Question

Duration of a cell cycle in yeast is approximately (a) 90 seconds (b) 90 minutes (c) 20 minutes (d) 45 minutes

Short answer

The typical duration of a cell cycle in yeast is approximately 90 minutes, so the appropriate choice is (b) 90 minutes.

Step-by-step solution

Recall the Function and Duration of a Cell Cycle

A cell cycle is an ordered set of events, resulting in cell growth and division into two daughter cells. In yeast (Saccharomyces cerevisiae), which is a unicellular organism, the average cell cycle duration is established through experimental results and it's longer than the shortest proposed options. So option (a) and (c) can be eliminated.

Deciding between the Remaining Options

Between options (b) and (d), the correct answer should be the one that is commonly referenced as the average duration of cell cycle in yeast. Checking relevant biology resources will support in making the right choice.

Arriving at the Correct Answer

Given their short lifespan and how quickly they reproduce, a typical cell cycle in yeast is commonly referenced as approximately 90 minutes. So, the correct answer is (b) 90 minutes.

Key concepts

Cell Cycle

The cell cycle is a crucial concept to understand when studying cellular biology, particularly in yeasts like Saccharomyces cerevisiae. It consists of a series of events that a cell goes through as it grows and divides. In simple terms, the cell cycle is divided into two main phases: interphase and mitosis (or M phase).

During interphase, the cell grows and duplicates its DNA, preparing for division. This phase includes three stages known as G1 (gap 1), S (synthesis), where the DNA replication occurs, and G2 (gap 2), where the cell continues to grow and prepares for mitosis. Next is the mitotic phase, which involves the segregation of duplicated chromosomes and eventually leads to cell division, known as cytokinesis.

The duration of the cell cycle can greatly vary among organisms and even among different cells of the same organism. Factors influencing the length of the cell cycle include the type of cell, availability of nutrients, and environmental conditions. While mammalian cells might have a cell cycle length ranging from 20 to 24 hours, yeast cells, which are much simpler in structure and function, have a significantly shorter cell cycle.

Yeast Reproduction

Yeast reproduction is fascinating because it can occur asexually through a process known as budding, which is remarkably different from the cell division in multicellular organisms. In budding, a small bud forms on the parent yeast cell, which grows and eventually separates to become a new individual cell.

When conditions are favorable, particularly when there are ample nutrients and a suitable environment, yeast cells can reproduce rapidly. This rapid reproduction is beneficial in many commercial and scientific applications. For example, brewers and bakers harness the power of yeast to ferment sugars, producing alcohol and causing bread to rise, respectively.

Understanding the frequency of yeast reproduction is crucial, especially in industries that rely on yeast's fermentative abilities. By knowing the average duration of the cell cycle in Saccharomyces cerevisiae, scientists and manufacturers can optimize conditions to maximize production efficiency without compromising the quality of the yeast cells.

Saccharomyces Cerevisiae

Saccharomyces cerevisiae is a species of yeast that is widely studied and used not only because of its importance in food and beverage production but also as a model organism in scientific research. The popularity of S. cerevisiae in research stems from its relatively simple genetic structure, the ease of genetic manipulation, and its rapid growth rate.

Moreover, S. cerevisiae plays a pivotal role in genetics, molecular biology, and cellular biology because many of its cellular processes are similar to those in higher eukaryotes, making it an ideal candidate for studying fundamental biological mechanisms.

The thorough research on S. cerevisiae has made it feasible to determine the average cell cycle duration under controlled conditions, which, as the exercise reveals, is approximately 90 minutes. This knowledge is indispensable in laboratory settings where precision in experimentation timings is key to success in research and development.