1. Biology Tuesday, October 9 Reminders: Check my website for notes and to find out what you missed whenever you’re absent. You can also read the lesson plans and homework assignments. Week’s outline T- notes & Lab W- Bacteria Lab & test corrections Th- Bacteria Lab & Cell collage project F- Bacteria Lab & Cell Lab

2. - All Bacteria are prokaryotes. That is, they are single-celled organisms that do not have a nucleus. - Bacteria can be identified by their shapes, the chemicals in their cell walls, and the ways they obtain energy.

3. SHAPES OF BACTERIA Bacilli: are rod-shaped bacteria. Cocci: are spherical bacteria. Spirilla: are spiral-shaped bacteria.

4. HOW BACTERIA OBTAIN ENERGY Some bacteria are autotrophs: they make their own food by a process similar to photosynthesis. Most bacteria are heterotrophs: they obtain energy from organic molecules (protein, lipids, and carbohydrates)and then break them down like humans do.

5. GROWTH and REPRODUCTION of BACTERIA Under favorable conditions, prokaryotes such as bacteria can grow and divide very quickly. Some bacteria can divide (double in number) every 20 minutes. Favorable conditions include warm temperatures, pH 7, and moist environments. Examples: Bacteria can reproduce by binary fission, or conjugation

6. Growth & Repro. continued Binary Fission - results in two identical “daughter cells” having the same genetic material. Conjugation - results in the offspring bacteria having new combinations of genetic information. NOTE: Bacteria do NOT need a host cell to divide.

7. WHAT IS A VIRUS? A virus is very tiny. (much smaller than a bacteria) A virus consists of particles of DNA or RNA (nucleic acids)surrounded by a protein coat, and sometimes lipids. - A virus can reproduce ONLY BY INFECTING OTHER CELLS, and using that host cell’s nucleus to replicate viral DNA or RNA. A VIRUS NEEDS ANOTHER LIVING CELL IN ORDER TO PRODUCE MORE VIRUSES. Sometimes this kills the host cell.

8. WHAT IS A VIRUS? continued A virus undergoes a lytic cycle, whereby a virus enters a cell, makes copies of itself, and causes the cell to burst. (See Bio book p. 481, Fig. 19-10 for the Lytic Cyle of a virus.)

9. VIRUSES Viruses come in many different shapes (see p. 479 in Biology book) A virus needs a Host cell in order to replicate new genetic material and make more viruses.

10. IS A VIRUS ALIVE OR NOT ALIVE? A virus is not really a cell. It is simpler than the smallest cells. Most biologists do not consider a virus a living thing because: a.) the virus is not a cell. b.) a virus needs another cell in order to reproduce its genetic material and protein coat. c.) A virus can evolve quite quickly, changing its DNA or RNA and changing the markers on its protein coat so that host cells do not recognize the virus as a “foreign” particle until after the virus has entered the host cell.

11. Bacteria Lab Tuesday, Oct. 9 – 16 First page says “Bacteria Culturing Journal” Please number all pages now. Read pages 2-4 (3-5 minutes). Clarification of Instructions 1 2 3 4