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%)
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
http://upload.wikimedia.org/wikipedia/commons/b/b1/Optical_microscope_nikon_alphaphot_%2B.jpg
Exceptions to the cell theory!
Muscle cells (Myocytes)
http://scvp.net/acr/images/grum3.jpg
http://www.medical-labs.net/wp-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!
• Metabolism• Growth• Reproduction• Response• Homeostasis• Nutrition
Function Paramecium Chlamydomonas
Nutrition Endocytosis Photosynthetic
Growth Food (organic molecules + minerals)
Photosynthesis and absorption of minerals
Response Reacts to stimuli Reacts to stimuli
Excretion Expels waste Expels waste
Metabolism Enzymes catalyse chemical reactions
Homeostasis Maintains internal environment within limits
Reproduction Asexual/sexual
http://www.mikrowelt.info/02_Einzeller/03_Protozoen/IMAGES/PARAMECIUM_BURSARIA_201005A.JPG
https://wiki.umn.edu/pub/IBS8102/030410-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 sizeI
M A
Problem: What is the magnification if the actual size of the amoeba is 800 m?μ
*Make sure all measurements are in the SAME units
What is the scale bar?
Magnification = image sizeactual size
I
M A
Problem: What is the magnification if the actual size of the amoeba is 800 m?μ
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 =
3.33 mμ
What is the magnification of the human cheek cell?1cm = 10mm3.33 m = 0.0033mmμ
Magnification = 10mm/0.0033mm= 3003x
The magnification of the human cheek cell is 3003x