<h2>DNA </h2>
Explanation:
1) Experiment done by Griffith:
- Griffith used two related strains of bacteria, known as R and S
- R bacteria were nonvirulent, meaning that they did not cause sickness when injected into a mouse whereas mice injected with live S bacteria developed pneumonia and died
- Griffith tried injecting mice with heat-killed S bacteria (that is, S bacteria that had been heated to high temperatures, causing the cells to die), the heat-killed S bacteria did not cause disease in mice
- When harmless R bacteria were combined with harmless heat-killed S bacteria and injected into a mouse, not only did the mouse developed disease and died, but when Griffith took a blood sample from the dead mouse, he found that it contained living S bacteria
- Griffith concluded that the R-strain bacteria must have taken up what he called a transforming principle from the heat-killed S bacteria, which allowed them to transform into smooth-coated bacteria and become virulent
2) Experiment done by Avery:
- Avery, McCarty and MacLeod set out to identify Griffith's transforming principle
- They began with large cultures of heat-killed S cells and, through a long series of biochemical steps progressively purified the transforming principle by washing away, separating out, or enzymatically destroying the other cellular components
- These results all pointed to DNA as the likely transforming principle but Avery was cautious in interpreting his results
- He realized that it was still possible that some contaminating substance present in small amounts, not DNA, was the actual transforming principle
3) Experiment done by Hershey and Chase:
- Hershey and Chase studied bacteriophage, or viruses that attack bacteria
- The phages they used were simple particles composed of protein and DNA, with the outer structures made of protein and the inner core consisting of DNA
- Hershey and Chase concluded that DNA, not protein, was injected into host cells and made up the genetic material of the phage
Neptune takes the longest to orbit the sun because its distance from the sun is really far away.
hope i helped :)
Answer:
When the carbon dioxide concentrations rise, the air temperature will rise as well due to the greenhouse gases heating up and multiplying.
Explanation:
Carbon dioxide causes about 20 percent of Earth's greenhouse effect; water vapour accounts for about 50 percent; and clouds account for 25 percent. ... Likewise, when carbon dioxide concentrations rise, air temperatures go up, and more water vapour evaporates into the atmosphere—which then amplifies greenhouse heating.
The correct answer is B. Two oppositely-charged ions
Explanation:
In chemistry, ionic bonds only occur between ions oppositely charged, this means one of the ions has to be positively charged and the other has to be negatively charged. This is because there is a natural attraction between particles with different charges and this leads to the formation of chemical bonds. Also, this bond implies the transfer of electrons between ions. In this context, this type of bond can only occur with oppositely-charged ions. Moreover, particles with the same charges either negative, positive, or neutral do not experience attraction and cannot form ionic bonds.
Atoms are not composed of <u>xenons.</u>
