Gram (+)


Gram (-)






Microscopic life covers nearly every square centimeter of Earth. The smallest and most common microorganisms are 1)________________ , single-celled organisms that lack a nucleus. For many years, most prokaryotes were simply called bacteria. 2)_________________ are single-celled organisms that lack a nucleus. Bacteria can be identified by their shapes, the chemical nature of their cell walls, and the way they move. There are three different types of shapes. 3)________________ are spiral and corkscrew-shaped bacteria. 4)_______________ are spherical shaped and 5)_________________ are rod-shaped bacteria. These three shaped attach in two different ways. A cluster of bacteria is termed 6)______________________. A long linear chain of bacteria is termed 7)_________________________. Bacteria can also be identified by cell wall. A Gram stain, a purple and red stain, is used to determine the type of cell wall present. 8)______________ bacteria stain bluish-purple and indicates a single cell wall. 9)__________________ bacteria stain reddish-pink and indicate a double cell wall. Bacteria commonly have a 10)______________, a whiplike tail structure to propel them forward.

Conjugation (2x)

Genetic diversity



Binary fission



Bacteria reproduce two ways. 11)_________________ is an asexual form of reproduction where the DNA is replicated and the bacterial cell splits into two. Another form of reproduction involves sharing of genetic material. This exchange of genetic information is called 12)____________________. During 13)_________________, a hollow 14)______________ forms between two cells and genes move from one cell to the other. This transfer of genetic information increases the 15)_________________________ in populations of bacteria. When growth conditions become unfavorable, many bacteria form structures called 16)____________________. It is formed when a bacterium produces a thick internal wall that encloses its 17)______ and a portion of its cytoplasm. This tough form of bacteria can be destroyed through 18)__________________, using extreme heat or chemicals



Lytic cycle

Nucleic acids

Protein capsid






Viruses are particles of 19)______________ that is enclosed in a 20)_________________. Viruses are 21)_______________ because it does not carry out any life characteristics. A virus’s purpose is to infect other organisms. Viruses that only infect bacteria are called 22)________________________. Viruses infect its hosts two ways. The 23)______________ infection is when the virus enters the cell, makes copies of itself, and causes the cell to burst. This form is very aggressive. The first step in this cycle is 24)___________, when the bacteriophage attaches to the bacterial host cell. The second step is 25)___________. The third step is 26)___________ where the bacteriophage’s proteins and nucleic acids are synthesized. The fourth step is 27)_________________. In the last step, the host bacterial cell bursts open releasing the newly made viruses. The bursting of the host cell is called 28)__________.



Lytic cycle

Lysogenic cycle

The other method of infection is called 29)___________________. This form of infection is much more passive. In this method, the virus embeds its 30)________ into the DNA of the host cell and is replicated along with the host cell’s DNA. The host cell may not know it is infected until the virus switches over to the aggressive 31)________________ and causes symptoms of illness.