Describe the sex and characteristics of the person labeled a

The person labeled A is a male who has the particular disease stated in the question.

 Person labeled as A is male, who is affected with disease.

Explanation: The diagram showing in image is pedigree chart. Pedigree chart is the diagrammatical representation of family information. In which round shape symbol is for female and square shape symbol is for male. In the chart if symbols are colored it shows that the person is affected with disease.

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs