Expectations How well you do is dependent on how hard YOU work. You have to take notes by hand in class (and at home) Use the textbook, my website, IB guide, and past exam questions as your resources – Buy the exam question bank! You will only speak English You will ask for help if you need it

Expectations Bring pen/pencil, paper, textbook and laptop to lesson You are to have a binder just for Biology with dividers. This will hold all your handouts, notes in class, and the notes you make

How does the DP Biology work? Core (SL): Topics 1 – 6 (40hrs lab) AHL: Topics 1-11 (60hrs lab) Everyone: 1 option for the exam 7 Prescribed practicals Final exam is broken down to 3 papers (80%) Independent international assessment(IA) (20%)

Topic 1: Cells biology 1.1 Introduction to cells

Understandings and Applications U: According to the cell theory, living organisms are composed of cells U: Organisms consisting of only one cell carry out all functions of life in that cell A: Questioning the cell theory using atypical examples A: Investigation of functions of life in Paramecium and one name photosynthetic unicellular organism

1.1 Introduction to cells Cell Theory: 1.All organisms are made up of one or more cells 2.Cells are the smallest units of life 3.All cells come from pre-existing cells dia/commons/b/b1/Optical_micros cope_nikon_alphaphot_%2B.jpg

Exceptions to the cell theory! Muscle cells (Myocytes) um3.jpg content/uploads/2014/04/Forms-of-hyphae-Septate-and- Coenocytic-Hyphae.jpg Fungal hyphae/Aseptate fungi Giant Algae: up to 100mm in size but only contains one nucleus!

The functions of life Paramecium They also divide!divide Metabolism Growth Reproduction Response Homeostasis Nutrition

FunctionParameciumChlamydomonas NutritionEndocytosisPhotosynthetic GrowthFood (organic molecules + minerals) Photosynthesis and absorption of minerals ResponseReacts to stimuli ExcretionExpels waste MetabolismEnzymes catalyse chemical reactions HomeostasisMaintains internal environment within limits ReproductionAsexual/sexual nzeller/03_Protozoen/IMAGES/ PARAMECIUM_BURSARIA_ A.JPG Molnar/Krieger_Chlamydomonas165.jpg The functions of life in unicellular organisms

How do we know the sizes of these organisms? The largest to smallest: Cell >> organelles >> bacteria>>virus>>membranes>>molecules

How do we calculate magnification? Magnification = image size actual size I M A Problem: What is the magnification if the actual size of the amoeba is 800μm? *Make sure all measurements are in the SAME units

What is the scale bar? Magnification = image size actual size I M A Problem: What is the magnification if the actual size of the amoeba is 800μm?

Practice problems Complete and SHOW ALL WORK in section A of handout: 1.The width of a human hair is 0.1mm. What is the width in micrometers? 2.The diameter of the drawing of the an amoeba is 100mm. The actual diameter of the amoeba is 100 micrometers. What is the magnification of the drawing? 3.E. coli has a diameter of 10 micrometers. The drawing is 200cm. What is the power of magnification? 4.A drawing of a virus has a length of 35 millimeters. The actual length is 1 nanometer. What is the magnification of the drawing? 5.The width of the plasma membrane of a cell is 9nm. In the drawing, it is 15mm. What is the magnification?

How do we use a scale bar? Measure the length of scale bar. In this example, it is 1cm = 3.33μm What is the magnification of the human cheek cell? 1cm = 10mm 3.33μm = mm Magnification = 10mm/0.0033mm = 3003x The magnification of the human cheek cell is 3003x

Practice problems Complete section B of handout