Answer:
The correct answer is option (D) "His- strain grows on an his- plate".
Explanation:
The Ames test is a procedure that allows to detect if a given compound can cause mutations on a tested organism by growing strains of bacteria that require histidine (His-) to growth, since they are not able to produce its own histidine. In the Ames test, the bacteria is exposed to a given compound and is grown in a medium with small amount of histidine (his- plate). If the His- strain grows on a his- plate, it means that the bacteria has mutated to synthesize its own histidine and it is considered as a positive result on a the Ames test.
Answer:
B. The membrane lets certain substances move across it freely, while others must move through a “gate”.
Explanation:
Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.
Defects in transcription factors underlie some forms of cancer.
Answer:
When a bullet strikes, a characteristic ‘keyhole’ is formed—a defect that is circular at one end with tangential fractures radiating outwards in parallel, allowing the bone between them to lever out. So, in other words a major surgery is needed to get the bullet out. It is very risky as well
Explanation:
Answer:
I am not certain but I think carbohydrate
