The excretory system allows animals to remove metabolic waste their bodies. Many of these substances are potentially toxic. in Mammals nitrogenous toxins like urea are expelled through liquid urine while in reptiles and birds the nitrogenous compounds are expelled as a solid. This allows birds and reptiles to use less water in the processes of metabolism.
Scientists most often produce new genetic variations of organisms by causing mutations with radiation or chemicals and then selectively breeding in order to emphasize the desired traits in the new variations. The Dachshund is an example of this. By breeding two dogs with a similar mutation that caused student legs and elongated backs breeders were able to create a new variation not found in nature.
Answer:
o determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This is called the Rule of Superposition. ... With absolute age dating, you get a real age in actual years
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Magnet .................................
the center of the solar system is the sun
