Question 21

Not all bacteria have negative effects and cause infections.

Many bacteria play essential roles in various ecosystems and human health, including digestion and nutrient absorption. While some bacteria are pathogenic and can lead to infections, the majority are harmless or even beneficial.

A) TRUE

This statement is incorrect because it generalizes all bacteria as harmful. While some bacteria do cause diseases, many others are crucial for processes such as decomposition, nitrogen fixation, and maintaining gut health.

B) FALSE

This option is correct, as it accurately reflects the fact that not all bacteria are harmful. Many bacteria are beneficial and necessary for various biological functions, contradicting the notion that all bacteria cause infections.

C) Sometimes

This choice is misleading because it implies that bacteria can be harmful only under certain conditions, which does not encompass the full spectrum of bacteria's roles. While some bacteria can cause infections in specific scenarios, many are consistently beneficial.

D) Not sure

This option indicates uncertainty and does not provide any factual information regarding the nature of bacteria. A clear understanding is necessary, as it is well-documented that not all bacteria are detrimental.

Conclusion

The assertion that not all bacteria have negative effects is supported by the existence of numerous beneficial bacteria that contribute to health and ecological balance. Option B effectively clarifies this reality, while the other options either misrepresent the facts or fail to provide a definitive understanding of bacteria's roles. Thus, only option B accurately captures the complexity of bacterial functions.