MB 302 Oregon State Exam 2 (lectures
9-17) Questions with Correct Verified
Answers 2025-2026 Updated.
Eukaryotes Reproductive Strategy - Answer Asexual and sexual
Bacteria and Archea Reproductive Strategy - Answer Asexual (budding, multiple fission,
spores)
Binary fission steps - Answer 1. Cell elongation
2. Chromosome replication and separation
3. Septum formation
4. Cell division
Growth in multicellular orgamisms - Answer Size of organism
Growth in bacteria - Answer Observation of pop
1. Increase in # of cells or mass
2. Average number of cells
Growth Curve - Answer Observed in batch culture
Plotted as log of cell # vs time
Growth Curve step 1 - Answer Lag phase
No cell division
Producing more enzymes, atp, ribosomes, etc
Time depends on conditions
-young cells: brief
-old cells: longer
-damaged cells: longer still
-nutrient rich to poor: longest
,Cells most sensitive to adverse conditions
Generation time - Answer How long it takes pop to double
Varies for different organisms under optimal conditions
GT=#original X 2^#of generations
Growth curve step 3 - Answer Stationary Phase
Bacteria= 10^9 cells/ml
Pop remains constant
Death=division
Starvation response
-starvation proteins
-DPS covers DNA
-chaperone proteins: prevent denature
Growth curve step 4 - Answer Senesence and death
# of viable cells fall exponentially
Two hypothesis
1. Viable but noncultureable
-temporarily dormant
2. Programmed cell death
-some commit suicide to save others
Halophiles - Answer Salt lovers
require >0.2 M NaCl
accumulate and require K
Extreme Halophiles - Answer require 2-2.6 M NaCl
Halotolerant - Answer can withstand large changes in NaCl
, Neutrophiles - Answer grow at neutral pH (5.5-8.0)
most microbes
inside of cells must be neutral
changes in pH - Answer disrupt membranes
denature enzymes
Acidophiles - Answer grow at low pH (0-5.5)
maintain net outward translocation of proteins
-unique membrane proteins
-proton removal during respiration
Alkalophiles - Answer grow at high pH (8-11.5)
-maintain net inward translocation of protons
-coordinated H+ and Na+ fluxes
Low temperatures - Answer no enzyme function
membranes solidify
cells need more unsaturated fats in membrane
High temperatures - Answer needed to grow at high temp
-specific enzyme
-dna protection
-more fatty acids in membrane
Psychrophile - Answer 0-20 C. opt=15 C
Psychrotroph - Answer 0-36 C. opt=22 C
Mesophile - Answer 15-45 C. opt=37 C
9-17) Questions with Correct Verified
Answers 2025-2026 Updated.
Eukaryotes Reproductive Strategy - Answer Asexual and sexual
Bacteria and Archea Reproductive Strategy - Answer Asexual (budding, multiple fission,
spores)
Binary fission steps - Answer 1. Cell elongation
2. Chromosome replication and separation
3. Septum formation
4. Cell division
Growth in multicellular orgamisms - Answer Size of organism
Growth in bacteria - Answer Observation of pop
1. Increase in # of cells or mass
2. Average number of cells
Growth Curve - Answer Observed in batch culture
Plotted as log of cell # vs time
Growth Curve step 1 - Answer Lag phase
No cell division
Producing more enzymes, atp, ribosomes, etc
Time depends on conditions
-young cells: brief
-old cells: longer
-damaged cells: longer still
-nutrient rich to poor: longest
,Cells most sensitive to adverse conditions
Generation time - Answer How long it takes pop to double
Varies for different organisms under optimal conditions
GT=#original X 2^#of generations
Growth curve step 3 - Answer Stationary Phase
Bacteria= 10^9 cells/ml
Pop remains constant
Death=division
Starvation response
-starvation proteins
-DPS covers DNA
-chaperone proteins: prevent denature
Growth curve step 4 - Answer Senesence and death
# of viable cells fall exponentially
Two hypothesis
1. Viable but noncultureable
-temporarily dormant
2. Programmed cell death
-some commit suicide to save others
Halophiles - Answer Salt lovers
require >0.2 M NaCl
accumulate and require K
Extreme Halophiles - Answer require 2-2.6 M NaCl
Halotolerant - Answer can withstand large changes in NaCl
, Neutrophiles - Answer grow at neutral pH (5.5-8.0)
most microbes
inside of cells must be neutral
changes in pH - Answer disrupt membranes
denature enzymes
Acidophiles - Answer grow at low pH (0-5.5)
maintain net outward translocation of proteins
-unique membrane proteins
-proton removal during respiration
Alkalophiles - Answer grow at high pH (8-11.5)
-maintain net inward translocation of protons
-coordinated H+ and Na+ fluxes
Low temperatures - Answer no enzyme function
membranes solidify
cells need more unsaturated fats in membrane
High temperatures - Answer needed to grow at high temp
-specific enzyme
-dna protection
-more fatty acids in membrane
Psychrophile - Answer 0-20 C. opt=15 C
Psychrotroph - Answer 0-36 C. opt=22 C
Mesophile - Answer 15-45 C. opt=37 C
