<span>Centrosomes are made of from arrangement of two barrel-shaped clusters of microtubules, called “centrioles,” and a complex of proteins that help additional microtubules to form.</span>
Answer:bebop and the other
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Explanation:
The double membrane. It's theorized that chloroplasts used to be their own single-celled organism in the environment (and therefore with its own membrane). Then, the theory states, a larger cell took in the chloroplast by endocytosis, which involves surrounding the chloroplast in the large cell's own membrane. The chloroplast would then have two membranes surrounding it. This is similar to the thinking for mitochondria becoming an organelle as well. Hope this helps! :)
There are lots:
Biology and Medicine - cloning and expression of human insulin in bacteria (stopped having to produce it from pig pancreases); Watson & Crick discovery of the structure of DNA; gene therapy in humans
Chemistry - determination of the exact number of molecules in a mole (Avagadro's number); discovery of radioactivity (Rutherford); the invention of nylon (DuPont); Boyle's law (behavior of gases)
I'll help you with your science