Different variations of a gene are called alleles.
Salmonella can spread to people in foods that have come into contact with infected animal feces. these exposures happen when food such as poultry, eggs, and beef are not cooked enough. Fruit and vegetables can also become contaminated from feces in the soil or water where they are grown.
Https://www3.epa.gov/climatechange/kids/impacts/effects/ecosystems.html
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D is the answer to the question
Explanation:
Compounds are those substances that are made up of elements that are combined in a fixed proportion or ratio. The individual property of element is lost once it forms a compound. The physical and chemical properties of both compound and an element is different.
Example of a compound is water and its elements are hydrogen and oxygen. Water is a colorless liquid that acts as a solvent and dissolves most of the solutes in it. While oxygen and hydrogen occurs as gases in their elemental state.