T and percentage of C does not equal G in

test tube 2 , therefore it is evident that no base-pairing has occurred

OR

The percentages of A is equal to T and C is equal to G in test tube 1, therefore base pairing has occurred. Therefore test tube 2 contains the single stranded DNA molecule. (2)

7.3.

DNA RNA

1.Double stranded molecule/paired bases

1. Single stranded molecule /unpaired bases

2. Contains Deoxyribose sugar 2. Contains Ribose sugar

3. Contains nitrogenous base Thymine 3. Contains the Nitrogenous base Uracil

3. A is proportional to T ;and G is proportional to C.

4. Different relative numbers of A,T,G & C

5. A Longer molecule 5. A Shorter molecule

6. Helix /Helical in shape 6. Straight /non-helical structure

(Any 3x2) + 1 (Table) [10]


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Solutions to Paper 2 Topic 2: Evolution Question 1 Early Theories 1.1 *Principle of use and disuse/adaptation to the environment * compulsory mark - Structures of individuals in a population that are used more frequently became better/adapted - Structures of individuals in a population that are used less Frequently becomes smaller/disappear max *Principle of inheritance of acquired characteristics * compulsory mark - Acquired characteristics developed by the organism in its lifetime are passed on to its offspring (6) 1.2 Acquired characteristics are not inherited/do not cause any change to the DNA of an organism's gametes (sperms or ova) OR Organisms did not evolve because they wanted to evolve/ Lamarck’s theory is deterministic (2) Question 2 Early theories 2.1 “some large, some small” / “some strong and some weak” (1) 2.2 - Variation in the wildebeest population* (1) slow and weak, some large and strong were eaten by the lions survive and do not pass on and pass on their their characteristics to favourable characteristics to their offspring max 3 (3) - If this process continues from generation to generation the characteristic of the population will change* (1) * compulsory marks Question 3 Natural Selection 2.1 - There was variationwith regard to the feet within the ancestral duck populations - Some ancestral ducks had skin attached between the toes - As food became scarce/environment changed - Competition for food increased - Those ducks which had skin attached between their toes/ desired characteristic could swim better - To secure food and survived - Those ducks that did not have skin attached between their toes were unable to swim well- Did not secure food and died - Through natural selection entire populations of ducks with webbed feet evolved any (7)


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Question 4 Speciation 4.1

4.2 Tall plants/shrubs/small trees 4.3 - On each island there was variation (long and short) in the population of

tortoises lived under different environmental conditions different sources of food - After a period of time each group of tortoises underwent natural selection independently - On each island only those tortoises with the characteristics (long or short neck) favourable for its own conditions survived - Continued natural selection resulted in each island having tortoises that are very different from each other/ they differed genotypically and phenotypically - Reproductive isolating mechanisms prevented them from interbreeding even if they are allowed to mix i.e. each is a separate/new species any (6)

4.4 Lamarck would have explained the long necks of the tortoises as follows: All tortoises had short necks They needed to reach the taller trees and shrubs They thus stretched their necks repeatedly Their necks became longer - Law of Use They passed this acquired characteristic to their offspring Therefore all tortoises have long necks any (5) Question 5 Speciation 5.1 Speciation (1) 5.2 - In diagram 1 the rabbits were able to interbreed/genes can flow freely in

the population - In diagram 2 the two populations were separated by the river/geographic barrier

- The two populations cannot interbreed/no gene flow - Within each of the two separated populations there was variation

- Each group underwent natural selectionindependently as a result of varying environmental conditions


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- Each group becomes genotypically and phenotypicallydifferent - In diagram 3 the geographic separation no longer exist

- but the two populations do not interbreed/no gene flow even though they can mix

- because of the presence of reproductive isolating mechanism - They are now 2 different species any (5) Question 6 Speciation 6.1 Speciation (1) 6.2 The population of species A has split up into two The sea forms a physical

barrier and each group adapts to the new environmental factors Each group undergoes natural selection independently and develops separately Each group may become genotypically and phenotypically different Might prevent them from interbreedingwhen they come into contact again/become reproductively isolated leading to the formation of a new species (5)

Question 7 Present times 7.1 - There is a large degree of variation in the bacteria population

- When chloramphenicol was first used, it killed off a large number of bacteria - But some bacteria were resistant to chloramphenicol and survived - Those that survived were able to reproduce - Increasing the population of resistant bacteria - Continued use of chloramphenicol had little effect on the resistant bacteria - Hence the disease reappeared max

(5)


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Question 8 Artificial Selection 8.1

NOTE: If the wrong type of graph is drawn: - Marks will be lost for 'correct type of graph' If graphs are not drawn on the same system of axes: - Mark the first graph only using the given criteria Rubric for the mark allocation of the graph

Correct type of graph 1

Caption for graph 1

Correct label for X-axis 1

Graphs labelled/key provided for 2 graphs

1

Correct label for Y-axis 1

Appropriate scale for X-axis 1

Appropriate scale for Y-axis 1

Plotting 1 – 1 to 2 points plotted correctly

2 – 3 to 4 points plotted correctly 3 – 5 to 7 points plotted correctly 4 – 8 to 10 points plotted correctly 5 – 11 to 12 points plotted correctly

(12) 8.2 11, 0 – 7,2 = 3,8 litres/kg (3)

Comparison of the average milk yield in two sets of cows from

1965 to 1990

0

2

4

6

8

10

12

1965 1970 1975 1980 1985 1990

Year of Cow's birth

Av

era

ge

milk

yie

ld in

litr

es

/kg

Selected Control


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Question 9 Evidence – Biochemistry 9.1 5 mya (2) 9.2 Chimpanzee (1) 9.3 98,6% (2) Question 10 Evidence & Terminology 10.1 Similar structures

Homologous – that evolved from a common ancestor Analogous – that evolved from different ancestors (3)

10.2 Reproduction between organisms

Inbreeding – that are closely related Outbreeding – are not closely related (3)

10.3.1 Homologous (1) 10.3.2 Are similar in structure (slightly different function) suggesting a

similar/common origin/ancestor max (2) 10.3.3 A - Humerus B - Metacarpals/phalanges /carpals (2) 10.3.4 - There is a wing/web of skin between the metacarpals /skin - Forelimb and metacarpals are thin /light - Forelimb and metacarpals are long - Has a large surface area (Mark first TWO only) (2) Question 11 Human evolution 11.1 A – Gorilla B – Modern human (2) 11.2

11.3 B (1)


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11.4 - Allows total awareness of the environment in sensing danger/looking for food - Enables hands to be free to use implements/carry objects or offspring/throw/protect - Exposes a large surface area for thermo-regulation/lose body heat to surroundings in hot conditions/reduce overheating therefore reduce need for water

- Display of male/female sex organs as part of courtship behaviour (any 2 x 2) 11.5 - Capable of upright posture - Long upper arms - Freely rotating arms - Elbow joints allowing rotation of forearm - Rotate hands at least 180º - Flat nails instead of claws/bare finger tips - Opposable thumbs/which work in opposite direction to their fingers - Large brains/cranium compared to their body mass - Eyes in front/binocular vision/stereoscopic vision - Eyes with cones/colour vision - Sexual dimorphism/distinct differences between male and female - Olfactory brain centres reduced/reduced sense of smell

- Parts of the brain that process information from the hands and eyes are enlarged

- Two mammary glands only (Mark first TWO only) (2) Question 12 Human evolution 12.1 (a) B (1) (b) A (1) 12.2

Diagram A Diagram B

1 Brow ridges more pronounced 1 Brow ridges less pronounced

2 Smaller cranium/brain 2 Larger cranium/brain

3 Jaw protrudes (prognathous) 4 Not prognathous

4 No obvious chin 5 Pronounced chin

5 Elongated cranium 3 Shorter cranium

6 Zygomatic arch well developed 6 Zygomatic arch less developed

1 mark for table + (2 x 2) (5) 12.3 -H.erectus was the first Homo species to move out of Africa.

-Their large bodies and well adapted pelvic girdles made them better bipedal runners and walkers over long distances than H.sapiens (3)

12.4 -Large brains/skulls compared to their body mass -Olfactory brain centres reduced/reduced sense of smell


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-Parts of the brain that process information from the hands and eyes are enlarged -Eyes in front/binocular vision/stereoscopic vision -Eyes with cones/colour vision -Freely rotating arms -Long upper arms -Elbow joints allow rotation of forearm -Rotate hands at least 1800 -Flat nails instead of claws/bare finger tips -Opposable thumbs which work in opposite direction to their fingers -Upright posture -Sexual dimorphism/distinct differences -Two teats only (Any 4 x 1) (4)

Question 13 Human evolution 13.1

(b) Differences in Feet In A the big toe is close to the other 4 smaller toes/faces forward

In B the big toe is apart/opposable from the other 4 smaller toes/points outwards

OR In A the heel bone is relatively larger and in B it is relatively smaller OR In A the bones in the foot are straight and in B they are curved OR

In A phalanges are relatively shorter and in B they are relatively longer any 1 x 2

(Mark first ONE only) (2)


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13.2 A (1) 13.3 Foramen magnum in more towards centre of skull in A OR Foramen magnum in more towards the back of skull in B (2)


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Solutions to Paper 1 Topic 3: Genetics Question 1 [Pedigree chart] 1.1 10√ (1) 1.2 Heterozygous√ (1) 1.3 Bent little finger√ (1) 1.4 Only two parents showing dominant features√ can produce offspring showing

both√ phenotypes√ / bent and straight little finger√ OR Two parents with straight little fingers√ must be homozygous recessive√ to produce offspring all with only straight little fingers√ (3)

1.5 25 √% √ / 1/4 (2) 1.6 No√ (1) 1.7 - G is male and F is female√ / different sexes/ non-identical/ fraternal - F has a bent little finger and G has a straight little finger√ (2) Question 2 [Karyotype] 2.1 Female√ (1) 2.2 Has two X chromosomes√ /XX / chromosomes number 23 are similar/ No Y chromosome (1) 2.3 Down's√ Syndrome/ trisomy 21 (1) 2.4 Carries 3√ chromosomes on number 21√ (2) Question 3 [Pedigree chart] 3.1 (a) B√ (1) (b) b√ (1) 3.2 1√ 2√ 8 √ (3)

(Mark first THREE only) Question 4 [Monohybrid] 4.1 2 - Black√ 4 - White√ (2) 4.2 1BB:2Bb:1bb√ / 1:2:1 (1) 4.3 12√ / all / 100% (1) 4.4 (Remember use format) P1 phenotype Black x Black√ Genotype Bb x Bb√ Meiosis G B b x B b Fertilisation F1 genotype BB Bb Bb bb√ Phenotype Black and White√ Parents and offspring√ / P1 & F1 Meiosis and fertilisation√


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OR

gametes B B B BB Bb b Bb Bb

(1 mark for correct gametes, 1 mark for correct genotypes) Question 5 [Blood groups] 5.1 (a) O√ (1) (b) AB√ (1) 5.2

OR


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NOTE: If the wrong type of graph is drawn: marks will be lost for 'correct type of graph'. If graphs are not drawn on the same system of axes, mark the first graph only using the given criteria. Question 6 [Blood banks] 6.1 Get parental consent√ / permission from education department Determine what sample size is appropriate√

Random sample must be taken√ Arrange for all necessary equipment √ / personnel/ budget needed to be available Inform school of the day and time√ that the research will take place Draw up a table√ / recording sheet to record information (4)

(Mark first FOUR only) 6.2 Personnel should wear gloves√

Use new syringes√ / lancets/ cotton wool etc. for every learner tested Have written parental consent from each learner in the sample √ (3)

(Mark first THREE only)

Question 7 [Genetic engineering] 7.1 Available worldwide√

Children / people like to eat it√ Nutritious √ / contains carbohydrates, vitamins, etc. Can be locally grown√ (3)

(Mark first THREE only) 7.2 Risk to human health not yet known√

Religious objection to genetic engineering√ Do not eat bananas/ allergic to bananas√ Increase price of bananas√ Shelf life of bananas / vaccine√ (3)

(Mark first THREE only)


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Question 8 Stem cells Possible answer: rise to different types of cells (2) Source: Embryo / frozen embryo√ Blood in umbilical cord / cord blood√ Placenta√ Bone marrow√ (2)

(Mark first TWO only) Arguments for use of stem cells - Provide replacements for tissues√ damaged by age√ / trauma/disease -Used for research√ to see whether it can cure different diseases √ e.g. cancer -Stem cells from e.g. the blood from the umbilical cord can be stored√ when needed in future because it would no be rejected√ by the body's immune system any 2 x 2 (4)

(Mark first TWO only) Arguments against use of stem cells

- Expensive research money could be used for other need - Only rich people / expensive can afford to store stem cells for later use - Interfere with creation / Immoral we cannot play God / Relgion / Cultural - Can lead to illegal trade in the placentas of new-born babies to make - Money - Babies conceived and then aborted / abandoned / unwanted to use the stem cells from the placenta any 2 x 2 (4)

(Mark first TWO only)

Synthesis (3) (15)


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Paper 2 Topic 1: Life Processes Question 1 Adapted from June, 2009, P2 HG, 1.1.

1.1 Provide the number on the stem where the concentration of Auxin will be

highest (1)

1.2 How will this influence the growth of the stem? (2) 1.3 What conclusion can be made because of this? (2)

Question 2 Adapted from June, 2008, P2 hg, 1.1.2 1.1.3 The tip of an actively growing seedling was removed and then placed on one side of the stem as shown in the diagram below. The seedling was kept in a dark room.

2.1 Provide a hypothesis for this experiment. 2.2 Explain the result and conclusion of this experiment. Question 3 Adapted from Exemplar, 2011, P2, 2.3 A group of Grade 12 learners wanted to investigate the effect of light coming from one direction on the growth of shoots. They planted some wheat seeds in two seed trays and allowed it to germinate. When young shoots appeared above the soil level,


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the shoots were exposed to light from all directions for three days. After three days, the trays received different treatments as follows: Tray A: The shoots were exposed to light from all directions. Tray B: The shoots were exposed to light from one direction only. The diagrams below show the effects of these treatments. Study it and answer the questions that follow.

3.1 Formulate a hypothesis for the investigation above. (3) 3.2 Explain why it was important to include tray A as part of this investigation. (2) 3.3 State ONE conclusion that may be drawn from this investigation. (2) 3.4 A third tray (C) was set up in a similar way as tray A and tray B. The tips of

the shoots were covered with aluminium foil. The diagram below shows the appearance of the shoots at the start and after being exposed to light from one direction only.

What conclusion can you draw from the results obtained in tray C? (2) 3.5 Name ONE use in agriculture of the following:

Auxins (1) Gibberellins (1)


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Question 4 Explain how roots how auxins cause roots to grow downwards (towards gravity). (5) Question 5 The diagram below illustrates the structure of the central nervous system and part of the spinal cord of a person who has had an accident. Study the diagram and answer the questions that follow:

5.1.1 Label numbers 1, 2, 3 and 9. (4) 5.1.2 Give the number(s) of the part(s) responsible for the following responses in

this person: (i) Deep breathing (ii) Controlling high body temperature (iii) Increased pulse rate (iv) Loss of memory (8)

5.1.3 In order to determine the condition of the person, a doctor examined fluid taken from between the parts marked 11 and 12. (i) Identify parts 11 and 12. (2) (ii) Name the fluid present between 12 and 13. (2) (iii) Give TWO functions of the above-mentioned fluid. (2)

5.2. Explain how the following affect the nervous system: i) Dagga ii) Tik (4)


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Question 6 Adapted from exemplar, 2011, P2, 1.4 The diagram below shows the human brain (longitudinal section), spinal cord (transverse section) and the right leg.

6.1 Name part 1, 4 and 5. (3) 6.2 Identify the type of response indicated by the leg lifting up as indicated in the

diagram. (1) 6.3 Explain fully how this response occurs in the body. (5) 6.4 Tabulate the structural and functional differences between parts indicated by

3 and 4. (5) Question 7 Adapted from Nov, 2003, Physiology, 1.3 Copy the table below in your answer book. Complete the following table on the human eye by, under A, adding the numbers of the diagram below the table next to the appropriate label and, under B, making a tick () if the statement under B is TRUE or a cross (X) if the statement is FALSE in respect of each part.

Part of Eye A B = Refracts light rays

1.Vitreous humor

2. Retina

3. Cornea

4. Iris

5. Blind spot

6. Pupil

7. Sclera

8. Lens

9. Conjunctiva

10. Choroid


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Question 8 Adapted from June, 2010, Biology, 2.1 Study the diagrams and answer the questions.

8.1 Name the process that accounts for the change from Diagram I to Diagram II. (1) 8.2 Using letters and names of the parts labelled A to E, describe THREE

changes that occur during the process named in QUESTION 8.1. (9) 8.3 Which diagram (I or II) represents the state of the eye when a person is

reading a book? (1) 8.4 Explain why some people, over the age of 40, tend to wear glasses with

convex lenses. (5) 8.5 How would a blind person be able to read the questions on this question

paper? (1)


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Question 9 Adapted from June, 2008, Biology p2 HG, 2.2 Study the following diagram of the human ear and answer the questions that follow.

9.1 Identify parts B and G. (2) 9.2 State the function of each of parts C and E. (2) 9.3 Explain:

(a) Why you can often clear a buzzing/humming in the ear by swallowing. (3) b) Why the membrane labelled F is much larger than membrane C. (2)

9.4 A dog has lost part A in an accident. Part A is replaced with a stiff, non-elastic, solid plastic structure. (a) Is the plastic structure as effective as the original ear of the dog? (1) (b) Explain your answer to QUESTION 2.2.4 (a). (2)

9.5 Explain how part D and the retina of the eye function in similar ways. (4) 9.6 Give ONE reason for part D being spirally shaped. (2) Question 10 Adapted from Exemplar, 2011, P2, 3.3 Study the diagram below and answer the questions that follow.

10.1 Identify the parts labelled B, C and F. (3) 10.2 Explain how the pinna of the ear is suited for its function. (4)


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10.3 Write the letter of the part which: (a) Contains receptors for balance. (b) Equalises pressure on either side of part B. (c) Transmits impulses to the brain. (3)

Question 11 Adapted from Nov Physiology, 2003, SG, q4 Study the diagrams which illustrate the endocrine glands in the human body.

11.1 Name the one hormone secreted by part labelled 1, 2 and 6. (3) 11.2 Provide the functions of the hormones secreted by the glands found in part

labelled 4. (2) 11.3 Negative feedback occurs between 1 and 4.Explain this mechanism (6)


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Question 12 Adapted from exemplar, 2011, P2, 3.1 Study the diagram below and answer the questions that follow.

12.1 Give labels for the glands numbered 1 and 2. (2) 12.2 Name hormone A. (1) 12.3 Describe the negative feedback mechanism that operates when the thyroxin

level in the blood is too high, as indicated by process C. (4) Question 13 Adapted from June, 2010, Paper2 hg, 1.6


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13.1 Label layer B and part C. (2) 13.2 Write down the letters of TWO parts in the diagram which are involved in the insulation of the body. (2) 13.3 What will happen to part F on a cold day? (2) Question 14 Adapted from Exemplar, 2011, P2, 3.2 The graph below shows the effect of strenuous exercise, followed by a cold shower, on the body temperature of an athlete.

14.1 Which part of the brain responds to the temperature changes that occur at A

and B on the graph? (1) 14.2 What was the maximum temperature reached? (1) 14.3 For what period of time did the person engage in strenuous exercise? (1) 14.4 Why should body temperature not be allowed to fluctuate too much? (1) 14.5 Which diagram (I or II) would represent the condition of the skin after 15

minutes? (1) 14.6 Explain your answer to QUESTION 14.5. (2)


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Paper 2 Topic 2: Environmental Studies Question 1 (Population Ecology) 1.1 Various possible answers are provided for each question. Indicate the

correct answer by writing only the letter of your choice next to the relevant question number.

1.1.1 A population consists of… A different ecosystems. B communities of different organisms. C individuals of the same kind. D different species. 1.1.2 Which of the following represents a population? A Different types of animals in a nature reserve. B Cats and dogs in the backyard of your home. C All the fish in the sea. D All the trout in the Vaal river. 1.2 Give the correct biological term for each of the following descriptions. Write

only the term next to the relevant question number. 1.2.1 The phase during population growth where animals adapt to their new

environment. 1.2.2 The maximum number of organisms of a particular kind that can be supported

by resources in the environment. 1.2.3 The natural ability of a population to increase in size. 1.2.4 One-directional movement of organisms into a population. 1.2.5 A population without emigration and immigration. 1.2.6 Determining the population size by counting all organisms.


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1.3 For each of the phrases in COLUMN I, state whether it applies to A only, B only, both A and B or none in COLUMN II. Write down A only, B only, both A and B or none in the answer book.

COLUMN I COLUMN II

1. Maximum number of individuals an environment can sustain

A. Natality B. Carrying capacity

2. Direct technique A. Petersen method B. Quadrat method

3. Displays exponential growth A. Geometric growth form B. Logistic growth form

1.4 Study the diagram below and answer the questions that follow.

1.4.1 Identify the growth from illustrated above. 1.4.2 Identify the phases labelled A to D. 1.4.3 Briefly explain phase A. 1.4.4 Which phase is NOT illustrated above?

A

B

C

D


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1.5 The graph below shows the number of bacteria growing in a nutrient medium which was kept at a constant optimum temperature for a period of 30 hours.

1.5.1 How many bacteria were present at 10 hours? 1.5.2 From the fifth hour, how long did it take the bacteria population to double in

size? 1.5.3 At which of the following time periods was the growth rate the greatest? Write

only the letter of your choice. A 0 - 5 hours

B 5 - 10 hours C 10 - 15 hours D 15 - 20 hours 1.5.4 Give a possible reason for the increase in growth rate for the period

mentioned in Question 1.5.3. 1.5.5 For how many hours was the population of bacteria found to be above 4000? (Show calculations) 1.5.6 Give ONE possible reason why the population of bacteria suddenly began to decrease after 25 hours. 1.6 A biologist wants to determine the number of trout in an aquatic population.

He caught 25 trout and tagged them. The trout was released. Few months later, he catches 15 trout of which 5 were tagged.


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Question 2 (Human Populations) 2.1 Various possible answers are provided for each question. Indicate the correct

answer by writing only the letter of your choice next to the relevant question number.

2.1.1 What was the population size when the industrial revolution started? A 100 000. B 1000 000. C 1000 000 000. D 2000 000 000. 2.1.2 According to the graph, what event lead to a significant decrease in the

human population? A Industrial revolution B Bubonic plaque C Agricultural revolution D Bronze age


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2.2 Study the population pyramid of the South African population. 2.2.1 What does a population represent? 2.2.2 What is represented by the horizontal axes? 2.2.3 What is represented by the vertical axes? 2.3 Study the population pyramids of different populations. 2.3.1 What is the percentage of females between 0 - 4 in pyramid A?

2.3.2 What is the percentage of males between 35 - 39 in pyramid B? 2.3.3 What is the percentage difference between age groups 15-19 and 25-29? 2.4.1 What is the age group between 15 - 44 called?


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2.4.2 Give only the letter of the population pyramid that has: (a) the same natality and mortality rate (b) a decreased natality rate and low mortality rate (c) a high natality and mortality rate (d) the slowest population growth rate 2.4.3 Which population pyramid (only letter) could represent the population of: (a) South Africa (b) Italy (c) United States 2.4 Study the statistics of the South African population. 2.4.1 Calculate the percentage of the population for each province. 2.4.2 Calculate the total South African population.

Province Population size Percentage

Eastern Cape 6 743 800

Free State 2 824 500

Gauteng 11 191 700

KwaZulu-Natal 10 645 400

Limpopo 5 439 600

Mpumalanga 3 617 600

Northern Cape 1 103 900

North West 3 200 900

Western Cape 5 223 900

Total


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2.5 Study the map of the world that indicates the ecological footprints of the different countries. The darker the colour, the greater the ecological footprint.

2.5.1 What is meant by the term “ecological footprint”? 2.5.2 State the units that are used to measure ecological footprints. 2.5.3 Which country has the greatest ecological footprint? 2.5.4 Provide TWO possible reasons why the country mentioned in QUESTION

2.5.3 has the greatest ecological footprint? 2.5.5 Which southern hemisphere country has the greatest ecological footprint? 2.5.6 What will happen in South Africa if the ecological footprint is not kept less than

the biocapacity? 2.6 Write an essay discussing THREE strategies the learners of South Africa could use to combat (lessen) our ecological footprint on the South African environment.


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2.7 Study the population pyramids of different populations. 2.7.1 What colour in the pie graphs indicates numbers of developed countries? 2.7.2 Provide reasons for your answer.


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Question 3: Community Ecology 3.1 Various possible answers are provided for each question. Indicate the correct

answer by writing only the letter of your choice next to the relevant question number.

3.1.1 Which of the following serves as the best example of predation? A Bees visiting a flower B Ticks on a dog C A lion catching a zebra D A bird’s nest in a tree 3.1.2 Which ONE of the following statements is TRUE about the relationship

between a predator and its prey? A There is interspecific competition B The size of the predator population is density dependent and is

controlled by the size of the prey population C An increased number of predators causes an increased number of prey D A decreased number of predators causes a decreased number of prey 3.2 Give the correct biological term for each of the following descriptions. Write

only the term next to the relevant question number. 3.2.1 An organism that only consumes plant material. 3.2.2 Group of organisms that live off dead organisms. 3.2.3 Type of competition between members of the same species. 3.2.4 Competition between organisms that ensures that the best competitor stays in

the environment. 3.2.5 Coexisting of lions and leopards in the same area.


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3.3 Study the diagrams below and name the type of social organization and its benefit to the population.

3.4 Study the graph below of the interaction between two populations of mites

namely genus’s Typhlodromus and Eotetranychus, and answer the questions that follow.

3.4.1 Name the type of interaction illustrated in the graph. 3.4.2 Provide the complete scientific name of the prey. 3.4.3 Provide the complete scientific name of the predator. 3.4.4 What is the number of prey at week 5? 3.4.5 What is the number of predators at week 55? 3.4.6 Describe and explain the pattern shown by the interaction in the graph. 3.4.7 Create a table to indicate the population size of the two species from day 20

to day 40.


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3.5 Study the diagrams below and name the type of competition with reasons.

3.6 Study the diagrams below and name the type of social interaction is

illustrated. Briefly describe the relationship.

3.7 Study the diagrams below and name the type of social interaction isillustrated. Briefly describe the relationship.


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3.8 Source: 2011, Life Sciences paper 2 Exemplar, Question 4.2 Read the paragraph below on the culling of elephant TOO HUNGRY, TOO DESTRUCTIVE, TOO MANY: SOUTH AFRICA TO BEGIN ELEPHANT CULL An elephant herd at the Kruger National Park has 20 000 elephants, 5 000 more than is sustainable. Ecologists say the animals' huge appetites and fondness for 'habitat re-engineering' - reducing forests to flatland by uprooting trees and trampling plants - is the main problem. Culling of the excess elephants is seen as an advantage in that it generates revenue for the communities from the sale of ivory and other elephant products. It will also provide meat to the local communities. Alternatives to culling include contraception and relocation of entire elephant families. The removal of fences between the Kruger National Park and parks in neighbouring Mozambique will eventually help with migration into less congested areas. The 1998 figure of 8 000 elephant increased to 20 000 in 2008 and it is expected to reach 34 000 by 2020. [Adapted from The Guardian, 26 February 2008] 3.8.1 Give the main reason mentioned above in support of the culling of elephants. 3.8.2 Name TWO alternatives to culling proposed above. 3.8.3 Draw a bar graph to show the change in the elephant population from 1998 to

2020. 3.9 Source: 2011, Life Sciences paper 2 Exemplar, Question 4.3 Using examples, describe predation, competition and symbiosis, explaining how each interaction influences the population size of the organisms involved.


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Question 4: Ecology Succession 4.1 Study the diagram below and answer the questions that follow.

4.1 What biological process is illustrated above? 4.2 Differentiate between primary and secondary versions of the above-mentioned process. 4.3 What do we call the first species that occupy barren or bare soil?


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Paper 2 Topic 3: Reproduction Question 1 Adapted from Exemplar , 2011, Paper 2,Question 1.5. Study the diagram below of the life cycle of a plant in which the gametophyte generation is dominant

1.1. Is the life cycle represented, that of a moss or a flowering plant? (1) 1.2. Name the following:

a) Cell division A b) Process B c) Cell division C (3)

1.3. Is the gametophyte haploid or diploid? (1) 1.4. Are seeds produced during the life cycle of this plant? (1)

male gamete (n)

gametophyte

male sex organ (n)

female sex organ (n)

cell division A

female gamete (n)

process B zygote

sporophyte

cell division C

spores (n)


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Question 2 Adapted from February, 2011, Paper 1, Question 3.3. Study the diagram of a flower below and answer the questions that follow

2.1. Label parts A, B and D (3) 2.2. Describe TWO ways how the structures in a flower are adapted for each of

the following: a) Wind pollination (2) b) Insect pollination (2)

2.3. What do the following structures develop into after fertilisation? a) Structure C b) Structure E (2)

2.4. Give the letter/s of the parts that forms part of the: a) male whorl b) female whorl (4)

Question 3 Adapted from Feb/Mar 2011, Paper 1, Question 3.1. The diagram below represents the female reproductive system.


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3.1. Label structures A, B and C (3) 3.2. State THREE functions of D (3) 3.3. Fertilisation usually takes place at Y. Why will a blockage at X:

a) Prevent fertilisation at Y (1) b) Not necessarily lead to infertility (2)

Question 4 Adapted from Exemplar, 2011, Paper 2, Question 2.1. Study the diagram below showing the sequence of events of the development of an ovum in a 28-day cycle

4.1. Identify the following:

a) Follicle labelled A b) Structure labelled C c) Process shown at B d) Hormone responsible for the formation of part A e) Hormone responsible for the formation of part C (5)

4.2. What type of cell division resulted in the formation of part D? (1) 4.3. If the events shown above took place in a 28 day cycle, state whether

fertilisation took place during this period. (1) 4.4. Explain your answer to question 4.3. (3)

4.5. Explain HOW and WHY the production of FSH is inhibited when fertilisation takes place. (4)

A

C

B

D


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Question 5 Adapted from November, 2010, Paper 1, Question 3.1. The diagram below shows part of the female reproductive system. Structures B to G and processes 1, 2 and 3, occurring in the Fallopian tube and uterus are magnified.

5.1. Label C and D. (2) 5.2. State which processes are taking place at 1, 2 and 3 respectively. (3) 5.3. State how many chromosomes are present in the following structures:

a) E b) Each cell of structure G (2)

5.4. Draw an enlarged labelled diagram of structure F to show its details. (5) 5.5. State TWO functions of fluid A. (2) 5.6. Structure B transports substances to and from the foetus.

a) Name ONE useful substance transported to the foetus. b) Name ONE waste product transported from the foetus. (2)


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Question 6 Adapted from September, 2009 (Free State) , Paper 1, Question 1.4. Study the diagram below which shows the male reproductive system and answer the questions that follow.

6.1. Provide a label for part E. (1) 6.2. State ONE function of part:

a) A b) D c) E d) G e) H (5)

6.3. Explain the function that parts B and C have in common. (2) 6.4. Write down the LETTER of the part in which meiosis occurs and name the

type of cells that forms at the end of the process. (2) 6.5. Name the cells found in structure G that are responsible for the production of

Testosterone. (1) 6.6. Describe a permanent contraceptive method in males. (2)


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Question 7 Adapted from June, 2009 (Gauteng) , Paper 1, Question 4.2. The following questions refer to the figures below, which illustrates the changing of hormones; the ovarian cycle and the changes of the endometrium during the menstrual cycle. Study the figures and answer the questions that follow.

7.1. Identify the hormones A, B, C and D. (4) 7.2. Explain why the structure of H changes so much from day 4 to day 28. (1) 7.3. Give TWO reasons why menstruation takes place. (2) 7.4. What causes hormone B to peak at day 14. (1) 7.5. Name the hormone that is secreted by G. (1) 7.6. Why do the levels of hormone C begin to rise steeply after day 14 on the

graph. (1)


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Solutions to Paper 2 Topic 1 Life Processes Question 1 Plant Hormones 1.1 1 (1) 1.2 It will cause the stem to bend towards the light (2) 1.3 Stems are positively phototropic (2) Question 2 Plant Hormones 2.1 Stems are positively/negatively phototropic (3) 2.2 Result - stem will bend to the left

Conclusion - substances which promote growth are formed at the tip of the stem. (3)

Question 3 Plant Hormones

3.1 Shoots will grow towards the light OR Shoots will grow awayfrom the light OR Light has no influence on the shoot (3) 3.2 It is the control - To verify the results of the experiment./To allow for one variable only. (2) 3.3 Shoots grow towards the source of light. (2) 3.4 The auxins that make the shoot to grow towards the light is in the tips of the shoots . (2) 3.5 (a) Apical dominance (1) (b) Tall growth of a plant/stimulate seed germination (1)

Question 4 Plant Hormones Under the influence of gravity, Auxins settle at the bottom of the root. A high concentration of Auxins here (in the root) inhibits cell division and elongation. The cells on the upper end grow faster and the root bends downwards. Roots are therefore positively geotrophic.


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Question 5 Nervous System 5.1.1 1 - cerebrum 2 - cerebellum 3 - spinal cord 9 - medulla oblongata (4) 5.1.2 i) 9 ii) 6 iii) 9 iv) 1 (8) 5.1.3 i) 11 - pia mater 12 - arachnoid (2) ii) cerebro-spinal fluid (1) iii) protection distribution of nutrients (2) 5.2 (i) Mood swings, memory loss (2) (ii) Wild rages, anxiety, paranoia (2) Question 6 CNS Reflex Arc 6.1 1 - cerebrum 4 - motor neuron 5 - cerebellum (3) 6.2 Reflex Action (1) 6.3 When hammer knocks knee receptor converts stimulus into impulse Impulse then taken via sensory neuron And enters the spinal cord via dorsal horn of grey matter Makes a synapse with an interneuron which in turn makes a synapse With a motor neuron which leaves via the ventral horn of grey matter Taking the impulse to the muscle (effector) causing it to contract Pulling the leg up - knee jerk reflex (max 5) (5) 6.4

Sensory neuron Motor neuron

Structural differences Unipolar Multipolar

Functional differences Transfers impulses from receptors to CNS

Transfers impulses from CNS to effectors

(5) Question 7 Eye

(20)

Part of Eye A B = Refracts light rays

1.Vitreous humor 10

2. Retina 9 X

3. Cornea 1

4. Iris 5 X

5. Blind spot 8 X

6. Pupil 3 X

7. Sclera 11 X

8. Lens 2

9. Yellow spot 9 X

10. Choroid 12 X


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Question 8 Eye 8.1 (eye) accommodation (1) 8.2 the ciliary muscles , part A contracts

the suspensory ligaments , part B slackens the lens E becomes more convex OR the ciliary muscles , part A relaxes the suspensory ligaments , part B become taut the lens E becomes less convex (9)

8.3 Diagram II (1) 8.4 With old age the lens loses its elasticity / the ability to become more convex / ability to change shape image focusing behind the retina/image not focussing on retina The convex lenses of the glasses allows the light rays to converge on the retina thus forming a clear image. (5) 8.5 It would be in Braille (1)

(17) Question 9 Ear 9.1 B: Semi-circular canals G: Auditory meatus/canal (2) 9.2 C: Transmits pressure waves to the perilymph of the inner ear E: Prevents pressure build-up of sound waves / distortion /eases vibrations out of the inner ear/ absorbs vibrations (2) 9.3 (a) - A buzzing sound is caused by a difference in the pressure between the outer and the middle ear - Swallowing opens / closes the Eustachian tube - to equalise the pressure (3) (b) - To amplify sound (2) 9.4 (a) No (1) (b) It is not moveable or flexible for more accurate collection of sound / for finding the direction that the sound is coming from (2) 9.5 - Both receive stimuli - and convert to impulses - which they send through the sensory neuron Any (2 x 2) (4) 2.2.6 - Larger surface area - to accommodate more receptors - fits into smaller area / takes up less space Any 2 (2)

(18)


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Question 10 Ear

10.1 B - tympanic membrane C - malleus/hammer F - cochlea 10.2 Has many ridges to direct the sound waves along the auditory canal Extends outside the head/large flaps/funnel shaped to trap sound waves (Mark first TWO only) (any 2) 10.3 (a) D (b) G (c) E

(3) (2) (3) (8)

Question 11 Endocrine System 11.1 1 - Growth hormone/FSH/LH/TSH/ ADH any 1 2 - thyroxin 6 - adrenalin/aldosterone any 1 (3) 11.2 Insulin - lowers blood sugar level Glucagon - increases blood sugar level (4) 11.3 High thyroxin concentration in the blood will stimulate the pituitary gland to secrete less TSH. The lower level of TSH will make the thyroid gland to secrete less thyroxin which will decrease the level of thyroxin in the blood (6) Question 12 Endocrine System 12.1 1 – pitituary gland 2 – thyroid gland 12.2 Thyroid stimulating hormone/TSH High thyroxin concentration in the blood will stimulate the pituitary gland to secrete less TSH. The lower level of TSH will make the thyroid gland to secrete less thyroxin which will decrease the level of thyroxin in the blood (any 4)

(2) (1) (4) (7)

Question 13 13.1 B – Epidermis C – Erector muscle (2) 13.2 A D (2) 13.3 Constrict (1) (5)


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Question 14

14.1 Hypothalamus 14.2 37,5 oC 14.3 10 minutes 14.4 Most human activities is controlled by enzymes and enzymes require optimum temperatures to function 14.5 Diagram I 14.6 Blood vessels dilated to bring more blood to the surface and more heat will be lost. OR Increased sweat productionwhich will cool down the body

(1) (1) (1) (1) (1) (2) (7)


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Solutions to Paper 2 Topic 2: Environmental Studies Question 1 (Population Ecology) 1.1.1 C 1.1.2 D 1.2.1 Lag phase 1.2.2 Carry capacity 1.2.3 Natality 1.2.4 Immigration 1.2.5 Closed 1.2.6 Census / Direct method 1.3.1 B only 1.3.2 Neither A or B 1.3.3 Both 1.4.1 Logistic growth form 1.4.2 A - lag phase

B - exponential growth phase C - decelerating growth phase D - equilibrium / stationary phase

1.4.3 - Organisms are new to the environment - it needs time to adapt to environmental conditions - also new food sources 1.4.4 Extinction phase 1.5.1 1000 per mm 1.5.2 2,5 hours 1.5.3 C 10 - 15 hours 1.5.4 Bacteria have adapted to environment 1.5.5 30 -14 = 16 1.5.6 Exceeded carrying capacity / High environmental resistance 1.6 M x C N = R N = Population size M = Number captured during first catch C = Number captured during second catch R = Number of tagged organisms 25 x 15 N = 5 = 325 5 = 125 trout


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Question 2 (Human Populations) 2.1.1 C 2.1.2 B 2.2.1 Percentage of a specific gender of a population according to different age

groups 2.2.2 Percentage of the population 2.2.3 Different age groups 2.3.1 8 2.3.2 4.2 2.3.3 = 4 - 2 = 2% 2.4.1 Reproductive 2.4.2 (a) C (b) B (c) A (d) B 2.4.3 (a) A (b) C (c) B 2.4

Province Population size Percentage

Eastern Cape

13,5

Free State

5,7

Gauteng

22,4

KwaZulu-Natal

21,3

Limpopo

10,9

Mpumalanga

7,2

Northern Cape

2,2

North West

6,4

Western Cape

10,4

Total 49 991 300


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2.5.1 The ecological footprint compares human demands with the planet’s ecological capacity to meet those demands.

2.5.2 Global hectares 2.5.3 USA 2.5.4 It has a great amount of industries Great number of car Not signed Kyoto protocol 2.5.5 Australia 2.5.6 Any TWO of the following:

Collapsing fish stocks

Diminishing forest cover

Depletion of freshwater systems

A build-up of pollution and waste, which creates problems such as global climate change

2.6 Write an essay discussing THREE strategies the learners of South Africa could use to combat (lessen) our ecological footprint on the South African environment.

2.7.1 Green 2.7.2 Has smallest population BUT largest consumption AND hazardous waste

production Question 3 (Community Ecology) 3.1.1 C 3.1.2 B 3.2.1 Herbivore 3.2.2 Saprophytes / heterotrophs 3.2.3 Intraspecific / intraspecies 3.2.4 Competitive exclusion 3.2.5 Resource partitioning 3.3 Fish = confusing predators Zebras = confuse predators African wild dogs = ensure successful hunting Bees = division and specialization of labour 3.4.1 Predation or predator-prey interaction 3.4.2 Eotetranchys sexmaculetus

Criteria Marks allocated

1 2 3

Strategies One valid strategy Two valid strategies Three or more valid strategies

Discussion Valid discussion of one strategy

Valid discussion of two strategies

Valid discussion of three strategies

Synthesis Significant gaps in logic and flow of answer.

Minor gaps in logic and flow of answer.

Well structured – demonstrates insight and understanding of question.


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3.4.3 Typhlodromus occidentalis 3.4.4 +- 100 3.4.5 +- 12 3.4.6 When the number prey increases there is more food available

That means that all the cubs of a lynx litter will receive food and all will reach maturity That increases the predator population As the predator population increases the predation pressure would increasewhich means that the predators will be killing more prey causing a decrease in prey population As the prey population decreases the predators will have less food and their numbers will be decreasing The decrease in predators allows the number of prey to increase

3.5 Lions = intraspecific competition (same species) Lions and hyenas = interspecific competition (different species)

3.6 Mosquito on skin = parasitism (parasite benefits while host is harmed) Nest in tree = commensalism (bird benefits while tree is NOT harmed or benefitted)

3.7 Bee on flower = mutualism (Both bee and flower benefits) Clown fish in sea anemone = mutualism (Both fish and anemone benefits)

3.8.1 Damage to the environment 3.8.2 Contraception

Relocation of elephant families Removing fences to allow migration (Mark first TWO only)

3.8.3

Mark allocation of the graph

0

5000

10000

15000

20000

25000

30000

35000

40000

1998 2008 2020

Nu

mb

er

of

ele

ph

an

ts

Year

Elephant population from 2008 to 2020

Caption for graph 1

Correct label for X-axis 1

Correct label for Y-axis 1

Appropriate scale for Y-axis 1

Drawing of bars (D) 1 mark if 1 to 2 bars are drawn correctly2 marks if all 3 bars are drawn correctly


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3.9

Predation o A predator captures and kills other animals (prey) for its food o Example: Lions that capture and feed on antelopes o Prey population will decrease and the predator population will increase

Competition o Interspecific competition

Happens when large numbers of organisms of different species depend on same resources.

Example: Flour beetles One species will decrease in population size while the other will

increase o Intraspecific competition

Happens when large numbers of organisms of different species depend on same resources.

Example: Flour beetles One species will decrease in population size while the other will

increase o Intraspecific competition

Happens between organisms of same species that share the same available resource.

Example: Owls competing for same resources. Stronger owls will survive

The owl population will decrease Symbiosis is the close association between two organisms so

that one or both benefit o Parasitism

One organism benefit (parasite) while the other is harmed (host) Example: Tapeworm and humans The host organism’s population size will decrease and the

parasite population increase o Mutualism

Symbiotic relationship between two organisms in which both benefit

Example: Bacteria and roots of leguminous plants Both populations will increase

o Commensalism Symbiotic relationship between two organisms in which one

benefits without harming the other Example: Sharks and sucker fish/Remora (benefit) The population size of the organism that benefits will increase in

size


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Marks Description

3 All three interactions discussed with no irrelevant information

2 Two interactions discussed with no irrelevant information OR three interactions discussed with little irrelevant information

1 One interaction discussed with little or no irrelevant information OR two interactions discussed with little irrelevant information

0 Not attempted/nothing written other than question number/no correct information

Question 4 (Ecology Succession) 4.1 Ecological succession 4.2 Primary is when the soil has never supported life but secondary referred to

succession where the environment has been damaged 4.3 Pioneer species


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Solutions to Paper 2 Topic 3: Reproduction Question 1 1.1. Moss (1) 1.2.

(a) Mitosis (b) Fertilisation (c) Meiosis (3)

1.3. Haploid (1) 1.4. No (1) Question 2 2.1. A- Petal

B- Anther C- Stigma (3)

2.2. a) - The pollen grains are light/smooth and dry and float easily - The anthers hang out of the flower / have tall stamens .This will allow for the wind to easily carry off the pollen grains. - The stigmas are large and feathery/sticky , which helps to trap the pollen grains easily - The flowers produce large amounts of pollen , to increase the chances of pollination

Mark first TWO only (2)

b) - The flowers are brightly coloured and scented to attract insects . - The flowers are usually large /smaller flowers are grouped together to be more attractive to the insects . - The pollen grains are rough and /or sticky so that they can easily become attached to the insects. - Some flowers have special mechanisms that allow the stamens to touch the body as soon as an insect lands on the petals. - The flowers have a larger area that serves as a "landing pad" for insects

Mark first TWO only (2) 2.3.

a) Seed b) Fruit (2)

2.4. a) B b) C D E (4)

Question 3 3.1. A- Fallopian tube/ Oviduct

B- Ovary C- Vagina (3)

3.2. - Encloses and protects the developing embryo/foetus - Forms part of the placenta


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- which provides for the nutrition/gaseous exchange /excretion of the embryo - Allows for implantation /attachment of the embryo - Contracts during labour for childbirth

Mark first THREE only (3) 3.3.

a) The sperm will be prevented from reaching the ovum /prevents the ovum from travelling along the Fallopian tube (1) b) The ovum produced in the other ovary can still be fertilised in the other Fallopian tube. (2)

Question 4 4.1. (a) Graafian follicle

(b) Corpus luteum (c) Ovulation (d) FSH (e) LH (5)

4.2. Meiosis (1) 4.3. No (1) 4.4. If fertilisation occurred the corpus luteum would stay intact and not be

destroyed (3) 4.5 If fertilisation occurs high levels of progesterone enters the blood

The high levels of progesterone inhibits the production of FSH Low levels of FSH stop the development of a ovum inside a Graafian follicle No ovulation occurs when the individual is pregnant (4)

Question 5 5.1. C- Endometrium /Uterine wall

D- Ovary (2) 5.2. 1- Ovulation

2- Fertilisation 3- Mitosis (3)

5.3. a) 23 b) 46 / 23 pairs (2)


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5.4.

(5)

5.5. - Acts as a shock absorber /prevents physical or mechanical damage - Protects the foetus from drying out - Insulates the foetus against temperature fluctuations - Allows foetal movement for growth and development

Mark first TWO only (2) 5.6. a) Oxygen

(Dissolved) food (examples ; glucose ,amino acids , water) Antibodies Nutrients Mark first ONE only (1) b) Metabolic waste Carbon dioxide Nitrogenous waste/ (examples urea, ammonia, uric acid) Water Mark first ONE only (1)

Question 6 6.1. E - Vas deferens /Sperm duct (1) 6.2. (a) A – Stores urine, temporarily (b) D – carries sperm and urine out of the body (c) E – carries sperm from epididymis to urethra

(d) G – produces sperm and male sex hormones (e) H – Holds the testis away from the body to lower the temperature for

optimum sperm production/acts as temperature regulator (5) 6.3. Both these glands provide secretions that help with the production of

semen/aids the efficiency of sperm (2) 6.4. G , haploid spermatids/sperm cells (2) 6.5. Cells of Leydig /Interstitial cells (2) 6.6. Vasectomy The Vas deferens/sperm duct is cut/severed thereby preventing

sperm from entering into the ejaculatory duct/urethra (1)


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Question 7 7.1. A- FSH

B- LH C- Progesterone D- Oestrogen (4)

7.2. H represents the thickness of the endometrium / uterine lining. Around day 5/6, which is just after menstruation, the lining starts to build up again, as the levels of oestrogen start to increase / This is to prepare the uterus for implantation of a zygote. (1)

7.3. A decrease in progesterone levelsdue to the disintegration of the corpus luteum causes a shedding of the endometrium as fertlisation did not take place Mark first TWO (2)

7.4. A decrease in oestrogen, (after ovulation) (1) 7.5. Progesterone (1) 7.6. Ovulation has occurred and the ovum is now in the Fallopian tubes. If

fertilisation should occur, the endometrium must be ready for implantationProgesterone is responsible for the thickening of the endometrium Mark any 3 (3)

springschool_lifesci1+2

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