Portage Biod 171 module 4 (2025) Actual Exam
Questions and Answers A+ Graded
1. T/F: .differential .media .is .best .suited .for .distinguishing .between .2 .bacteria-
: .true
2. a .researcher .is .asked .to .determine .which .vial .contains .e. .coli .and .which
.contains .salmonella. .which .media .is .best?: .differential .media
3. what .are .the .requirements .of .a .fastidious .microbe?: .A .fastidious .microbe .is
.an .organism .with .complex .growth .requirements .such .that .if .absent .it .will .not .grow.
.Enriched .medias .thus .contain .these .specific .and .essential .nutrients .required .for .the
.growth .of .a .particular .subset .of .microorganisms.
4. alpha .hemolysis .activity: .no .change
5. beta .hemolysis .activity: .greenish-brown .color
6. gamma .hemolysis .activity: .distinct .zone .of .clearing
7. plating: .the .process .of .spreading .a .bacterial .culture .onto .a .petri .dish .filled .with
.agar
8. best .agar .media .for .growing .staph: .manitol .salt
9. in .EMB .agar, .what .color .indicates .the .presence .of .e. .coli?: .metallic .green
10. In .an .attempt .to .detect .the .presence .of .the .pathogenic .strain .of .E. .coli
.O157:H7, .a .researcher .spread .a .culture .onto .a .MacConkey .agar .with .failed
.results. .What .type .of .agar .should .they .(correctly) .try .next? .Why?: .it .should .be
.plated .on .sorbitol .macConkey .agar, .it .is .formulated .to .detect .pathogenic .e. .coli .it .has
.sorbitol .instead .of .lactose .and .pathogenic .e. .coli .can .ferment .there- .non .pathogenic
e. .coli, .can .ferment .on .both
11. would .a .gram .stain .be .necessary .to .confirm .if .e. .coli .was .gram .positive .or
.negative?: .No, .because .only .gram .negative .microbes .will .grow .on .a .macconkey
.agar
12. T/F: .Chocolate .agar .gets .its .brown .color .from .cocoa .to .produce .an .en-
.riched .media: .false
13. columbia .cna .agar .is .used .to .isolate:: .gram .positive .media
14. Blood .agar .is .what .type .of .media?: .enriched .and .differential
15. The .polysaccharide .based .hardening .agent .added .to .LB .media .to .produce
Questions and Answers A+ Graded
1. T/F: .differential .media .is .best .suited .for .distinguishing .between .2 .bacteria-
: .true
2. a .researcher .is .asked .to .determine .which .vial .contains .e. .coli .and .which
.contains .salmonella. .which .media .is .best?: .differential .media
3. what .are .the .requirements .of .a .fastidious .microbe?: .A .fastidious .microbe .is
.an .organism .with .complex .growth .requirements .such .that .if .absent .it .will .not .grow.
.Enriched .medias .thus .contain .these .specific .and .essential .nutrients .required .for .the
.growth .of .a .particular .subset .of .microorganisms.
4. alpha .hemolysis .activity: .no .change
5. beta .hemolysis .activity: .greenish-brown .color
6. gamma .hemolysis .activity: .distinct .zone .of .clearing
7. plating: .the .process .of .spreading .a .bacterial .culture .onto .a .petri .dish .filled .with
.agar
8. best .agar .media .for .growing .staph: .manitol .salt
9. in .EMB .agar, .what .color .indicates .the .presence .of .e. .coli?: .metallic .green
10. In .an .attempt .to .detect .the .presence .of .the .pathogenic .strain .of .E. .coli
.O157:H7, .a .researcher .spread .a .culture .onto .a .MacConkey .agar .with .failed
.results. .What .type .of .agar .should .they .(correctly) .try .next? .Why?: .it .should .be
.plated .on .sorbitol .macConkey .agar, .it .is .formulated .to .detect .pathogenic .e. .coli .it .has
.sorbitol .instead .of .lactose .and .pathogenic .e. .coli .can .ferment .there- .non .pathogenic
e. .coli, .can .ferment .on .both
11. would .a .gram .stain .be .necessary .to .confirm .if .e. .coli .was .gram .positive .or
.negative?: .No, .because .only .gram .negative .microbes .will .grow .on .a .macconkey
.agar
12. T/F: .Chocolate .agar .gets .its .brown .color .from .cocoa .to .produce .an .en-
.riched .media: .false
13. columbia .cna .agar .is .used .to .isolate:: .gram .positive .media
14. Blood .agar .is .what .type .of .media?: .enriched .and .differential
15. The .polysaccharide .based .hardening .agent .added .to .LB .media .to .produce
