A controlled experiment is when the experimenter can change one variable in the experiment and completely change the results.
Redi experiment involved a closed jar with rotting meat on the inside. He waited for a few days and found no new forms of life in the jar.
He then did the same experiment, but this time he took the lid off the jar. After those few days he found there were maggots in the rotting meat from flies.
This is a great example of a controlled experiment, because he only had to change one variable to completely change the results. In this case that variable was just removing the lid from the jar.
Redi was trying to prove spontaneous generation with his experiment. Although, it failed.
Spontaneous generation: When life forms from non-livings.
Redi disproved spontaneous generation, but proved biogenesis.
Biogenesis: When life comes from other living beings.
He proved biogenesis because the flies had reproduced when the jar was opened.
Without concentration you can't have diffusion, because diffusion is basically the spreading out of molecules which are concentrated, or compacted.
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection. The theory of evolution is based on the idea that all species? are related and gradually change over time.
Hello!
While they do not penetrate very far into the body, they can indeed get through.
Commonly, materials that emit alpha, beta or gamma radiation get into the body alone or with other materials which have may become contaminated.
Here are some ways these could get in:
Through breathing; It could be in the air or mixed with dust, which is in the air.
Drinking; It disolves in water, meaning the material could get in your body without you knowing.
In the soil; If soil is contaminated, and plants grow in that soil, you will get a small ammount of alpha and beta particles.
Lastly, animals; Plants and animals can become contaminated, the particles coud be taken in through consumtion.
Hope this helps!
Have a great day!
