1 Study Guide Questions And 100%
Correct Answers 2025-2026 Updated.
Agar - Answer a gel-like polysaccharide compound used for culturing microbes; SEAWEED
Biofilms are - Answer where most microbes live in these polysaccharide-encased
communities. it may enhance bioremediation efforts and protect organisms against harmful
chemicals
pure culture - Answer All the bacterial cells that result from the replication
of a single original bacterial organism
colony - Answer a single microbial cell, that has multiplied on the solid medium in a limited
area..?
Method for isolating bacteria - Answer the STREAK PLATE METHOD is the simplest and most
commonly used method ISOLATING BACTERIA
How are Bacterial cultures
stored? - Answer 4 degrees celcius? freeze drying..?
Explain the stages of Bacterial growth curve and characteristics of these stages: - Answer LAG
PHASE: begin synthesizing enzymes required for growth-metabolically active cells
EXPONENTIAL (LOG) PHASE: the number of bacteria is rapidly inc
STATIONARY PHASE:
total numbers remain constant, others grow and become much more resistant to drugs
DEATH PHASE: total number of viable cells decline
, types of bacterial groups based
on temperature, pH and oxygen
preference - Answer Psychrophiles, Psychrotrophs, Mesophiles, Thermophiles,
Hyperthermophiles
Proteins of thermophiles - Answer resist denaturing
Human pathogens
prefer which temperature range? - Answer 35- 40 celcius
Optimum pH for most bacteria - Answer pH of 7
The enzymes that deal with toxic oxygen-containing molecules is/are - Answer superoxide
dismutase and catalase
How does an aerobic organism protect itself from the action of Reactive Oxygen Species (ROS) -
Answer superoxide dismutase and catalase..?
Chemotrophs obtain energy from - Answer oxidation of chemical compounds
heterotrophs - Answer uses (Glucose) organic carbon as their source
autotrophs - Answer uses (CO2) inorganic carbon as their source
Blood agar as differential medium - Answer contain a substance that microbes
change in an identifiable way
Selective MacConkey Agar - Answer allows only gram negative bacteria to grow & contain bile
salts and crystal violet that inhibit growth of Gram- positive bacteria.
Differential MacConkey Agar - Answer differentiates Gram negative bacteria based on their
ability to ferment lactose.