Answer:
Krill
Explanation:
Based on the information provided within the question it can be said that the the Crabeater Seal's main source of food are Krill. These are a type of shrimp that can be found in cold water such as Antarctica. Despite the misleading name Crabeater Seal' do not eat crabs seeing as since the are no crabs in Antartica.
Explanation:
The lac operon
When lactose is present, bacteria need the enzymes to break it down. But if no lactose is present, bacteria do not need to waste resources making enzymes to break down a sugar that isn't there. Like a switch, the operon is turned on when the enzymes are needed.
The right answer is A.) DNA in mitochondria
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Eukaryotic cells, with their many intracellular organelles, have long been considered progeny of prokaryotes that would have become more complex as a result of genetic mutations. But from the 1960s, biologist Lynn Margulis proposed an alternative explanation that was first received coldly by the scientific community. His endosymbiotic theory, proposed in a more formal way in a 1981 book, proposes that eukaryotic cells as we know them today would be the result of a series of symbiotic associations with different prokaryotes.
Mitochondria and chloroplasts also have their own DNA that is not trapped in a nucleus, which is also the case with prokaryotes. However, the proteins encoded by this DNA do not cover all mitochondrial proteins. The prokaryote is thought to have lost some genes to the nucleus of the cell, a process known as "endosymbiotic gene transfer". For this reason, mitochondria and chloroplasts are now host-dependent for the synthesis of most of their components.