Answer:
hope this helps some
Explanation:
The theory that explains how this could have happened is called endosymbiotic theory. An endosymbiont is one organism that lives inside of another one. All eukaryotic cells, like your own, are creatures that are made up of the parts of other creatures. Mitochondria, the important energy generators of our cells, evolved from free-living cells.
Answer:
Chemicals that are secreted from antigen-presenting cells then activate helper T cells.
Explanation:
Answer:
The movement pushes food and liquid through your GI tract and mixes the contents within each organ. The muscle behind the food contracts and squeezes the food forward, while the muscle in front of the food relaxes to allow the food to move. The digestive process starts when you put food in your mouth.
Answer:
do you know what the choices are?
