Bacteria have different phage resistance mechanisms, such as spontaneous mutations, the CRISPR-Cas system.
Spontaneous mutations are the main mechanisms leading to phage resistance by altering the structure of bacterial wall components that act as phage receptors. These include lipopolysaccharides (LPS), outer membrane proteins, cell wall teichoic acids, capsules, and other bacterial components.
Answer:
1. Nucleoid
2. Plasmid
Explanation:
Prokaryotes are groups of organisms characterized by the lack of a membrane-bound nucleus in their cell. Due to this, the genetic material (DNA) of prokaryotes are found naked i.e. not housed. The DNA of a prokaryote is arranged in a single coiled chromosome located in a region of the cell called NUCLEOID.
However, some prokaryotes e.g. bacteria carry genes on extrachromosomal pieces of circular DNA called PLASMID. Plasmids carry certain genes like antibiotic resistance genes.
The OECD found that the responsiveness of housing supply to demand in the UK was the weakest among developed countries, due in large part to green belt policies. The green belt concept was first introduced for London in 1938 before the 1947 Town and Country Planning Act enabled local authorities to designate the status themselves. The policy was introduced to contain urban sprawl following huge post-war housing developments, and expanded greatly between 1951 and 1964. Since 1979, the green belt has doubled to cover 13 per cent of land in England (while only 2.3 per cent is covered by buildings).
Autoinducer molecules are signalling molecules that need bacteria. In order for the autoinducer molecules to signal, the bacteria must find a way to initiate the signal and a way to respond to the signal it had created. Autoinducer molecules increase in production as the density of the bacteria cell increases.
The main difference between prokaryotes and eukaryotes is the presence of nucleus in eukaryotes and its absence in prokaryotes. Also, prokaryotes are unicellular, so one cell is a whole organism. On the other hand, eukaryotes are mainly multicellular, and thus more complex. More complex DNA is inside the nucleus in the eukaryotes which enables them to conduct a wider range of functions. Prokaryotes, as a single cell, have simple functions present.
