It is a sphere to be precise.
Because of the omnidirectional nature of the gravitational attraction, mass tends to form spheres in the macro scale of planets and similarly massive celestial bodies.
<span>Invasive species have particularly devastating effects on islands because island species have typically evolved with few competitors and predators.
And thus if an invasive species is introduced into these islands, it will have severe consequences given that islands don't normally have a lot of predators and competitors. This is why humans need to take care of what they are doing if they want to preserve their natural environment.
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An embryonic stem cell is the first cell in the embryo, this is what creates a human and helps more cells to form.
<span>it is Cardiac muscle tissue. Cardiac muscle tissue is an extremely specialized form of muscle tissue that has evolved to pump blood throughout the body. In fact, cardiac muscle is only found in the heart and makes up the bulk of the heart’s mass. The heart beats powerfully and continuously throughout an entire lifetime without any rest, so cardiac muscle has evolved to have incredibly high contractile strength and endurance. And because the heart maintains its own rhythm, cardiac muscle has developed the ability to quickly spread electrochemical signals so that all of the cells in the heart can contract together as a team....</span>
In complementary base pairing, the G pairs with C, and A pairs with T. Given that this be the rule, the complementary nucleotides for your sequence would be as follows: CGATTAACGTAGGCA.
With regards to proofreading, mutations in cell division occur once in around every 100,000 base pairs. If this happens, the enzyme that pairs the nucleotides to form DNA, called DNA polymerase, detects the error and moves back along the strand, it then cuts the incorrect nucleotide and replaces it with the correct one, fixing the error and continuing with the DNA synthesis.
This process corrects the majority of errors in DNA synthesis, but some errors can still be missed by the DNA polymerase, this is then rectified by a protein complex which binds to the incorrect pairing until anther complex, comes along and cuts that particular section of DNA out, which is then replaced by a new section of correct nucleotides synthesized by the polymerase enzyme, the two sections at either end that were cut is then sealed by ligase, an enzyme which essentially "glues" the DNA stands back together.
My apologies for the long answer, I hope I answered your question and that you understand it well enough.