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Book A

Chapter 2

Viruses and Bacteria

1. Virus -- a small non-living particles that invade

and then reproduce inside a living cell (like a parasite)

The norwalk virus is sometimes responsible for outbreaks of the stomach flu.
This is an influenza virus.
Some viruses are rod -shaped such as this tobacco mosaic virus. Cold virus
HIV virus
Hepatitus virus
Herpes virus

2. Bacteria

-- unicellular

--no cell nucleus

--some reproduce by binary fission in which one cell divides to form two new cells.The new cells had one parent cell, therefore this is asexual reproduction.The genetic material of the new cells is identical to the genetic material of the parent cell.
Bacteria reproducing by binary fission (dividing).
-- some reproduce by conjugation where one bacteria

passes some of its genetic material to

another bacteria. The second bacteria then

divides by binary fission. The new bacteria

contains genetic material from the second parent as well as the original

bacteria, therefore this is sexual reproduction.

Binary fission of a bacteria
Proteus mirabilis bacteria

magnified 17,650 times
Spirilla bacteria
Streptococci bacteria

Book A

Chapter 3

Protists and Fungi

1. Protists

-- one celled plant-like or animal-like organisms

-- reproduce by binary fission (asexual)

or conjugation (sexual)

amoeba

stentor

blepharsima

paramecium

2. Fungi

-- most are multicellular

-- absorb dead or decaying organisms

Reproduction:

- yeast cells (unicellular fungi) use budding
- other fungi produce spores which are usually from

one parent (asexual reproduction) but may

occasionally have two parents (sexual reproduction)
Spores being released from a fungi