FACULTY OFENGINEERING. UNIT: lnstem FIRSTOPPORTUNITY EXAMINATION PAPER. MODERATOR: Mr Petrus Paulus THIS PAPER CONSISTS OF 5 PAGES

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1 namibia UniVERSITY 0 F SCIEnCE AnD TECHnOLOGY Faculty of Engineering T: F: E: eng@nust.na W: Office of the Dean: lnstem FACULTY OFENGINEERING UNIT: lnstem QUALIFICATION: Introduction to Science, Technology, Engineering and Mathematics QUALIFICATION CODE: 04STEM LEVEL: 4 COURSE: Introduction to Biology DATE: November 2016 COURSE CODE: IBL402S SESSION: DURATION: 3 Hours MARKS: 100 FIRSTOPPORTUNITY EXAMINATION PAPER EXAMINER: Mrs Funmilayo J John MODERATOR: Mr Petrus Paulus THIS PAPER CONSISTS OF 5 PAGES (EXCLUDING THIS FRONT PAGE) INSTRUCTIONS 1. The number of marks is given in brackets at the end of each question or part question. 2. Answer all the question. 3. Please write and draw neatly and legibly. 4. Mark all answers clearly with their respective question numbers.

2 Section A- 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 ofthe correct statement/phrase in the ANSWER SHEET provided. Question 1 [14] 1.1 About 25 of the 92 natural elements are known to be essential to life. Meaning none of them should be toxic. Look carefully at the list below, which of these elements below is toxic and is NOT part of the essential elements. A. Oxygen B. Manganese c. Magnesium D. Molybdenum E. Arsenic 1.2 Molecular shape is crucial in biology because it determines how biological molecules recognize and respond to one another with specificity Which ofthe following reasons is NOT a reason for the success of the bi-polar nature of water. (1} A. V- shaped B. reversible reactions C. irreversible reactions D. protons and electrons E. delta 1.3 The atomic mass 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

3 1.4 Which of the following is not a characteristic of prokaryotes? A. DNA B. cell membrane C. cell wall D. endoplasmic reticulum E. only D and C 1.5 A. B. c. D. Which of the following does not occur in mitosis? Condensation ofthe Chromosomes Replication of the DNA Separation of the sister Chromatids Spindle formation E. Separation of the centrosome 1.6 A human cell containing 22 autosomes and ay Chromosome is A. somatic cell of a male B. zygote C. a sperm cell D. 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 A. 3 B. 6 c. 12 D. 24 E The life cycle of a sexually reproducing organism includes: A. mitosis B. meiosis C. fusion of sex cells D. band c E. a 1 b 1 and c 2

4 1.9 Which of the following organelles modifies and packages for secretion the materials produced by the ribosomes? A. the chloroplast B. the golgi apparatus c. the nucleus D. the nucleolus E. the mitochondrion 1.10 In human beings, what is mitosis necessary for? {1) A. growth and repairs of tissues B. formation of the gametes C. maintaining ofthe chromosome number D. the death of unnecessary cells E. both a and c are correct 1.11 The terms phase refers to A. Synthesis of chromosomal proteins during prophase B. DNA synthesis during interphase C. active RNA synthesis in lampbrush chromosome. D. synapses of homologous chromosomes fusion of gametes in sexual reproduction. E. fusion of gametes in sexual reproduction 1.12 At which of the following stages do human skin cell nuclei have 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 breakdown to ADP and phosphate D. provides enzymes for metabolism E. is most energetic when in the ADP 3

5 1.14 Cytokinesis is. 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. E. the merging of cytoplasm Section B- Answer all the questions QUESTION 2 [26) Draw the structure of water molecule-- dipole. List all the classes of food. State the key points of the cell theory. Complete Table 1. (2) (7) (3) (5) Table 1 Micronutrient Deficiency disease/signs Vitamin A Vitamin C Bleeding gums Anaemia Calcium Food source Milk, liver Liver Define balance diet. (2) 2.6 Describe the food relationship between the following organisms in an ecosystem use specific names: Lion- Man Cow- grass Lice- Dog 2.7 What do "self-feeding" autotrophs require from the environment in order to make their own food? (3) 2.8 Which type of microscope would you use to study the detailed structure of an organelle in a human liver cell? 4

6 Question 3 [40] 3.1 Define Population. (2} 3.2 A named species of dolphins was studied in a mark-release -recapture method of estimating population size. In the first photographs and mark programme 850 organisms were recorded. After one month another count of 350 was recorded among which 225 were marked. Calculate the actual estimate population of the dolphins in the ecosystem. (8} 3.3 Draw the nucleus enlarged and label it. (10} 3.4 List the six main features that characterize animal cells. (6} 3.5 List the four main features that characterize plant cells. (4} 3.6 Drosophila is a fruit fly often used in genetic research. Vestigial-short wing is caused by mutation. The normal fly has full wings and has allele represented by the symbol N and the short winged fly is represented n.in a breeding experiment, pure bred normal-winged male flies were crossed with pure bred vestigial-winged female flies. All the offspring had normal wings State the genotype ofthe male parents. (0.5} State the genotype of the female parents. (0.5} State the genotype of the offspring. (1} 3.7 In a second experiment, flies with the genotype Nn (for wings} were allowed to mate together Used a genetic diagram to show this cross. (5} Give the expected ratio of the genotypes of the offspring of the cross. (1} Give the expected ratio of the phenotypes ofthe offspring of the cross. (2} Question 4 [20] Make a large representation of the nitrogen cycle. State three uses of microorganisms. Give one method to control breast cancer. Give one method of controlling prostate cancer. (12} (6} (1} (1} The End 5