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