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.
Answer:
See the answer below
Explanation:
Person X is feeling a burning sensation in several muscles<u> because of the accumulation of lactic acid due to inadequate oxygen in their system.</u> When oxygen becomes inadequate during exercises, anaerobic respiration takes place to augment the oxygen shortage and this leads to the production of lactic acid which accumulates up in the muscles and gives a burning sensation.

Person Y does not feel any burning sensation in their muscles <u>because oxygen is adequate in their system and they do not need to respire anaerobically.</u> <em>Person X exercise regime must have been more rigorous than that of person Y.</em>
Answer:
Getting fit, C, changes them in terms of self-esteem and confidence
Explanation:
Theres more to doing exercising than just getting a healthier body. It could also contribute to your positive body image.
Answer:
Energy enters the ecosystem via sunlight as solar energy
Explanation:
when the solor energy comes down it goes to the grass when the animals eat it they have consumed that i put a picture below if that helps