What technique did scientists use to determine what diatoms occurred historically in the lake where Stephanodiscus yellowstonensis now occurs? My teacher is wanting the class to find the answer in this article: https://flexbooks. ck12.org/cbook/ck-12-middle-school- life-science-2.0/section/4.9/primar y/lesson/origin-of-species-ms-ls

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation:

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.