SERIES MICROBIOLOGY LAB EXAM 1 COMPLETE QUESTIONS AND CORRECT ANSWERS | GRADED AND THE LATEST SERIES

2025-2026 SERIES
MICROBIOLOGY LAB EXAM 1 COMPLETE QUESTIONS
AND CORRECT ANSWERS | GRADED AND THE
LATEST SERIES
What is the purpose of a streak plate?


Ans: 1) 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


Question: What is a colony?


Ans: Areas of growth that arise from a single cell.


Question: How do colonies form?


Ans: They are formed by spreading out cells. Cells are spread and reproduce
over and over again through bionary fission until visable mass of cells appear.


Question: What is a pure culture?


Ans: Culture containing only one type of organism


Question: What kind of media are colonies able to form on?


Ans: agar slant, broth media, agar plate


Question: When is a agar slant used? Pros & cons


Ans: 1) 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

, 2025-2026 SERIES
Question: What are the 4 criteria for labeling a microbial culture?


Ans: 1) initials or name AND group number
2) date
3) growth media type
4) culture name or source of inoculum


Question: Describe bacillus (bacilli) morphology


Ans: rod shaped cells, longer than wide, sausage like, can use rod or bacillus


Question: describe coccus morphology


Ans: cells are ball shaped or spherical


Question: Describe coccobacillus morphology


Ans: elongated spheres- not quite spherical, but not clearly a rod. Tends to occur
in species which are normally rod-shaped during rapid growth.


Question: Describe spirillum morphology


Ans: Helical, loose or tight coils. Look like wavy lines - morphology has no
arrangement


Question: Describe filamentous morphology


Ans: Long elongated cells. Look like a tangled mass of branched filaments- no
arrangement

, 2025-2026 SERIES
Question: Describe vibrio morphology


Ans: A curved rod or comma shape


Question: What does No arrangement mean?


Ans: Single cells, ungrouped. Not all cells have an arrangement


Question: What is the cell arrangement Diplococci/Diplobacilli


Ans: Pairs of cells. Diplococci are pairs of cocci, diplobacilli are pairs of rods


Question: What is the cell arrangement Streptococci/Streptobacilli?


Ans: Chains of cells. Streptococci are chains of cocci, streptobacilli are chains of
rods


Question: What is the call arrangement staphylococcus?


Ans: Irregular clusters of cells- like bunches of grapes.


Question: What is the cell arrangement of tetrads?


Ans: Sets of 4 regularly arranged cells


Question: What is the cell arrangement of palisade?


Ans: Bacilli (usually 2-4 cells) arranged side by side. Columns or "V-forms"


Question: What genus is an acid fast bacteria?