In a series of experiments, griffith infected mice with nonvirulent r-strain bacteria and highly virulent s-strain bacteria. heat-killed s bacteria were nonvirulent. however, the nonvirulent heat-killed s bacteria and the nonvirulent r bacteria together produced a virulent mixture. what did this demonstrate?
a. the molecules present on the outside of bacteria determine whether it's virulent or nonvirulent.
b. a transforming principle in the s bacteria allowed the nonvirulent r strain to become virulent.
c. the translation of proteins, carbohydrates, lipids, and dna is important in determining bacterial virulence.
d. the s-strain bacteria had not been killed completely.

The correct answer is B.A transforming principle in the S bacteria allowed the nonvirulent R strain to become virulent.

Explanation:

In the transformation experiments, conducted by Fredrick Griffith in 1928, he observed that heat-killed S-strain bacteria injected into mice did not kill them. When he injected a mixture of heat-killed S and live R-bacteria, the mice died. He concluded that the R-strain bacteria had somehow been transformed by the heat-killed S-strain bacteria. This occurred perhaps due to absorption of some transforming principal or substance by rough type bacteria from heat killed smooth bacteria. It had enabled the R-strain to synthesize a smooth polysaccharide coat and become virulent. This must be due to the transfer of the genetic material. However, the biochemical nature of genetic material was defined not from his experiments.

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.