Answer/Explanation:
First, initiator protein unwinds a short stretch of the DNA double helix. <u>The length of the DNA double helix about to be copied must be unwound. </u> In addition, the two strands must be separated, much like the two sides of a zipper, by breaking the weak hydrogen bonds that link the paired bases. Once the DNA strands have been unwound, they must be held apart to expose the bases so that new nucleotide partners can hydrogen-bond to them. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
The endosymbiotic theory hypothesizes that mitochondria and chloroplasts were formed when <u>prokaryotic </u>cells were engulfed by larger cells that were precursors to <u>eukaryotic </u>cells.
prokaryotic ; eukaryotic
When a single copy of a disease allele doesn't result in a disease but instead is good for the person or organism that carries it, we say that allele has a heterozygote advantage. In other words this occurs when heterozyhotes have increased fitness over both homozygotes. A good example is sickcle cell trait, which protects against malaria in heterozygotes, but causes a deadly disease in homozygotes.
Answer:
atoms determine the number of valence electrons determine the stability of the atom based on reading the topography of the atmosphere
