Answer:
He proposed that all cells come from existing cells.
Explanation:
He proposed that all cells come from existing cells, completing the cell theory.
I believe the answer is A. The R group gives amino acid unique characteristics. Hope this helps :)
Answer:
Top 10 Inventions That Changed the World
The compass. ...
The printing press. ...
The internal combustion engine. ...
The telephone. ...
The light bulb. ...
Penicillin. (Image credit: National Institutes of Health) ...
Contraceptives. (Image credit: Public domain) ...
The Internet. (Image credit: Creative Commons | The Opte Project)
I think is is a small limited population
<span>The lac operon has three genes that encode for proteins that break down lactose into galactose and glucose. When there is no lactose around, it wouldn't make sense for the prokaryote to make these proteins as it would be a waste of energy. So, when there is no lasctose around, the lac repressor binds the operator region of the operon, which inhibits RNA polymerase's ability to bind and start gene expression. However, when lactose is available, it binds to the lac repressor and deactivates it via allosteric inhibition. Once the lac repressor is gone, the genes can be transcribed into mRNA which can be translated into proteins which can go and break down the lactose. </span>
