This was because one cannot view a single strain of DNA as it is too small for one to visually comprehend.
There is evidence that Emanuel Swedenborg<span> first proposed parts of the nebular hypothesis in 1734.</span>[3][4] Immanuel Kant<span>, familiar with Swedenborg's work, developed the theory further in 1755, publishing his own </span>Universal Natural History and Theory of the Heavens, wherein he argued that gaseous clouds (nebulae<span>) slowly rotate, gradually collapse and flatten due to </span>gravity<span>, eventually forming </span>stars<span> and </span>planets.<span>[2]</span>
Answer:
Animal Waste and Fertilizers
Explanation:
Animals, like humans, obtain nitrogen from consuming foods. The foods that the animals consume get digested and with time, the animals release the extra undigested foods and nutrients in forms of urine and feces. Like wise, fertilizers are typically made with animal waste.
As we can see in the pedigree, both of the parents do not possess the trait, but one of the four offspring (marked with red) is expressing the trait.
Since the trait is recessive, the only way that is possible that the parents who do not possess the trait to have the offspring with the trait is that the parents are heterozygous for the trait. Meaning that both of the parents have one dominant allele and one recessive allele.