IB induction        HL Physio Option Nerves & Muscles
SL Core Topics         Resp. & Photosyn.
Cells & Organelles         Plant Science
Biochemistry       .                                                            HL Genetics
Ecology                                                                              Human Reprod.
Genetics         Nucleic Acids
Health & Physiology         Excretion
Neurobiology   Experiments  

  ISTScience

 Immune System
Two basic cell architectures: prokaryotes & eukaryotes

prokaryote and eukaryote organization
  1. Prokaryotes
    • "pro" = before, + "karyos" = nucleus
    • Includes bacteria and cyanobacteria (formerly called blue-green algae and thought to be plants), as well as archaea (see below)
    • Simple architecture not understood until EM technology in 1940's
    • Sample electron micrographs
    • Typical sizes: 0.5-5 µm (micrometer) diameter
  2. Eukaryotes
    • "eu" = true, + "karyos" = nucleus
    • Typically contain membrane-bounded organelles (e.g. mitochondria, lysosomes, endoplasmic reticulum, Golgi bodies)
    • Typical sizes: anywhere from 5 micrometers (yeast cells) to 50 or 100 micrometers. A few cells (such as bird eggs) are enormous, and some cells (such as animal nerve cells) can attain lengths of many meters, even though small in diameter.
    • Includes protists, fungi, animals and plants