What is the proper ethical role of science in public policy? O to shape public opinion so that it agrees with science
to make government do the right thing
O to inform policy makers of the facts of an issue
O to refuse to testify on controversial issues

Transport of materials in Xylem :

Xylem tissues helps in the transport of water and minerals. Water is transported upwards from roots to aerial parts of plants. Transport in xylem requires physical forces such as transpiration pull.

Transport of materials in Phloem :

Phloem tissues helps in the transport of food. Food is transported in both upward and downward directions.Transport of food in phloem requires energy in the form of ATP.