Microbiology Lab Exam 1| 125 Questions With Accurate Answers Correct 100%

What is the purpose of a streak plate? - ANSWERS1) To separate cells so that they grow to form isolated colonies 2) To confirm if a culture is a pure colony or mixed 3) To confirm is there is contamination in your culture What is a colony? - ANSWERSAreas of growth that arise from a single cell. How do colonies form? - ANSWERSThey are formed by spreading out cells. Cells are spread and reproduce over and over again through bionary fission until visable mass of cells appear. What is a pure culture? - ANSWERSCulture containing only one type of organism What kind of media are colonies able to form on? - ANSWERSagar slant, broth media, agar plate When is a agar slant used? Pros & cons - ANSWERS1) Smaller amount of surface area prevents the media from drying out too quickly 2) useful for medium term storage 3) viable for a couple of months if stored properly What are the 4 criteria for labeling a microbial culture? - ANSWERS1) initials or name AND group number 2) date 3) growth media type 4) culture name or source of inoculum Describe bacillus (bacilli) morphology - ANSWERSrod shaped cells, longer than wide, sausage like, can use rod or bacillus describe coccus morphology - ANSWERScells are ball shaped or spherical Describe coccobacillus morphology - ANSWERSelongated spheres- not quite spherical, but not clearly a rod. Tends to occur in species which are normally rod-shaped during rapid growth. Describe spirillum morphology - ANSWERSHelical, loose or tight coils. Look like wavy lines - morphology has no arrangement Describe filamentous morphology - ANSWERSLong elongated cells. Look like a tangled mass of branched filaments- no arrangement