Gr11 LS 05 Term 1 Revision & Consolidation

Grade 11 Life Sciences: Term 1 Revision Question 1: Multiple Choice Question Choose the most correct answer for each of the questions.(4) 1.1 All fungi are A parasitic B pathogens of plants, animal or bacteria C able to photosynthesize D heterotrophic 1.2 Malaria is an infectious disease caused by a single-celled organism carried by female mosquitoes. The mosquito is the A pathogen B vector C agent D disease 1.3 How does immunization against diseases such as diphtheria and polio limit the spread of these infectious diseases? A Immunisation kills the relevant pathogens B Immunisation suppresses or reduces the immune response and associated inflammation. C Immunisation strengthens first-line defence barriers and prevents the entry of the relevant pathogens into the body. D Immunisation reduces the multiplication of the relevant pathogens in immunized hosts and this reduces the chance of other people becoming infected. 1.4 The relationship between Rhizobium and leguminous plants (legumes) represent an example of: A Parasitism because Rhizobium brings about the decay of the legume when it dies, thereby returning nutrients to the soil. B Mutualism because Rhizobium denitrifies the legume, and returns nitrogen gas to the atmosphere. C Parasitism because Rhizobium denitrifies the legume, and returns nitrogen gas to the atmosphere. D Mutualism because Rhizobium provides usable nitrogen for the legume, and the legume provides Rhizobium with organic nutrients.

Question 2 Match each description in Column A with the correct term from Column B. Write the answer (letter only) from column B in the space provided. (7) Column A Answer Column B 2.1. Long strands of a fungus that can A fungi extend over a substrate. 2.2 An opportunistic infection of an B saprotrophs HIV-positive person 2.3 Together with bacteria, fungi of C archae this type break down dead organic matter 2.4 An organism that causes malaria D hyphae 2.5 The kingdom of microbes which E pneumonia produce antibiotics 2.6 Cells that have a membrane F phytoplankton bound nucleus and cell organelles 2.7 Animal-like protista G AIDS H vector I Eukaryote J Plasmodia K Protozoa

Question 3 3.1 To what kingdom do these organisms belong? (1) 3.2 Which of these organisms are autotrophic? Give a visible reason to support your answer. (2) 3.3 Which organism could be considered as being intermediate between plants and animals? Give one visible reason that suggests it is plant-like and one reason why it is animal-like. (3) 3.4 What type of food would be stored in the pyrenoids? Explain your answer. (2) [8]

Question Four 4.1 Antigens exist on cell surfaces. The following diagrams show the different forms of antigens, and their relative distribution found on the surfaces of different strains of Staphylococcus bacteria. You wish to make a single vaccine that will be effective against as many strains as possible of the Staphylococcus bacteria shown. 4.1.1 Which strain would you use to make the vaccine? (1) 4.1.2 Explain your answer in question 4.1.1 (2) 4.2 Students were asked to draw an antibody that would be effective against strain P. The following diagrams were presented by three students. Which student has drawn the most effective antibody against strain P? Explain your answer. (2) 4.3 T lymphocytes play an important role in the human immune system. Name and explain the function of each type of T lymphocyte. (6) [11] Question 5 Nitrate, a common ingredient in fertilizer, is found in surface runoff from agricultural land that makes its way into streams, lakes, and coastal zones and is a leading cause of degraded water quality worldwide. A scientist, Bradley Cardinale, at the University of Michigan investigated how useful algae were at cleaning up pollutants in water. Algae are able to absorb the nitrates from the water thereby decreasing the level. He wanted to investigate whether water that contains a rich mix of species of algae is better at removing nitrate than water with only a single species. Cardinale set up an experiment where he discovered the greater the number of different species of algae present, the less nutrient pollution there was in the water. http://www.futurity.org/earth-environment/biodiversity Accessed 20 Feb 2013

5.1 From the explanation, draw a sketch graph to represent the findings of Cardinale. (4) 5.2 What was the hypothesis of the experiment? (2) 5.3 Name another group of organisms that can be used to clean up pollutants in water such as sewerage. (1) 5.4 Other than being able to absorb certain pollutants, explain why algae play such an important role in ecosystems. (2)

Lesson 5: Term 1 Revision Question 1: Question 1.1. 1.2 1.3 1.4 Answer D B D D Question 2: Question 2.1. 2.2 2.3 2.4 2.5 2.6 2.7 Answer D E B J A I K Question3: 3.1 Protista √ (1) 3.2 Euglena√ chloroplast present √ (2) 3.3 Euglena √ flagellum make it animal like √ chloroplast makes it plant like √ (3) 3.4 starch √ product of photosynthesis √ (2) Question 4: 4.1.1 strain Q √ (1) 4.1.2 It has 4 different antigens √ which would allow it to be effective against all strains √ Cannot use M as it has no antigens to match R (2) 4.2 student Y √ antibody has 2 different shapes allowing it to match up with two of the antigens on P √ (2) 4.3 CD4 cells / helper T cells √ - start the immune response to infections √ Killer T cells √ - destroy body cells infected by viruses and parasites √ Suppressor cells √ - stop the immune response once the infection is over √(6)

Question 5: 5.1 Amount of nitrates in water √ number of species of algae √ shape of graph √ axes correct way around√ (4) 5.2 A greater number of species of algae √ will reduce the most nitrate pollution in fresh water √ (2) 5.3 bacteria √ (1) 5.4 Photosynthesise absorbing CO2 √ and releasing O2 into the atmosphere.√ OR basis of food chain √ as they are producers √ (2) [9]