Introduction:
Fungi and bacteria are both types of microorganisms that are able to withstand much greater changes in their surrounding medium compared to animal cells. This is due to several factors that enable them to adapt and survive in diverse environments.

Cell Wall:
- Fungi and bacteria possess a cell wall which provides them with structural support and protection.
- The cell walls of fungi are composed of chitin, a tough and flexible polysaccharide, while bacterial cell walls can be made of peptidoglycan or other substances.
- These cell walls act as a barrier against external changes, such as osmotic pressure and fluctuations in temperature.

Membrane Transporters:
- Fungi and bacteria have specialized membrane transporters that regulate the movement of molecules in and out of their cells.
- These transporters can actively pump out toxic substances or take up essential nutrients, allowing them to survive in environments with varying concentrations of chemicals.

Spore Formation:
- Fungi and some bacteria have the ability to form spores, which are highly resistant structures that can withstand harsh conditions.
- Spores are produced in response to unfavorable environmental changes and can remain dormant for long periods.
- When conditions become favorable again, the spores can germinate and give rise to new cells.

Metabolic Flexibility:
- Fungi and bacteria have diverse metabolic capabilities, allowing them to use a wide range of energy sources.
- They can adapt their metabolism to utilize different nutrients present in their environment, such as sugars, proteins, and even pollutants.
- This metabolic flexibility enables them to survive in environments where animal cells would struggle to obtain sufficient energy.

Genetic Adaptability:
- Fungi and bacteria have the ability to undergo genetic mutations and horizontal gene transfer, allowing them to rapidly adapt to new environments.
- Horizontal gene transfer involves the transfer of genetic material between different individuals or species, leading to the acquisition of new genes and traits.
- This genetic adaptability gives fungi and bacteria an advantage in surviving and thriving in changing environmental conditions.

Conclusion:
Overall, fungi and bacteria are able to withstand much greater changes in their surrounding medium compared to animal cells due to their cell walls, membrane transporters, spore formation, metabolic flexibility, and genetic adaptability. These adaptations allow them to survive in diverse and challenging environments, making them highly resilient microorganisms.