Natural selection<span> and selective breeding can both cause changes in animals and plants. The </span>difference between<span> the two is that </span>natural selection<span> happens naturally, but selective breeding only occurs when humans intervene. For this reason selective breeding is sometimes called </span>artificial selection<span>.</span>
Answer:
Carbon Cycle: the series of processes by which carbon compounds are interconverted in the environment, involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels.
Explanation:
D. He controlled variables by studying one or two traits at a time
Answer:
The correct answer is <em>c. animal wastes and fertilizers. </em>
Explanation:
Two major sources of nitrate pollution are farming and breeding activities. There are also certain industrial activities involved in nitrate pollution, but in general, these industries are related to agriculture.
The indiscriminate use of fertilizers for several years in intensive productions produce high nitrate concentration in soil and consequently elevate the risk of nitrate lixiviation.
Breeding animals produce nitrate pollution by their wastes, which accumulate and are not treated. These wastes include flesh, hair, feathers, skin, fat, liquids, excrements, among others. These wastes are an important source of nitrate.
In many cases, animal wastes are used by farmers as organic matter to improve their production. But excessive and incorrect use of it might produce severe damage in water sources.
