FACULTY OF ENGINEERING

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1 FACULTY OF ENGINEERING UNIT: InSTEM QUALIFICATION: Introduction to Science, Technology, Engineering and Mathematics QUALIFICATION CODE: 04STEM LEVEL: 4 COURSE: Introduction to Biology DATE: November 2015 COURSE CODE: IBL402S SESSION: DURATION: 3 Hours MARKS: 100 FIRST OPPORTUNITY EXAMINATION PAPER EXAMINER: Dr Martha Uumati MODERATOR: Dr Jeya Kennedy THIS EXAMINATION PAPER CONSISTS OF 8 PAGES (INCLUDING THIS FRONT PAGE AND PERIODIC TABLE) INSTRUCTIONS 1. The number of marks is given in brackets at the end of each question or part question. 2. Answer all questions. 3. Please write and draw neatly and legibly. 4. Mark all answers clearly with their respective question numbers

2 Question 1: [14] Multiple Choice Questions Evaluate the statements in each numbered section and select the most appropriate answer or phrase from the given possibilities. Fill in the appropriate letter next to the number of the correct statement/phrase in the ANSWER SHEET provided. 1.1 About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? (1) A. carbon, sodium, chlorine, nitrogen B. carbon, sulfur, phosphorus, hydrogen C. carbon, hydrogen, nitrogen, oxygen D. oxygen, hydrogen, calcium, sodium E. carbon, oxygen, sulfur, calcium 1.2 Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom s nucleus? (1) A. atomic mass B. atomic weight C. atomic number D. mass weight E. mass number 1.3 The mass number of an element can be easily approximated by adding together the number of in an atom of that element. (1) A. protons and neutrons B. energy levels C. protons and electrons D. neutrons and electrons E. isotopes 1.4 Which of the following is not a characteristic of prokaryotes? (1) A. DNA B. cell membrane C. cell wall D. endoplasmic reticulum E. only D and C

3 1.5 Which of the following does not occur during mitosis? (1) A. condensation of the chromosome B. replication of the DNA C. separation of sister chromatids D. spindle formation E. separation of the centrosomes 1.6 A human cell containing 22 autosomes and a Y chromosome is. (1) A. a somatic cell of a male B. a zygote C. a sperm cell D. a somatic cell of a female E. an ovum 1.7 If an intestinal cell in a grasshopper contains 24 chromosomes, a grasshopper sperm cell contains chromosomes. (1) A. 3 B. 6 C. 12 D. 24 E The life cycle of a sexually reproducing organism includes; (1) A. mitosis B. meiosis C. fusion of sex cells D. b and c E. a, b, and c 1.9 Which of the following organelles modifies and packages for secretion the materials produced by the ribosomes? (1) A. the chloroplast B. the Golgi apparatus C. the nucleus D. the nucleolus E. the mitochondrion

4 1.10 In human beings, why is mitosis necessary for? (1) A. growth and repair of tissues B. formation of the gametes C. maintaining the chromosomes number in all body cells D. the death of unnecessary cells E. both a and c are correct 1.11 The term S phase refers to. (1) A. synthesis of chromosomal proteins during prophase B. DNA synthesis during interphase C. active RNA synthesis in lampbrush chromosomes D. synapsis of homologous chromosomes E. fusion of gametes in sexual reproduction 1.12 At which of the following stages do human skin cell nuclei have the same DNA content? (1) A. early mitotic prophase; mitotic telophase B. G1 ; G2 C. G1; mitotic telophase D. G1; early mitotic prophase E. G2; mitotic telophase 1.13 ATP (1) A. is an amino acid B. has a helical structure C. is a high-energy molecule that can break down to ADP and phosphate D. provides enzymes for metabolism E. is most energetic when in the ADP state 1.14 Cytokinesis is. (1) A. the same process in plant and animal cells B. the separation of cytoplasm and the formation of two cells C. the final stage of mitosis D. the movement of kinetochores.

5 Question 2 [26] 2.1 Draw the structure for methane; illustrate by Lewis Dot structure. (2) 2.2 List the three domains and six kingdoms of organisms. (5) 2.3 State three key points of the cell theory. (3) 2.4 Complete Table 1. (5) Table 1 Micronutrient Deficiency disease/signs Food source Vitamin A Milk, liver Vitamin C Bleeding gums Anaemia Liver Calcium Define symbiosis. Using Table 2, give a short description of the relationship that exists between the following organisms: (5) Bee and flower Bird and nest in tree Lice and dog 2.5 Table 2 Bee and flower Bird and nest in tree Lice and dog Type of relationship Species benefits Species neutral Species harmed 2.6 What do self-feeding autotrophs require from the environment in order to make their own food? (3) 2.7 Which type of microscope would you use to study: (3) the changes in shape of a living human white blood cell; the finest details of surface texture of human hair; the detailed structure of an organelle in a human liver cell?

6 Question 3 [30] Answer ANY THREE of the following questions 3.1 What is a disaccharide and mention the different types of it and give one example of each where it is found in nature? (10) 3.2 Label the diagram of the plasma membrane from a j in Figure 2. (10) Figure List the six main features that characterise animals. (6) List the general features that characterise plants. (4) 3.4 Drosophila is a fruit fly often used in genetic research. The diagram below shows two different strains of Drosophila. Vestigial wing is caused by a mutation. For wings, the normal allele is represented by the symbol N and the allele for vestigial wings is represented by n. In a breeding experiment, pure bred normal-winged male flies were mated with pure bred vestigial-winged female flies. All the offspring of this cross had normal wings State the genotype of the male parents. (0.5) State the genotype of the female parents. (0.5) State the genotype of the offspring. (1)

7 In a second experiment, flies with the genotype Nn (for wings) were allowed to mate together Use a genetic diagram to show this cross. (5) Give the expected ratio of the genotypes of the offspring of this cross. (1) Give the expected ratio of the phenotypes of the offspring of this cross. (2)

8 Question 4 [30] Sketch and label all parts of the cell cycle. (10) During which portion of the cell cycle is DNA polymerase most active? (1) During which portion of the cell cycle are mrna and proteins mainly produced? (1) If the bladder cells are experiencing uncontrolled division, they are likely to spend abnormally long periods of time in which phase of the cell cycle? (1) In general, which phase of the cell cycle has shorter duration? (1) 4.2 Label the diagram below and state the main functions of the labelled structures. (16) Figure 3 Structure (organelle) A) B) C) D) E) F) G) H) Main function The End