Shells are considered biotic because they come from living things. Biotic describes something living or use to be living such as plants and animals. So shells are considered biotic because they come from a living organism.
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Hope that helped:)
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Do you genuinely want help or ru trolling bc that’s actually common sense lol
Because the three-horned alien is heterozygous, we know that three must be dominant to four, because the gene for the three horns is "hiding" the gene for four horns. Therefore, the three-horned alien has the genotype Tt (T for three horns, and t for four horns). The four horned alien must be tt, because that is the only way that a recessive trait may be seen. If you solve the punnet square on a cross between Tt and tt, you end up with half three (heterozygous) and half four (homozygous recessive) it is a bit easier to explain with something a little "closer to home" if you want me to explain it again, just say so, I don't mind!
<span>The heart contains four chambers: upper left atria, upper right atria, lower left ventricle and the lower right ventricle. Oftentimes, the right atria and right ventricle are together referred to as the "right heart" and the left atria and left ventricle are referred to as the "left heart", however there are still four separate chambers.</span>
The relationship between annual earnings and education attainment is the higher the education level , the higher the income .