Read the following instructions carefully before answering the questions. Start the answers to EACH question at the top of a NEW page.

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1 Life Sciences P2/Grade 12 2 September 2017 INSTRUTIONS N INFORMTION Read the following instructions carefully before answering the questions nswer LL the questions. Write LL the answers in your NSWER OOK. Start the answers to EH question at the top of a NEW page. Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. Make LL drawings in pencil and label them in blue or black ink. raw diagrams, tables or flow charts only when asked to do so. The diagrams in this question paper are NOT necessarily all drawn to scale. o NOT use graph paper. You must use a non-programmable calculator, protractor and a compass where necessary. Write neatly and legibly.

2 Life Sciences P2/Grade 12 3 September 2017 SETION QUESTION Various options are provided as possible answers to the following questions. hoose the correct answer and write only the letter ( to ) next to the question number (1.1.1 to ) in your NSWER OOK, for example The particular position of a gene on a chromosome is called... a locus. an allele. genetics. homologous scientific idea that still has to be tested is referred to as a theory. hypothesis. fact. belief lood group is a result of complete dominance. non-disjunction. incomplete dominance. co-dominance Two complimentary bases in a N strand are held together by strong nitrogen bonds. by weak nitrogen bonds. because they are coiled around each other. by weak hydrogen bonds recessive allele always leads to a genetic disorder. is never expressed in the phenotype. is not expressed in a phenotype when a dominant allele is present. produces the same phenotype when homozygous or heterozygous.

3 Life Sciences P2/Grade 12 4 September ccording to harles arwin, organisms that will be most successful biologically, are those that are best adapted to their environment. are the largest in the population. reproduce the slowest. do not change ring of N (plasmid) is taken from a bacterial cell to produce insulin. The steps which follow below are NOT in the correct order. (i) (ii) (iii) (iv) The gene for insulin is removed from a cell of a human pancreas The bacteria make clones of themselves and produces insulin The insulin gene is put into the plasmid and into a new bacterial cell The bacterial plasmid is cut using enzymes What is the ORRET order of steps? (i), (ii), (iv) and (iii) (iii), (ii), (iv) and (i) (iv), (i), (iii) and (ii) (iv), (ii) (i) and (iii) Which ONE of the following represents molecules that make up a single nucleotide? Phosphate, sugar and a nitrogenous base Sugar, protein and phosphate Nitrogenous base, phospholipid and sugar denine, sugar and a nitrogenous base own syndrome occurs when a male sex cell undergoes mitosis. every cell of an organism has an extra pair of chromosomes. all somatic cells of an organism have an extra chromosome. a female sex cell undergoes mitosis.

4 Life Sciences P2/Grade 12 5 September The following refers to reproduction in different organisms: (i) (ii) (iii) (iv) Infertile offspring reed at the same time of the year Species-specific courtship behaviour displayed in animals Plants adapted to specific pollinators Which of the above are reproductive isolating mechanisms? (i), (ii), (iii) and (iv) (i) and (ii) only (iii) and (iv) only (iii) and (iv) only (10 x 2) (20) 1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.8) in your NSWER OOK n arrangement of black bars representing N fragments that can be used to determine whether people are related The use of biotechnology to produce an individual that is genetically identical to the one from which it was formed diagram showing the evolutionary relationships between species pair of identical chromosomes found in diploid cells The appearance of an organism as a result of its genetic make-up n opening on primate skulls through which the spinal cord passes Tangled network of chromosomes located within the nucleus Segment of a chromosome that codes for a specific protein (8 x 1) (8)

5 Life Sciences P2/Grade 12 6 September Indicate whether each of the descriptions in OLUMN I applies to ONLY, ONLY, OTH N or NONE of the items in OLUMN II. Write only, only, both and or none next to the question number (1.3.1 to 1.3.4) in the NSWER OOK. OLUMN I OLUMN II Two different alleles of a gene are : Incomplete dominance equally expressed in the phenotype : omplete dominance Having a single set of chromosomes : iploid : Haploid Involved in the discovery of N : Watson : Gould ustralopithecines that were found in South frica 1.4 The diagram below represents a phase of meiosis. : Little Foot : Mrs Ples (4 x 2) (8) Provide labels for parts and respectively Identify the phase illustrated above. Give a reason for your answer to QUESTION How many chromosomes would be found in each gamete at the end of this division? How many chromosomes were present in the original mother cell? Give the name of the process responsible for the mixed appearance of structure. State ONE place where meiosis takes place in the male body. (8)

6 Life Sciences P2/Grade 12 7 September Polydactyly (extra finger/toe) is a dominant trait in humans controlled by a single pair of alleles. The pedigree diagram below shows a family in which this trait has occurred. Use F to represent the allele for polydactyly. Normal Female Polydactylous Female Normal Male Polydactylous Male How many of the males in this pedigree diagram are polydactylous? Give the genotype of all normal people shown in this pedigree diagram. an individuals and have a polydactylous child? Give ONE reason for your answer in QUESTION (6) TOTL SETION : 50

7 Life Sciences P2/Grade 12 8 September 2017 SETION QUESTION The diagram below illustrates protein synthesis Name the molecule represented by N Write down the sequence of the FIRST THREE nitrogenous bases on the N strand that led to the formation of Z.

8 Life Sciences P2/Grade 12 9 September 2017 The table below shows the base triplets of N and the amino acid each codes for. ase triplet of N GT G TGT GT T mino acid coded for Serine Glycine Threonine Histidine Valine rginine ysteine With reference to the diagram in QUESTION 2.1 and the table above: (a) State the base sequence of the molecule labelled Q. (b) Name the amino acid labelled P. escribe how the composition of the protein molecule changes if the base sequence at X is UGU instead of U Name and describe the phase of protein synthesis taking place at the ribosome. (5) (12) 2.2 The following diagrams show a process in evolution taking place on an island that split into two parts Name the evolutionary process that resulted from the continental drift shown above.

9 Life Sciences P2/Grade September escribe how the original population of species split to become two species as indicated in the diagrams above. (6) (7) 2.3 The following diagram illustrates two different hypotheses about the origins of Homo sapiens. Homo sapiens Homo sapiens Homo erectus in frica Multiregional hypothesis Homo erectus in frica Out of frica hypothesis Use the information in the diagram to describe the difference between the Multiregional Hypothesis and the Out of frica Hypothesis. escribe how the genetic evidence that is available supports the Out of frica Hypothesis. (4) (4) (8) 2.4 Haemophilia is a sex-linked disorder that causes excessive bleeding due to a lack of the blood clotting protein. The recessive allele responsible for this disorder is represented by X h Show by means of a genetic cross the possible genotypes and phenotypes of the parents and children if a man suffering from haemophilia and a woman who is a carrier of this disorder decide to have children. Explain why this disorder affects mostly males in a family. (6) (3) (9)

10 Life Sciences P2/Grade September Three babies (S, T and U) from three different sets of parents were born in a hospital. TWO of the babies were accidentally swopped. lood groups of the parents were used to establish which baby belonged to which set of parents. The blood groups of the parents and the babies are shown in the table below. LOO GROUPS OF IES PRENTS N IES Mother Father aby Mr and Mrs Khumalo S Mr and Mrs Molefe T O Mr and Mrs ube U O Which TWO babies (from S, T and U) were swopped? Give the possible genotype(s) of Mr Khumalo that could have produced baby S. (4) [40]

11 Life Sciences P2/Grade September 2017 QUESTION Read the passage below. VIN FLU VIRUS etween 19 January and 14 February 2017 the National Health and Family Planning ommission of hina reported a total of 304 human cases of infection with vian Influenza (H7N9). t the time of notification there were 36 deaths. Influenza viruses are found in a variety of animals including birds, pigs and also in humans. New subtypes and strains arise when the virus undergoes genetic mutations. Mutations can sometimes happen when viruses exchange information with each other when different viruses come into contact with one another in a single host. The potential for this type of mutation to occur is greatest when there are many opportunities for the virus to multiply like in large flocks with many infected birds. The virus can spread quickly in crowded conditions and the stressful conditions may also weaken the birds immune system efine the term mutation. What can cause a virus that infects birds, to mutate into a strain that can also infect humans? Name and explain THREE consequences of mutations. alculate the percentage of people that died from the H7N9 virus between 19 January and 14 February. Show LL working. (6) (3) (13) 3.2 Tabulate THREE structural differences between N and RN. (7)

12 Life Sciences P2/Grade September The shell of the banded snail, epaea nemoralis, displays a wide variety of both colour and banding (rings). irds, such as thrushes, eat these snails. The birds break open the shells by striking the snails against a rock. It was found that there were equal numbers of light- and dark-banded snails in a specific habitat where no thrushes were found. population of thrushes was then introduced to this habitat. n investigation was done to determine which colour snails (dark-banded or light-banded) were eaten most by the thrushes. The results are shown below: TIME (YS) NUMER OF ROKEN RK-NE SHELLS FOUN ROUN ROKS NUMER OF ROKEN LIGHT-NE SHELLS FOUN ROUN ROKS ay ay ay ay ay Use the information in the table and draw two line graphs on the same set of axis to show the results from the investigation. (7) Which snails were better adapted to prevent them from being eaten by the thrushes? Use the theory of natural selection to explain the results in the table. How would Lamarck explain the results in the table? Explain why Lamarck's theory is NOT accepted. (6) (4) [40] TOTL SETION : 80

13 Life Sciences P2/Grade September 2017 SETION QUESTION 4 escribe the structural changes to the body that correspond with changes in the diet and the change to bipedalism in the evolution of modern humans and explain the significance of these changes. ontent: Synthesis: (17) (3) (20) NOTE: diagrams. NO marks will be awarded for answers in the form of flow charts or TOTL SETION : GRN TOTL: