This happens when two chromosomes pair up and exchange segments of DNA. Why is crossing over an important part of meiosis?

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

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

What should be the strand of complementary dna produced by the strand of dna shown below cgt ata