Practice - Microbiology

Front

What is the preferred temperature range for mesophiles?

Back

Mesophiles prefer temperatures around 20-45°C, with an optimal growth temperature of approximately 37°C, which is close to human body temperature.

Front

Define the four stages of microbial growth.

Back

The four stages of microbial growth are: 1. Lag phase - adaptation to the environment; 2. Log (exponential) phase - rapid cell division; 3. Stationary phase - growth rate slows as resources are depleted; 4. Death phase - decline in the number of viable cells.

Front

What type of organisms are psychrophiles?

Back

Psychrophiles are organisms that thrive in cold environments, typically at temperatures below 15°C.

Front

What are thermophiles?

Back

Thermophiles are microorganisms that grow optimally at high temperatures, usually between 45°C and 80°C.

Front

What is the significance of pH in microbial growth?

Back

pH affects enzyme activity and nutrient availability; most microbes prefer a neutral pH (around 7), but some thrive in acidic or alkaline conditions.

Front

What is the role of atmospheric gases in microbial growth?

Back

Different microbes require different atmospheric gases; for example, aerobes need oxygen, while anaerobes are inhibited or killed by oxygen.

Front

What is an antibiotic?

Back

An antibiotic is a substance that inhibits the growth of or kills bacteria, used in the treatment of bacterial infections.

Front

How can the effectiveness of an antibiotic be measured?

Back

The effectiveness of an antibiotic can be measured by observing the zone of inhibition around the antibiotic disk on an agar plate.

Front

What does the term 'colony morphology' refer to?

Back

Colony morphology refers to the characteristics of bacterial colonies, including shape, size, color, and texture.

Front

What is the difference between a circular and irregular bacterial colony?

Back

A circular colony has a smooth, round shape, while an irregular colony has uneven, jagged edges.