1-4

Question 1

what is a colony or colonies?

Answer 1

group or clusters of million of cells of the same species

Question 2

what are a colony forming units (CFUs)

Answer 2

some colonies form from individual cells and others from pairs

Question 3

how does one incubate a streak plate?

Answer 3

inverted position
37 degrees Celsius
48 hours

Question 4

where should one see isolated colonies in a streak plate?

Answer 4

4th quadrant

Question 5

what is a mixed culture?

Answer 5

microbial culture consisting of two or more species

Question 6

what is a pure culture?

Answer 6

microbial culture consisting of a single species

Question 7

what is a commonly used isolation technique?

Answer 7

streak plate/ streaking

Question 8

what happens during streaking?

Answer 8

cell density decreases

leading to individual cells being deposited separately on the agar surface

Question 9

when is a quadrant streak/ T streak used?

Answer 9

samples with high density

Question 10

when is a zigzag/ continuous streak used?

Answer 10

samples with lower cell density

Question 11

what are two ways a person can streak a plate to avoid contamination?

Answer 11

1. leave agar plate on table and lift lid (using as a shield)
2. place lid of plate down on table and hold it in the air at an angle