Question

The rapidly increase in growth after showing initial period is called (a) Log phase (b) Leg phase (c) Both (a) and (b) (d) None of these

Short answer

The answer is (a) Log phase

Step-by-step solution

Identify the correct term

In biology, the phase of rapid, exponential population growth in a bacterial population is called as the log phase, also called the exponential phase or logarithmic phase. This is when the cells are actively dividing and their number doubles every generation time.

Match the term with the corresponding option

Looking at the options given in the question, option (a) 'Log phase' perfectly aligns with the definition we know for the term that satisfies the description given.

Key concepts

Log Phase

In the world of microbiology, the "log phase" (short for logarithmic phase) is a fascinating period during bacterial growth. During this phase, bacteria are happily multiplying at maximum speed, given their environment is suitable and nutrients plenty.
During the log phase, bacterial cells are in ideal conditions for growth. This means there's enough food and the right temperatures, which allows them to divide rapidly. Each bacterial cell doubles in a consistent manner known as exponential growth.

• Division Rate: This is by far the fastest rate of bacterial division during the life cycle. It's in this smooth and accelerated phase that biologists often study cells.
• Nutrient Utilization: The available nutrients are consumed swiftly as the cell numbers increase.

However, this vigorous growth cannot go on forever. The speed of growth during the log phase often results in an eventual lack of resources, communicating that the environment will soon reach a limit for supporting such rapid growth.

Exponential Phase

The exponential phase is indeed another name for the log phase! It represents a critical moment in bacterial life. In this phase, the number of individual bacteria doubles at a constant time interval, showcasing exponential growth.
What makes this phase exciting is the math behind it. These bacterial populations grow so fast that we often need to express their numbers in terms of exponents. That's why it's called the exponential phase.

• Doubling Time: This is the time taken for the population to double. It's a fixed period that often depends on the type of bacteria and environmental conditions.
• Basic Calculations: If you start with one bacterium, after one doubling time, you will have two. After another, there will be four, then eight, and so on.

This phase is particularly important in scientific research and industrial applications, where understanding and harnessing rapid bacterial growth is crucial.

Bacterial Growth

Bacterial growth is a multi-phase process in which bacteria multiply and expand in number. This process isn't just limited to the log or exponential phase. Instead, it's part of a broader growth curve, which typically includes several distinct phases.

• Lag Phase: This is where bacteria are adjusting to their environment before growth really kicks off. It's a sort of preparation phase.
• Log (Exponential) Phase: The phase of rapid doubling discussed earlier, where conditions are perfect for growth.
• Stationary Phase: Growth stalls as resources become limited, and waste products develop. There might even be a balance where growth equals death of cells.
• Death Phase: Eventually, without change, the environment becomes unsustainable for growth, and bacterial numbers decrease.

Understanding bacterial growth in all its phases gives us insight into how bacterial populations behave in different environments. It aids in everything from developing antibiotics to understanding ecosystems. This knowledge is vital for both public health and scientific advancement.