Answer:
<u>Biofilms are</u> defined as complex communities of microorganisms that grow embedded in a self-produced polymeric organic matrix and adhered to a living or inert surface, and that can present a single microbial species or a range of different species
Explanation:
The bacteria that form the biofilm are in what is called sessile form, exhibiting a phenotype different from those of the same cells in unicellular or free form (planktonic form) with respect to the growth rate and gene transcription (Donlan, 2002 ).
<u>
The formation</u> of biofilms is an adaptive strategy of microorganisms, since growth in biofilm offers four important advantages: (I) protects microorganisms from the action of adverse agents, (II) increases the availability of nutrients for their growth, (III) facilitates the use of water, reducing the possibility of dehydration and (IV) enables the transfer of genetic material (DNA). All of these circumstances can increase your survival capabilities. As a consequence, <u>the usual methods of disinfection or the use of antibiotics are often ineffective against biofilm bacteria</u>.
In addition to the risk of contamination, the development of biofilms can interfere with different processes and cause damage to the equipment. In drinking water systems the formation of biofilms can obstruct the pipes reducing their speed and transport capacity causing an increase in energy consumption. The formation of biofilm in heat exchangers and cooling towers can reduce heat transfer and as a consequence its efficiency in the process. The formation of persistent biofilms on metal surfaces can cause corrosion due to acid production by bacteria.
The rigth answer is the picture 4.
In the case of a hypotonic extracellular medium, there will be a large inflow of water to dilute the Na, thereby increasing the cell volume and there will be an explosion of the membrane in places so hemolysis, the contents of the red cell ( Hemoglobin) is released into the blood plasma.
On the other hand, in the case where the extracellular medium is hypertonic, therefore archi concentrated, well it will be the water of the red cell that will come out without damaging the membrane, we will rather have a red cell that is completely flat and non-functional without release. erythrocyte (Hb) content.
