Substance abuse can spread STIs because when a user shares needles with an infected person, it can spread through the blood. Any high-risk behavior like this spreads STIs.
Do you have the sentence where the author uses the word?
Answer:
There are two paths of a drop of blood leaving the human heart. First, the deoxygenated blood leaves the heart and second, oxygenated blood leaves the heart,
Explanation:
Deoxygenated blood leaves the heart through an artery called pulmonary artery which take this blood to the lungs. After that, oxygenated blood carries from lungs to the heart through pulmonary vein. The oxygenated blood in the heart leaves the heart through aorta and distribute this blood in all parts of the body.
Answer:
I am writing this in response to a letter regarding evolution. Evolution is increasingly solid, not shaky. Darwin’s “theory” or explanation was a way of understanding what he had discovered (which did not include genes, chromosomes, DNA or nucleotide bases). Our explanations now include genetics and the commonality of mutation.
Proofs are solid, not in question by serious scientists. Direct observation is one, which we see in the fact that this year’s flu evolved a little too far from last year’s, so flu shots are less effective this year than we would like them to be.
Fossils tell the story well: whales with legs, dinosaurs with feathers and Tiktaalik. The latter was found in the Canadian north and is part fish, part amphibian, before there were ever any amphibians. Imperfection is a good proof: think of your useless appendix, the very bad design of your ankles, knees, and back (talk to a chiropractor about that). You have big toes because they used to be useful thumbs for your grasping feet.
Many other animals and even plants similarly have flaws that show their evolutionary past. Two large human chromosomes reflect the coming together of two chimpanzee chromosomes each.
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Thank you
Answer/Explanation:
The DNA in all living organisms is made up of 4 bases, adenine, thymine, guanine, cytosine. The RNA replaces thymine with uracil, making 5 types of nucleotide. The number of nucleotide pairs in a genome can range from half a million up to 100,000 million - meaning there are an exponential number of combinations of these 4 bases.
Imagine an organism exists that has only 2 nucleotides (<u><em>this is over 200,000x smaller than even the smallest bacterial genome</em></u>). If we allow any nucleotide at each of the 2 positions, then we have 4x4 (4²) or 16 possible combinations of sequences. For a nucleotide length of 4, the total number of possible combinations are 4⁴ or 256.
Since we are dealing with many millions of nucleotides, there are essentially infinite combinations of nucleotides, giving rise to the variation that produces over 20 million organisms on the planet.
