In 1939, the use of DDT (a powerful synthetic chemical) as an insecticide was discovered. The United States adopted its widespread use, producing up to 100 million kilograms per year (200 million pounds per year). Twenty years later, severe side effects started to be reported as a result of DDT use. Which was an advantage of using DDT? insect and pest populations decreased birth defect rates increased cancer rates increased fertility rates decreased

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.

hi my name is ashlynn and im 15

these macromolecules could either be amino acids, proteins or nucleic acids. they are responsible for the chemical changes and reactions that affects largely the cell and its composition. take for instance the cytoplasm of the cell where these organelles are settled. these simple organelles are composed of macromolecules which ignites and catalyses different functions that enables cells, in macro-perspective in motion and metabolism. in intestines for example, metabolism happens and breaking down parts of a food to simpler compounds that are used and these nutrients delivered throughout the body and again broken down by into smaller components.