The variable that is changed/controlled in a scientific experiment .
Answer: If we kill all the organisms in one trophic level, then transfer of energy as well as matter to next higher level will stop. It will lead to over- population at one particular level causing amongst the individuals. This would seriously disturb the food chain and can cause the collapse of an ecosystem even.
If we do we can find the weak points in cancer contaminated cells
Answer:
He examined covered and uncovered meat to determine that maggots came from eggs.
Explanation:
Prior to Redi's experiment and other supporting experiments, it was formerly believed that life could emanate from non-living things, for example, the generation of maggots from rotting meat.
In 1668, a scientist called Francesco Redi disproved the idea of spontaneous generation. He did this when he experimented that the maggots from meats are only as a result of eggs laid by flies when they perched on the meat.
He placed the meat in two jars; an uncovered jar and another in a covered jar with a cloth, after several days, the uncovered jar had maggots on the meat, while the covered jar had no maggot on the meat, but on the cloth. With this experiment, he was able to demonstrate that the maggot arose from the eggs of the flies, not the meat itself which is nonliving and hence, disproved the idea of spontaneous generation.
