Answer:
2.765amu is the contribution of the X-19 isotope to the weighted average
Explanation:
The average molar mass is defined as the sum of the molar mass of each isotope times its abundance. For the unknown element X that has 2 isotopes the weighted average is defined as:
X = Mass X-19 * Abundance X-19 + MassX-21 * Abundance X-21
The contribution of the X-19 isotope is its mass (19.00 amu) times its abundance (14.55% = 0.1455). That is:
19.00amu * 0.1455 =
2.765amu is the contribution of the X-19 isotope to the weighted average
Adding acid and and catching the solution that drains through.
Answer:
This work was done in the European plum (Prunus domestica). The gene for PPV coat protein was separated from the PPV virus and inserted into the plum DNA, which was then regenerated and grown into complete plum trees. These trees now had the additional gene in their DNA and became resistant to PPV.