2.3 Die onderstaande gevallestudie handel oor die probleem van eutrofikasie in ‘n ekosisteem. Lees dit aandagtig deur en beantwoord die vrae wat volg:   Ekologiese gevolge van eutrofikasie (Gevallestudie: Eutrofikasie en dooie sones)   Inleiding Dooie sones is suurstof arm gebiede (hipoksie) in die oseaan waar seelewe, insluitend visse, krappe en mossels, nie kan oorleef nie. In die 1970’s het oseanograwe/ mariene bioloë begin let op toenemende gevalle van dooie sones. ‘n Studie van 2008 het 405 dooie sones wêreldwyd getel. Hipoksie is ‘n natuurlike verskynsel wat gereeld in kuswaters regoor die wêreld voorkom. Gedurende die afgelope 50 jaar het die toename in belangrike besoedelingstowwe van menslike aktiwiteite op land egter baie kusekosisteme uit balans gebring, wat gelei het tot uitgebreide streke vir dooie sones. Die verbruik van skulpvis (bv. Mossels, oesters) uit hierdie dooie sones is een van die mees algemene maniere waarop gifstowwe van alge die gesondheid van die mens kan beïnvloed. Die gifstowwe veroorsaak dat iemand onbevoeg raak weens die verlammende effek van die gifstof en kan veroorsaak dat die persoon sterf weens verlamming van die longe. http://www.coastalwiki.org/wiki/Case_studies/eutrophication    

  SECTION A TOTAL

1.4 The blue button below is linked to a dichotomous key.  Click on the button and use the diagram to answer the following questions. TO VIEW THE DIAGRAM, RIGHT CLICK ON THE BUTTON BELOW AND OPEN IT IN A NEW TAB.    

3.2.1 According to this label:   a) how many Smarties equal one serving? (1)         b) how much saturated fat would you be taking in if you had three servings of Smarties?  (Show your calculations) (3)         c)  Explain the link between saturated fat, cholesterol and atherosclerosis. (3)         d)  According to this label, how many grams of fibre are found in 100g smarties? (1)         e) According to this label, what percentage of the carbohydrates in Smarties, is made up of sugar? (2)      

2.2.1 Verduidelik waarom daar soms na ‘n selakant verwys word as ‘n ‘lewende fossiel’. (2)       2.2.2 Hoe oud word daar gedink is die selakantsoort? (1)       2.2.3 In watter jaar is die eerste selakant ‘herontdek’? (1)       2.2.4 Waarom is mariene bioloë so bekommerd dat die nuwe olieboorplatvorms die selakante sal laat uitsterf? Verskaf drie oorspronklike goed deurdagte redes. (3)       2.2.5 Verskaf drie oorspronklike goed deurdagte redes waarom die olieboorwerk moet voortgaan. (3)      

1.5.6 Is skull E showing a chimpanzee skull or a human skull? Describe THREE features visible on the skull, you used to identify the skull. (4)  

2.1 The blue button below is linked to a diagram showing a geological timescale.  Study it carefully  and then answer the questions that follow. TO VIEW THE DIAGRAM, RIGHT CLICK ON THE BUTTON BELOW AND OPEN IT IN A NEW TAB.    

1.2.2 Name ONE important structure found in parts 1,2 and 3 respectively. (3)

4.2 You work for a Health magazine that targets teenagers, and your job is to answer questions from the readers.  One of your readers wrote in to describe a new diet that he is following in order to lose weight.  The diet states that ALL lipids must be removed from the diet. Formulate your response that will be published in the next edition of the magazine.  Describe the variety of roles that fats play in the body and offer two suggestions on a healthier way to lose weight. (10)

1.2.3. a)  Identify this as being either a plant cell or an animal cell. (1)       b)  The visible presence of which organelle helped you to identify the cell? (1)