Ib Biology Sl Topic 2 Revision Notes

Only available on StudyMode
  • Download(s) : 781
  • Published : July 21, 2012
Open Document
Text Preview
* Topic 2: Cells
* 2.1 Cell theory
* 2.1.1
* Outline Cell Theory
1. All living organism are composed of cells
2. Cells come from pre-existing cells
3. Cells are the smallest unit of life
*
* 2.1.2
* Discuss the reasons for cell theory
1. When organism are looked at under a microscope, they are consistently made up of cells 2. Cells carry out asexual reproduction – called Mitosis 3. Cells are the smallest unit of organisms that can carry out all process of life *

* 2.1.3
* State Unicellular organisms can carry out all functions of life * G – Growth = size and volume increase
* H - Homeostasis = Maintenance of internal cell conditions * M – Metabolism = chemical reactions e.g. respiration
* N – Nutrition = synthesis of organic materials
* R – Reproduction = asexual (cell division)
* R – Response = to change (environmental)
*
* 2.1.4
* Compare relative sizes
* 1 nm = molecule
* 10nm = Membrane
* 100nm = Virus
* 1 um = Bacteria
* 10um (or less) = organelle
* 100um (or less) = cell
*
* 2.1.5
* Calculating Linear Magnification (answer = magnification) 1. Measure scale bar on page e.g. 15mm
2. Convert answer into same units on scale bar e.g. 15mm = 15000um (as 1000um = 1 mm) 3. Divide answer by number on scale bar e.g. 15000um / 5um = 3000 * Magnification is 3000x

* If magnification given (answer = actual size)
1. Measure object given e.g. 41mm
2. Divide answer by Magnification e.g. 41mm/750 = 0.055mm 3. Convert to sensible unit 0.055 x 1000 = 55um
*
* 2.1.6
* Explain the importance of Surface area to volume ratio * Mathematical rule- as an object increases in volume, the ratio of its total surface area to its volume decreases, i.e. the larger an object, the smaller its surface-volume ratio. The rate of metabolism of a cell is a function of its mass/volume, whereas the rate of exchange of materials and energy (heat) is a function of its surface area. If the volume gets too big, the surface area can’t absorb enough gases/food to penetrate to the center. *

* 2.1.7
* State Multi-cellular organisms show emergent properties * Emergent properties arise from the interaction of the component parts: the whole is greater than the sum of the parts *
* 2.1.8
* Explain Multi-cellular organisms
* Cells under differentiation, becoming specialized – expressing only a fraction of their genes becoming more efficient *
* 2.1.9
* State Stem Cells
* Adult stem cells retain their capacity to differentiate *
* 2.1.10
* Outline Therapeutic use
* Bone marrow Transplants = Stem cells found in bone marrow give rise to plattlets, red and white blood cells. Therefore these cells can be used to treat people with certain types of cancer e.g. Hodgkin’s Lymphoma *

*
*
*
*
*
*
* 2.2 Prokaryotic Cells
* 2.2.1
* Draw and label diagram
*
*
*
*
*
*
*
*
*
*
*
*
*
*
* 2.2.2
* Annotate Functions
* Cell wall = Protection
* Plasma membrane = controls transfer of substances
* Cytoplasm = site of metabolic reactions
* Ribosomes = Protein synthesis
* Nucleoid = contains naked DNA
* Pili = adheres cell to surface
* Flagella = used for movement
*
* 2.2.3
* Identify structures from 2.2.1 in electron microscope
*
* 2.2.4
* State that Prokaryotic cells divide by Binary Fission
*
*
*
*
* 2.3 Eukaryotic Cell
* 2.3.1
* Draw and label diagram
*
*
*
*
*
*
*
*
*
*
*
* 2.3.2
* Annotate Functions
* Golgi apparatus = modifies proteins
* Mitochondria = aerobic respiration
* Lysosome = contains Digestive enzymes
* Ribosome = protein...
tracking img