When an E. coli cell is infected by multiple phages, what route of infection (lytic or lysogenic) will the phages take? Why? Choose one: O A. either lytic or lysogenic because environmental conditions (such as nutrient levels) play a more important role in determining the type of infection O B. neither lytic nor lysogenic because an E. colicell cannot be infected by more than one phage at a time O C. lytic because the multiple phages in the E. colicell need to move from an area of high concentration inside the cell to infect other cells O D. lysogenic because infection by multiple phages suggests a high concentration of phages in the environment and increased competition for cells to infect

The correct option is 'A'

When E.coli is infected by multiple phages,they will take either lytic or lysogenic pathway.

Explanation:

The decision between lysogeny and lytic growth hinges on a delicate balance between the race of two regulatory genes that are C₁ ans Cro viz lambda repressor protein and Cro protein.

If C₁ gene manages to produce enouth repressor which binds or block Operators and turning off all early transcription including transcription Cro genes. That causes Lysogeny.

On the other hand, Cro gene codes for Cro protein which blocks  operators and turning off C₁ genes transcription. This causes Lytic infection.

The winner of the race between C₁ and Cro is determined by the concentration of the gene product which is determined by cellular protease concentration. The CII concentration leads to lysogeny.

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.