Chapter 19, Problem 10STP

Summary Introduction

To analyze : 

The structures that help a typical bacterium to survive in a drastic and ever-changing environment.

Introduction :

Bacteria are some of the most primitive forms of life. Being the earliest forms, they are adapted to all types of habitat. They are ubiquitous and present wherever organic matter is present and can be supported, such as ocean bottoms, deep-sea thermal vents, hot springs, below icebergs, inside or outside the body of other organisms, deserts, etc. Even thousands of bacteria are present in the air we breathe. 

Explanation of Solution

Bacterial chromosome incorporates changes in terms of nucleotide sequences necessary to survive in the changing environment. These adaptations are transferred from generation to generation. 

They divide exponentially and transfer the genes for resistance through horizontal gene transfer. Pili helps in the formation of a conjugation tube through which the genes for resistance are transferred. The daughter cells thus become resistant to many antibiotic agents and can survive in the presence of such chemicals. 

The capsule of the bacterial cell protects it against desiccation and harsh environment. Capsule prevents phagocytosis of the bacterial cell by a phagocyte. It also protects the cell from antibacterial agents present in the environment. 

Cell walls retain the structure of a bacterial cell and prevent it from bursting or shrinkage if the surrounding environment is hypotonic or hypertonic, respectively.

Flagella help these bacterial cells to locomote. With the help of flagella, bacterial cells can move towards the regions of higher oxygen concentration, light source, and organic matter. 

Plasma membrane enables selective movement of the substances across the cell. It allows nutrients to move inwards while all the toxic substances to move outwards. It serves as a barrier and seperates the cytoplasm from outer environment.

Conclusion

Thus, we can conclude that a bacterial cell has all the required structures which can help it to survive in extreme environments. It can adapt to the changing environment more rapidly due to lesser complexity.