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Life Sciences Paper 1

Satisfactory Essays

NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P1 FEBRUARY/MARCH 2011 MARKS: 150 TIME: 2½ hours This question paper consists of 14 pages. Copyright reserved Please turn over Life Sciences/P1 2 NSC DBE/Feb. – Mar. 2011 INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. 2. Write ALL the answers in your ANSWER BOOK. 3. Start the answers 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. Do ALL drawings in pencil and label them in …show more content…

The second slide she filled with a 5% sugar solution. The third slide she filled with a 10% sugar solution. The fourth slide she filled with a 15% sugar solution. The fifth slide she filled with a 20% sugar solution. She transferred the same number of pollen grains from the anthers of a flower into each cavity of the five slides. A cover slip was gently lowered onto the slide. All five slides were placed in a warm incubator and left for one hour. Each slide was then examined under a microscope and the number of pollen tubes in each slide was counted and recorded in the table below. Concentration of sugar solution (%) 0 5 10 15 20 Number of pollen tubes 0 7 11 15 21 1.4.1 Explain why Zama used distilled water in the first cavity slide. (2) 1.4.2 State THREE ways in which this investigation would be improved to get more reliable results. (3) 1.4.3 Copyright reserved Describe a conclusion for the above investigation. (2) (7) Please turn over Life Sciences/P1 1.5 7 NSC DBE/Feb. – Mar. 2011 The diagram below represents a karyotype of a human cell. 1 6 2 3 7 13 14 19 20 4 8 9 10 15 11 16 21 5 12 17 22 18 23 1.5.1 How many chromosomes are present in this karyotype? (1) 1.5.2 Is this karyotype that of a man or a woman? (1) 1.5.3 Give a reason for your answer to QUESTION 1.5.2. (2) 1.5.4

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