B is the correct answer because none of this that you put are testable.
<span>Penicillium notatum is a fungi.
</span>Penicillium<span> is a genus of ascomycetous fungi which has a major importance in the natural environmen. It plays an important role in food and drug production as well. Some members of the said genus produce penicillin, a molecule that is used as an antibiotic. These antibiotics kill or stop the growth of certain </span>kinds<span> of bacteria inside the body.</span>
The correct answer is: B) continuous transcription of the structural gene controlled by that regulator
A regulatory gene is gene that encodes for a protein, such as a repressor (or activators) that controls the transcription of another gene or group of genes.
The regulatory gene of a repressible operon encodes for the repressor that inhibits gene transcription. So, when that repressor isn’t active, transcription occurs continuously.
Answer:
False
Explanation:
A double-helical DNA molecule consists of two DNA strands. A DNA strand has free 5' phosphate at one end and a free hydroxyl group (OH) at its 3' end. A DNA double helix is said to be antiparallel since each end of the double helix has an exposed 5' phosphate on one strand and a free 3' hydroxyl group (OH) on the other. This means that the two DNA strands run in opposite directions. A phosphate group is always esterified to the 5' carbon of the pentose sugar; never at its 3' end.
Answer:
Letter C
Explanation:
Salmon have a physiological adaptation that allows osmoregulation to occur in two different environments (seawater and freshwater). There are specific molecules in the salmon gills that "pump" and "remove" Na and Cl ions. When at sea these molecules pump the ions out of the salmon's body and into freshwater, the same molecules remove Na and Cl from the water bringing it into the animal's blood.