PERFORMANCE OBJECTIVES FOR LAB 1

A bacillus or rod is a hotdog-shaped bacterium having one of the following arrangements

A bacillus or rod is a _______________bacterium

They usually appear spherical and have a diameter of 3 - 5 µm. Yeasts commonly reproduce asexually by a process called budding. Unlike bacteria, which are prokaryotic, yeasts are eukaryotic.

Describe the appearance of a typical yeast. Shape Diameter Reproduce Pro or Euk

Yeast is 10 um cocci are approximately 0.5 - 1.0 micrometer (µm)

Differentiate a yeast from a coccus-shaped bacterium by its size.

Division in one plane produces either diplococcus: 2. streptococcus: b. Division in two planes tetrad sarcina d. Division in random planes produces a staphylococcus arrangement staphylococcus

State and describe five different arrangements of cocci

bacillus: streptobacillus: coccobacillus:

State and describe three different arrangements of bacilli.

vibrio b. spirillum: c. spirochete:

State and describe three different spiral forms.

coccus bacillus spiral

State three basic shapes of bacteria.

The approximate size of a microorganism can be determined using an ocular micrometer (see Fig. 5) , an eyepiece that contains a scale that will appear superimposed upon the focused specimen.

When given an oil immersion microscope, a prepared slide of a microorganism, and an ocular micrometer, determine the size of that organism in micrometers.

a single bacillus

bacillus

oval and similar to a coccus

coccobacillus

a pair of cocci

diplococcus:

a thick, rigid spiral

spirillum:

a thin, flexible spiral

spirochete

bacilli in chains

streptobacillus

a chain of cocci

streptococcus

an incomplete spiral or comma-shaped

vibrio

a cube of 8 cocci

sarcina

The ocular micrometers provided are calibrated so that when using 1000X oil immersion microscopy, the distance between any two lines on the scale represents a length of approximately one micrometer.

The ocular micrometers provided are calibrated so that when using 1000X oil immersion microscopy, the distance between any two lines on the scale represents a length of approximately ___________ micrometer.

cocci in irregular, often grape-like clusters

staphylococcus

a square of 4 cocci

tetrad