Preliminary Biology Notes of All Topics
Year 11 Preliminary Biology |
Full Syllabus Dot Point Notes |
Patterns in Nature, the Local Ecosystem, Life on Earth & Evolution of the Australian Biota |
Patterns in Nature
- Organisms are made up of cells that have similar structural characteristics
- Outline the historical development of the cell theory, in particular the contributions of Robert Hooke and Robert Brown
- The cell theory:
- All living things are composed of cells
- The cell is the smallest unit of life
- All living cells arise from pre-existing cells
- Historical development:
- 1485 - Leonardo da Vinci used glass lens to study small objects
- 1626 - Francesco Redi conducted experiment which disproved spontaneous generation thus proving ‘all living cells arise from pre-existing cells’
- 1665 – Robert Hooke observed cork cells using a compound microscope and described ‘little boxes or cells distinct from one another’
- 1676 - Anton von Leeuwenhoek described unicellular organisms - bacteria - in pond water (animalcules)
- 1831 - Robert Brown observed the nucleus in plant and animal cells
- 1839 - Schleiden and Schwann formulated the cell theory that ‘cells are a small unit of life and ‘all living things are made up of cells’
- 1858 - Virchow stated: ‘where a cell exists, there must have been a pre-existing cell, just as the animal only arises from an animals and the plant only from a plant.’
- 1933 - Max Knoll and Ernst Ruska developed the transmission electron microscope
- 1965 - Cambridge Instruments produced first scanning microscope
- Describe the evidence to support the cell theory
- All living things are composed of cells: Leeuwenhoek discovered unicellular organisms
- Cells are the smallest unit of life: Hooke discovered that the cork is made up of cells
- All living cells arise from pre-existing cells: Virchow observed cells dividing, disproving spontaneous generation
- Discuss the significance of the technological advances to the development of the cell theory
- Invention and further development of the microscope: Robert Hooke’s development of the compound microscope enabled him to see the basic structure of cells
- Improvements were made to lenses- increased resolving power and allowed more detailed observations of the cell structure.
- Robert Brown’s later development of a single lens microscope was used to identify the cell nucleus.
- Ernst Ruska built the first electron microscope in 1933, which allowed a more detailed observation of all cell structures = organelles
- Identify cell organelles seen with current light and electron microscope
Light Microscope | Electron Microscope |
Nucleus | Nucleus |
Nucleolus | Nucleolus |
Vacuoles | Vacuoles |
Chloroplast | Chloroplast |
Cell Wall | Cell Wall |
Mitochondria | Mitochondria |
Golgi Body | |
Cell Membrane | |
Endoplasmic Reticulum (smooth and rough) | |
Lysosomes (mostly animals, rare in plants) | |
Ribosomes | |
Peroxisomes |
- Describe the relationship between the structure of cell organelles and their function
Organelle | Structure | Function |
Mitochondria | Smooth outer membrane, highly folded inner membrane (structure called matrix, edges called cristae) | Site of respiration and creation of ATP for cell energy |
Chloroplasts | Plastids containing pigments e.g. chlorophyll stored in internal membrane stacks | Site of photosynthesis in green plants |
Golgi Body/Apparatus | Flattened membrane bound sacs | Store and secrete important biochemical e.g. proteins and lysosomes |
Lysosomes | Membrane bound spheres or ovals with lipid bilayer | Contain digestive enzymes to digest unwanted material within the cell |
Smooth and Rough Endoplasmic Reticulum (ER) | Membrane bound channels, where some are smooth (do not consist of ribosomes attached to the outside) and some rough (has ribosomes attached to it) | Rough ER collects polypeptides and amino acids from the cytosol and assembles proteins for transportation. Smooth ER manufactures lipids and sometimes continues it metabolism process |
Ribosomes | Small spherical bodies either moving freely or connected to rough endoplasmic reticulum | Site of protein synthesis |
Nucleus | Membrane bound sphere containing DNA, chromosomes and in some cases RNA | Control centre of cell |
Cell Membrane | Flexible semi-permeable membrane – hydrophilic heads and hydrophobic tails consisting of proteins and lipids with a phospholipid bilayer | Selective transport of substances in and out of cell |
Cell Wall | Rigid external coating around the cell membrane made of cellulose (plants) or other material e.g. Silica, chitin, etc. | Supports and strengthens cell |