GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION 2014 10832 LIFE SCIENCES SECOND PAPER MARKS: TIME: 150 2½ hours 1 Pages 18 P.T.O. LIFE SCIENCES (Second Paper) 10832/14 2 GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION LIFE SCIENCES (Second Paper) TIME: 2½ hours MARKS: 150 INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. 2. Write ALL the answers in the ANSWER BOOK. 3. Start the answer to EACH question at the top of a NEW page. 4. Number the answers correctly according to the numbering system used in this question paper. 5. Present your answers according to the instructions of each question. 6. ALL drawings should be done in pencil and labelled in blue or black ink. 7. Draw diagrams or flow charts only when asked to do so. 8. The diagrams in this question paper are NOT necessarily all drawn to scale. 9. Do NOT use graph paper. 10. You should use a non-programmable calculator, protractor and compass where necessary. 11. Write neatly and legibly. P.T.O. LIFE SCIENCES (Second Paper) 10832/14 3 SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions. Choose the correct answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.8) in your ANSWER BOOK, for example 1.1.9 D. 1.1.1 The three molecules that make up a nucleotide are ... A B C D 1.1.2 water, sugar and a phosphate group. a nitrogenous base, water and sugar. a phosphate group, sugar and a nitrogenous base. water, a nitrogenous base and a phosphate group. A white chicken is bred with a brown chicken. Each offsprings‟ coat colour is brown with white patches. This is an example of ... A B C D a dihybrid cross incomplete dominance co-dominance Mendel‟s law of independent assortment P.T.O. LIFE SCIENCES (Second Paper) 1.1.3 10832/14 4 The diagram below shows the formation of the sperm cells of a fruit fly. Study the diagram and answer the questions that follow. 14 chromosomes in nucleus after mitosis after meiosis How many chromosomes are present in the nucleus of cells K and L respectively? K 7 7 14 14 A B C D 1.1.4 Which one of the following occurs during the first division of meiosis? A B C D 1.1.5 L 14 7 14 7 Alleles for a gene are separated Identical haploid cells are formed Diploid cells, showing genetic variation, are formed Alleles for a gene fuse Down syndrome is the result of a mutation. How many chromosomes are present in a somatic cell of a child with Down syndrome? A B C D 23 27 46 47 P.T.O. LIFE SCIENCES (Second Paper) 1.1.6 5 Which one of the following genotypes is possible in the offspring of a homozygous male with blood group A and a female with blood group B? A B C D 1.1.7 10832/14 IA I A IA i ii IB i Which of the following are used as evidence for evolution? I. Homologous structures II. Biogeography III. Genetics A B C D 1.1.8 Which one of the following serves as evidence of cultural evolution in early Homo species? A B C D 1.2 Only I and II Only I and III Only II and III I, II and III Remains of animals close to a Homo skeleton Remains of ancient tools Male and female skeletons in the same area A large number of Homo skeletons in an area 8x2=(16) Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.6) in your ANSWER BOOK. 1.2.1 The analysis of DNA samples to identify individuals or relationships between individuals 1.2.2 The structure holding two chromatids together in a chromosome 1.2.3 The structure in an animal cell that gives rise to spindle fibres during cell division 1.2.4 The sugar found in RNA 1.2.5 The process during which a DNA molecule makes an exact copy of itself 1.2.6 The theory that describes evolution as consisting of long periods of little/no change alternating with short periods of rapid change. (6) P.T.O. LIFE SCIENCES (Second Paper) 1.3 10832/14 6 Indicate whether each of the statements in COLUMN I apply to A ONLY, B ONLY, BOTH A AND B or NONE of the items in COLUMN II. Write A only, B only, both A and B or none next to the question number (1.3.1 to 1.3.7) in your ANSWER BOOK. 1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6 COLUMN I Desired characteristics are passed on from parent to offspring Having one set of chromosomes in each cell Statement that is a possible explanation for an observation than can be tested by experiment to find out if it is true or not A difference between humans and African apes Nitrogenous bases found in any nucleic acid Example/s of mechanisms of reproductive isolation 1.3.7 Bivalents occur A: B: A: B: A: B: A: B: A: B: A: B: A: B: COLUMN II Artificial selection Natural selection Haploid Diploid Hypothesis Theory Opposable thumbs Stereoscopic vision Cytosine Uracil Adaptations of plants to different pollinators Infertile offspring e.g. mules Mitosis Meiosis 7x2=(14) P.T.O. LIFE SCIENCES (Second Paper) 1.4 10832/14 7 Study the diagrams of three species of zebra. vertical stripe horizontal stripe P.T.O. LIFE SCIENCES (Second Paper) 1.4.1 10832/14 Studies have shown that the hotter the environment, the more stripes zebras have. (a) What type of genetic variation would result in different numbers of stripes? (b) What is a biological species? (c) Which species of zebra lives in the hottest environment? 1.4.2 (1) (2) (1) Occasionally, zebras are born that are almost completely black. The change in appearance is the result of mutation. (a) Give the term that is used to describe the appearance of an organism. (b) Differentiate between a gene mutation and a chromosomal aberration. 1.5 8 (1) (2) (7) The diagrams below shows the upper jaw and skull of organisms A and B. Study the diagrams and answer the questions that follow. Organism 1.5.1 Upper jaw Skull (bottom view) Mention ONE visible difference between the palate shape and teeth (dentition) of organisms A and B. (4) 1.5.2 Identify the organism (A or B) which is more likely to be bipedal. (1) 1.5.3 Explain the choice of your answer to QUESTION 1.5.2. (2) (7) TOTAL SECTION A: 50 P.T.O. LIFE SCIENCES (Second Paper) 10832/14 9 SECTION B QUESTION 2 2.1 The diagram below shows a pair of homologous chromosomes with the positions of three genes R, S and T respectively in the cell of a human female during meiosis. 2.1.1 Name the organ in the human female where meiosis occurs. (1) 2.1.2 Identify the phase of meiosis in which the process represented in the diagram above takes place. (1) 2.1.3 What process occurs at point X? (1) 2.1.4 What is the significance of the process mentioned in QUESTION 2.1.3? (1) 2.1.5 “The sex chromosomes are responsible for the fact that, in human populations, there are approximately as many men as there are women.” Explain why this is true. 2.1.6 Explain why colour blindness, a sex-linked disease, is more often found in men than in women. (3) (3) (10) P.T.O. LIFE SCIENCES (Second Paper) 2.2 10832/14 10 The diagram below shows one stage of protein synthesis. amino acids bond X The table below shows five codons and their corresponding amino acids. Codon CUU GGA CAA GUA CCU 2.2.1 2.2.2 2.2.3 Amino acid Leucine Glycine Glutamic acid Valine Proline Identify the stage of protein synthesis represented in the diagram above. (1) Name the stage of protein synthesis that is NOT shown in the diagram above. (1) Use the information in the table to identify the amino acids numbered 1 and 4 respectively. (2) (4) P.T.O. LIFE SCIENCES (Second Paper) 11 Read the extract below and the information in the graph and answer the questions that follow. Antibiotic peptides occur naturally on the surface of human skin. There is a concern that peptides could damage living human cells. One form of damage is the fragmentation (breaking down) of DNA. Human cells were incubated for 16 hours with each peptide extract A, B, C and D at varying concentrations (2µmol dm-3, 6µmol dm-3, 20µmol dm-3 and 80µmol dm-3 respectively). The amount of DNA fragmentation was then measured and represented in the graph below. Source: T Sigurdardottir et al. (2006). Antimicrobial Agents and Chemotherapy. 50(9). Pages 2983-2989 fragmentation/ x-fold increase DNA DNA-fragmention/x-fold increase over control over control 2.3 10832/14 Graph showing the the amount of DNA fragmentation in peptide Graph showing amount of DNA-fragmentation in concentrations peptide concentration A, B, C and D 25 20 15 10 5 0 2 6 20 80 2 6 20 80 LL-37 A 2 6 20 80 2 6 20 80 LLG B 2 6 20 80 2 6 20 80 GKE C -3 3 Peptide Peptideconcentration concentration/ /mol mol dm dm 2 6 20 80 2 6 20 80 FKR D 2.3.1 Identify the peptide extract that causes the least damage to DNA. (1) 2.3.2 Calculate the percentage increase in DNA damage that results when the peptide concentration of A increases from 2 µmol dm -3 to 6 µmol dm -3. Show ALL working. (3) 2.3.3 What is the highest amount of fragmentation that occurred in the peptide extract C? (1) (5) P.T.O. LIFE SCIENCES (Second Paper) 2.4 10832/14 12 The diagram below represents a nucleic acid molecule. Study the diagram and answer the questions that follow. X 2.4.1 Identify the molecule represented in the diagram. (1) 2.4.2 Give TWO OBSERVABLE reasons for the choice of your answer to QUESTION 2.4.1 (2) 2.4.3 Provide labels for bond X and part 1. (2) 2.4.4 Describe how the molecule mentioned in QUESTION 2.4.1 is able to make copies of itself. (6) 2.4.5 Discuss the contribution that Watson and Crick made to the discoveries that led to the modelling of the molecule represented in the diagram above. (2) (13) P.T.O. LIFE SCIENCES (Second Paper) 2.5 10832/14 13 In a certain species of plant, Acer rubrum (red maple), tallness (T) is dominant over shortness (t) and red (R) fruit colour is dominant over yellow (r) fruit colour. 2.5.1 A plant that is homozygous for both tallness and red fruit colour, is crossed with a plant homozygous for both shortness and yellow fruit colour. List the phenotypes and genotypes of (i) (ii) 2.5.2 2.5.3 P1 generation. F1 generation. If the F1 generation in QUESTION 2.5.1 was interbred, what are the chances of the offspring being short with yellow fruit? State Mendel‟s principle of segregation. (2) (2) (2) (2) (8) [40] P.T.O. LIFE SCIENCES (Second Paper) 10832/14 14 QUESTION 3 3.1 Since 1972, biologists have studied finch populations in the Galapagos Archipelago islands. The graph below shows the change to the number of finches, the rainfall and the number of small seeds over a period of seven years on one island (Daphne Major). Small seeds are abundant in rainy seasons and large seeds are drought resistant Amount of Rainfall (mm), No. of finches, 2 No. of small seeds (mg/m ) Finch population on Daphne Major from 1974 to 1980 Rainfall (mm) Number of finches No. of small seeds (mg per square meter) Time (Years) 3.1.1 In which year was the finch population the highest? (1) 3.1.2 Briefly describe the trend in the finch population from 1977 to 1980. (2) 3.1.3 Name the environmental factor that caused the changes in the finch population described in QUESTION 3.1.2. (1) 3.1.4 Use Darwin‟s theory of natural selection to explain how seed-eating finches with large beaks evolved on Daphne Major island over the period 1977 to 1980. (6) (10) P.T.O. LIFE SCIENCES (Second Paper) 15 The graphs below show the breeding seasons of two species of Monarch butterflies that are phenotypically identical, live in the same habitat and feed on nectar from flowers. Study the diagram and answer the questions that follow. Species B No. of eggs laid per day Species A No. of eggs laid per day 3.2 10832/14 Time (months) 3.2.1 3.2.2 TimeTyd (months) (maande) „Sometimes different but related species do interbreed.‟ Use the information provided to explain how the two species above are prevented from interbreeding. Name TWO reproductive isolating mechanisms other than the one mentioned in QUESTION 3.2.1. (2) (2) (4) P.T.O. LIFE SCIENCES (Second Paper) 3.3 10832/14 16 An investigation was carried out to determine the effect of an antibiotic on two types of bacteria (A and B) that cause TB. The diagram below shows the result of the antibiotic after Day 1 and Day 2 of a five day course to treat TB infection. The bacteria (strains A and B) were cultured in a petri dish at a temperature of 37,5° C. Before administration of the antibiotic on TB bacteria After administration of the antibiotic on TB bacteria Day 1 X Day 2 X 3.3.1 Suggest ONE hypothesis for the above investigation. 3.3.2 Which factors in the above investigation represent the (3) (a) independent variable? (b) dependant variable? (1) (1) 3.3.3 Which bacteria, A or B, is resistant to the antibiotic? (1) 3.3.4 Explain the effect that the antibiotic had on the bacteria after the first and second day of treatment. (2) Name the process that leads to the difference in the population size of bacteria A and bacteria B. (1) Predict the consequence should a person fail to complete the antibiotic course. (2) 3.3.7 Why must the bacteria be cultured at 37,5° C? (2) 3.3.8 State TWO precautions that must be taken to ensure that the results of the investigation are valid. 3.3.5 3.3.6 (2) (15) P.T.O. LIFE SCIENCES (Second Paper) 3.4. 10832/14 17 Study the phylogenetic tree below on brain capacity of hominid species and answer the questions that follow. Mya 3.4.1 3.4.2 Identify the THREE main genera of the hominid species shown in the above illustration. (3) Using the phylogenetic tree, name the common ancestor of H. sapiens and H. neanderthalensis (1) The table below represents the average cranial capacity of hominid species. HOMINID SPECIES AVERAGE CRANIAL CAPACITY (cc) A. afarensis 300 A. africanus 400 H. habilis 700 H. erectus 1 000 H. neanderthalensis 1 400 H. sapiens 1 200 3.4.3 Using the table above, draw a bar graph illustrating the average brain capacity of the hominid species. TOTAL SECTION B: (7) (11) [40] 80 P.T.O. LIFE SCIENCES (Second Paper) 10832/14 18 SECTION C QUESTION 4 4.1 Sandy has given birth to a baby girl. There are two men claiming to be the father of the child. Explain how the inheritance of blood groups and DNA testing could assist in establishing who the father is. Content Synthesis NOTE: (17) (3) (20) NO marks will be awarded for answers in the form of flow charts or diagrams. END TOTAL SECTION C: 20 GRAND TOTAL: 150