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?
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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
http://upload.wikimedia.org/wikipe
dia/commons/b/b1/Optical_micros
cope_nikon_alphaphot_%2B.jpg
Exceptions to the cell theory!
http://scvp.net/acr/images/gr
um3.jpg
Muscle cells
(Myocytes)
Giant Algae: up to 100mm in size
but only contains one nucleus!
http://www.medical-labs.net/wpcontent/uploads/2014/04/Forms-of-hyphae-Septate-andCoenocytic-Hyphae.jpg
Fungal
hyphae/Aseptate
fungi
The functions of life
Paramecium
They also divide!
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Metabolism
Growth
Reproduction
Response
Homeostasis
Nutrition
The
functions of
life in
unicellular
organisms
http://www.mikrowelt.info/02_Ei
nzeller/03_Protozoen/IMAGES/
PARAMECIUM_BURSARIA_2010
05A.JPG
https://wiki.umn.edu/pub/IBS8102/030410Molnar/Krieger_Chlamydomonas165.jpg
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
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
I
actual size
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 = 0.0033mm
Magnification = 10mm/0.0033mm
= 3003x
The magnification of the human cheek
cell is 3003x
Practice problems
• Complete section B of handout