Because they are prokaryotic cells.
Answer:
Because most natural environments harbor a stunningly diverse collection of microbial species. Within these communities, bacteria compete with their neighbors for space and resources. Laboratory experiments with pure and mixed cultures have revealed many active mechanisms by which bacteria can impair or kill other microbes. Additionally, a growing body of theoretical and experimental population studies indicate that the interactions within and between bacterial species can profoundly impact the outcome of competition in nature. The next challenge is to integrate the findings of these laboratory and theoretical studies, and to evaluate the predictions they generate in more natural settings.
Explanation:
The correct answer is A.
According to the principle of superposition the youngest rock formed lies at the upper layer and the oldest rock are found at the lowest of all the layers. The principle of superposition states that the layer of rock that is formed first lies at the bottom and the layer that is formed upper after that lies at the upper and is the newest layer of rock.
Many things can occur such as an increase in temperature.Which would then result in greater/destructive natural disasters. Temperature would cause either droughts or floods in certain places as well.