It is likely that the light blue colonies have a mutation in GENE I (lacI gene). LacI (lactose inhibitor) is a DNA-binding factor that represses transcription of the lac operon.
The lacI gene (regulatory gene for lac operon) is a gene located upstream of the three genes of the lac operon (i.e., lacZ, lacY, and lacA), which are transcribed as a unit.
The inducer of the lac operon is allolactose. When lactose is present, a small amount of this molecule is converted to allolactose.
The lac repressor, which is encoded by the lacI gene, binds to the operator upstream of the lac operon, thereby preventing its transcription unless the inducer is present.
Finally, the lacZ gene produces an enzyme called β-galactosidase, while X-gal is a blue-colored product precipitated when a bacterial colony expresses a functional β-galactosidase.
Learn more in:
brainly.com/question/9739412
Answer:
The correct answer is option A. "The contents of blood come into closer contact with tissues in a closed system than an open system".
Explanation:
In a closed circulatory system, the blood has an specific path, circulating from arteries to veins and to smaller blood vessels throughout the body. This is in contrast with open circulatory systems at which the blood is not contained in arteries or veins but it suffuses the body. A closed circulatory system have many advantages over open circulatory system, however in a closed circulatory system the contents of blood are not into closer contact with tissues in than an open system. Actually, in an open circulatory system the blood is in closer contact with tissues.
Below are the choices:
(1) a nucleus
<span>(2) a chromosome </span>
<span>(3) a protein molecule </span>
<span>(4) an enzyme molecule
</span>
In the nucleus. However since chromosomes are in the Nucleus they contain the <span>DNA a cell needs to survive. This is why it is in the Nucleus.
</span>
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
Answer:
d. A purine base forms hydrogen bonds to pair with a pyrimidine base located on the opposite DNA strand. Specifically, A pairs with T, and C pairs with G.
Explanation:
