Answer:
DNA and proteins
Explanation:
By comparing these specific molecules in two different species, scientists can determine how closely related the species are.
Skin color<span> is due primarily to the presence of a pigment called melanin , which is controlled by at least 6 genes. Both light and dark complexioned people have melanin. However, two forms are produced--pheomelanin , which is red to yellow in</span>color<span>, and eumelanin , which is dark brown to black</span>
Multiple species aka animals, humans, plants and all the species interactions :)
Answer: c
Explanation: Plants and animals need nitrogen to make proteins but they cannot take it in from the air. Because nitrogen is unreactive as a gas, it has to be transformed into a new molecule. When bacteria in the soil takes nitrogen from the air, it becomes nitrates. Finally, it can move through the food chain in this form.
