1.1.1 Discuss the theory that living organisms are composed of cells. Note: Skeletal muscle and some fungal hyphae are not divided into cells but have a multinucleate (many nuclei) cytoplasm. Some biologists consider unicellular organisms to be acellular. 1.1.2 State that a virus is a non-cellular structure consisting of DNA or RNA surrounded by a protein coat. 1.1.3 State that all cells are formed from other cells. This is the ‘Cell theory’.

1.1.4 Explain 3 advantages of using a light microscope Answer: see things in color, large field of view, easily prepare sample material, portable, could possibly see a living thing or a moving thing. 1.1.5 Outline the advantages of using electron microscopes. Higher resolution (you can see the difference between two things at a smaller distance.)Higher magnification.

1.1.6 Define organelle. An organelle is a discrete structure within a cell, and has a specific function. 1.1.7 Compare the relative sizes of molecules, cell membrane thickness, viruses, bacteria, organelles and cells, using appropriate SI units. molecules (1 nm), thickness of membranes (10 nm), viruses (100 nm), bacteria (1 μm), organelles (up to 10 μm), most cells (up to 100 μm). The three-dimensional nature/shape of cells should be emphasized.

1. 1. 8 Calculate linear magnification of drawings 1.1.8 Calculate linear magnification of drawings. Drawings should show cells and cell ultrastructure with scale bars eg. Magnification should also be stated, eg × 250. Cell lab: 10 different specimens on 100 or 430 power. of the 10specimens, 3 of them (at least) need to be fresh slides –there will be onion etc… on Monday. Each specimen gets 5 points: BIG Drawing of 2 or 3 cells (only) with 3 things labeled = 3 points Magnification labeled Scale bar that tells the size of the cells.

1.1.9 Explain the importance of the surface area to volume ratio as a factor limiting cell size. The cell has to exchange materials with the environment. Surface area is the area in direct contact with the environment. Surface area doesn’t grow as quickly as volume when the cell gets bigger. For a 1 cm cube the SA:Vol = 6:1 For a 10 cm cube the SA:Vol = 0.6:1 SO! Cells can’t be too big, or they don’t get the nutrients from the environment!!! 1.1.10 State that unicellular organisms carry out all functions of life.

1.1.11 explain that cells in multicellular organisms differentiate to carry out specialized functions by expressing some of their genes but not others. Every cell has all of the body’s DNA… but only some of it is activated. Differentiation: When a cell is specialized to be one type of cell like a nerve cell or muscle cell. 1.1.12 Define tissue, organ and organ system tissue: group of similar cells performing a particular task (blood cells, epithelial,muscle tissue… note that one cell doing a task is meaningless.) Organ: structural unit made of a group of tissues which work together to perform a function (liver, heart) Organ system: several organs working together (digestive, circulatory)

1.2.1 Draw a generalized prokaryotic cell as seen in electron micrographs. These guys use mesosomes for cell division… the inner membrane forms a curl…

1.2.2 State one function for each of the following: Cell wall: made of amino sugars, protection and strength Slime capsule: protection from drying out, makes cells stick to stuff and other cells Membranes: control of what comes in and out Cytoplasm: contains ribosomes, DNA, Mesosome: curl of membrane that makes the capsule and moves DNA in cell division

Quiz and Notebook check Friday 1.1.1 to 1.2.2