To treat Leukemia, doctors can take stem cells of a matching sibling and place them into the body of the sibling with the disease These cells will then enter the body and differentiate into bone marrow cells to help their body heal and build up the immune system. Why is it possible to take cells from a matching donor and place them in another person body?

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

To store strawberries in sugar syrup, lucy placed them in a jar and covered them with sugar but did not add any water. do you think syrup will be formed? justify. a. no. since water is not added, there cannot be any syrup formation. b. no. the higher concentration of sugar on the outside will cause the water from the sugar to diffuse in the strawberry cells causing them to swell without formation of any syrup. c. yes. the higher concentration of sugar on the outside will cause the water from the strawberry to diffuse out resulting in syrup formation. d. yes. the sugar will melt over time and form the syrup.

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above