He chart below shows the properties of nuclear fission and nuclear fusion. Type of nuclear reaction 1 2 3 4
Nuclear fission Produces lesser amount of energy than fusion. Involves combining of atoms to release energy Takes place at high temperature and pressure It can be controlled to generate electricity
Nuclear fusion Produces a large amount of energy in the sun Involves breaking up of atoms to produce energy Takes place at low temperature and pressure It cannot generally be controlled

Which of these columns in the table show correct information about nuclear fission and nuclear fusion?
Column 1 and Column 2
Column 2 and Column 3
Column 3 and Column 4
Column 1 and Column 4

When coal has reached it hardest, darkest form, it is called select one: 0 a. sub-bituminous b. lignite c. bituminous d. antrhacite next page

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.

What does the hardy-weinberg principle relate to? a. chances of survival of an organism b. frequency of alleles in a population c. natural selection in a species d. causes of evolution among organisms