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.
Answer:
neurocysticercosis
Explanation:
Cysticercosis is the infection caused by the cystic form of the pig's tapeworm, Taenia solium, and neurocysticercosis is when the central nervous system (CNS) is affected. It is usually possible through direct ingestion of helminth eggs, but it can also occur in a usual infestation (teniasis). It is an endemic condition in several countries in South America, Africa and Asia, accounting for about 29% of the causes of secondary epilepsy in these locations. It can also cause headache, hydrocephalus, meningitis, and even central nervous system infarction.
Answer:
Any object that is spherical in shape would best represent a true scale model of the shape of the Earth.
for example: ping pong balls, billiard balls, marble and other smooth spherical objects. The shape of the Earth is called the oblate spheroid.
Answer:
C. that there may be more than one way to interpret data
Explanation:
When determining if an explanation is correct you must always remember that there may be more than one way to interpret data. Depending on the context that the explanation is being used in or who is reading it, the explanation may be interpreted in two completely different manners which may be far off from the original intended explanation. This can therefore completely nullify or maybe even expand the original determination.
