AraC protein certain to the ara
operator works as a repressor that avoid transcription of the same ara operon
and the araC gene AraC protein is an activator in the presence of arabinose and
repressor in the absence of arabinose -With arabinose absent, the AraC protein
stays as
a homodimer. One AraC protein put together to the ara initiator and the other
protein now binds to a different regulatory site in DNA called the ara operator.
Mantle
In mollusks with shells, the outer cells of the mantle secrete
calcium carbonate and conchiolin to form the shell. The mantle is the body wall
of a mollusk. It resides below the shell where it covers the body of the
animal.
The material that makes up the membrane cell is the phospholipids, cholesterol, proteins, and carbohydrates.
Answer:
<u><em>PROPHASE</em></u>
Explanation:
The first stage in Meiosis I is prophase I. During this stage the DNA condenses into chromosomes. During prophase I, homologous chromosomes pair up and exchange sections of DNA. This is called recombination or crossing over