Answer:
DNA may be taken up by bacterial cells and be active.
Explanation:
To understand Avery, MacLeod, and McCarty's experiment, it is important to know Frederick Griffith's precursor experiment. The microbiologist worked at the British Ministry of Health's Pathology Laboratory with pneumococci (commonly known as the bacterium Streptococcus pneumoniae, then known as Pneumococcus, which causes pneumonia), which were previously classified into several types. When cultured in petri dishes in the laboratory, the pneumococci that synthesize their capsules generate 'smooth' colonies. Subcutaneous injection of liquid culture of these pneumococci into mice causes their death. However, in vitro culture also allows the emergence of rough colonies', whose bacteria have lost the ability to synthesize mucopolysaccharide (and therefore have no capsules). Rough mutants could no longer be classified with sera and, moreover, lost their virulence: mice inoculated with them remained alive, unlike inoculated with smooth pneumococci.
The nature of Griffith's transforming principle remained unclear until the work of Avery, MacLeod, and McCarty. They repeated the in vitro transformation of pneumococci at the Rockfeller Institute for Medical Research, but replaced heat-dead cells with a purified fraction of smooth bacterial extract (unable to cause disease alone) and treated the material with different enzymes, each capable of destroying a specific type of macromolecule. Experience has shown that this fraction retained its transforming capacity when treated with protein or RNA degrading enzymes, but lost that ability when treated with DNA degrading enzymes. These results indicated that the chemical nature of the 'transforming principle' was DNA.
Thus, we can conclude that in addition to identifying genetic material, Avery, MacLeod and McCarty experiments with different strains of Streptococcus pneumoniae demonstrated that DNA can be absorbed by bacterial cells and be active.
The three type of tectonic plate boundaries are:
Convergent- two plates are moving towards each-other. Forms volcanoes, mountains and can cause earthquakes too.
Divergent - two plates are moving away from eachother. The space that is created between them is filled with lava from the mantle which cools to become part of the crust. These areas are hotspots.
Transform - two plates are moving against eachother (one down, one up etc.) They cause minor earthquakes.
Answer:
Over time, many species gradually adapted to a more oxygen-rich enviroment, allowing them to survive in shallow water and on land.
Answer:
The properties and structure of the bacteria is different so each of them would react differently. The antibiotic might help one of the bacteria while eliminating the other in the process.
(please tell me if im wrong)
(also, its nice seeing a genshin fan :)
Explanation:
11.099 births per 1000 people
