cells : principles and applications of science 

• cell membrane - controls what moves in and out of the cell
• mitochondria - where aerobic respiration takes place
• cytoplasm - where most of the chemical reactions take place
• nucleus - contains genetic information
• nuclear membrane - movement of particles in and out of the cell
• starch grains - stores starch

Microscopes : history

• first names in 1609
• first cells observed in 1665 which were cork plant cells (dead)
• first living cells observed around 1674 - 1683 (living cells)
• nucleus first observed in 1831
• universal cell theory 1839
• evidence for new cells generated from existing cells in 1892

how compound light microscopes work

• it has two lens,objective and eyepiece

• the objective lens is placed closed to the specimen

• the eyepiece is the lens through which specimen is viewed

• both lens magnify the same

• calculations

  eye piece = x10 or x20

  objective lens = x4,x10,x40,x100

  %%[formula = eye piece x objective]%% ⭐

• a transition light microscope forms an image from the light passing through the specimen

• specimen must be thin

• magnification

• %%[magnification = measured size of the image / actual size of the object]%%⭐

Characters of living things

• growth
• reproduction
• releases energy
• nutrition
• excretion
• sensitivity
• movement
• made up of cells

principles of living organisms

• cells and tissues

• types of tissues

• structures found within cells

• function of structures found within cells

• difference between type of cell

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