Answer:
Antibiotic resistance can evolved in bacterial population in the following ways:
Explanation:
- In response to constant exposure to antibiotics some members of a bacterial population develop some beneficial mutations in some essential genes that gives them survival advantage in terms of food and space over the sensitive bacterial strains and hence they are capable of out-competing the sensitive bacteria.
- This happens due to the process of Natural Selection.
- These genes are called antibiotic resistance genes and bacteria usually carry them on plasmids in form of cassettes where genes resistant to multiple drugs are incorporated. These plasmids are called the MDR or Multi-Drug Resistance Plasmids.
- These resistant plasmids can be easily transferred among bacterial populations by conjugation, transformation or transduction or direct plasmid transfer.
- The resistant genes encode for proteins that render the drug ineffective by promoting their efflux from the cells, preventing their entry into the cell, chemically modifying them such that they become non-functional or altering the target site of the drug.
Answer:
The populations are isolated and thus do not interbreed.
Explanation:
Answer:
El sistema nervioso consiste en el cerebro, la médula espinal, los órganos sensoriales y todos los nervios que conectan estos órganos con el resto del cuerpo. Juntos, estos órganos son responsables del control del cuerpo y la comunicación entre sus partes.
Answer: the bloodtype of Jesse is A Rhesus D positive
Explanation:
Antigens at present on the blood cells while antibodies are present in the serum. Thus, to prevent agglutination which occurs if the red blood cell antigen is similar to the antibody, the red blood cell of Jesse which has the B antigen will have the A antibodies produced. Thus, since the red blood cell determines the bloodtype of a person, Jesse therefore has the B bloodtype.
