Answer:
The endosymbiotic theory states that some of the organelles in eukaryotic cells were once prokaryotic microbes.
I would say landslide because it does cause because of the lost of friction.
Check out this website http://science.jrank.org/pages/3421/Hummingbirds-Biology-hummingbirds.html
Here is your answer I hope it was useful: a striation is any of a number of tiny parallel grooves such as: the scratches left by a glacier on rocks or the streaks or ridges in muscle tissue. Your answer is yes, there are striation across the width of a muscle.
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