please help :) In an experimental investigation, the variable that the researcher changes or manipulates in order to see its effects is called the blank variable.

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

Cells destroy body cells infected by a virus or bacteria. killer t t memory t none of the above

Penelope studies how the structure and function of the nervous system is related to behavior. she is a psychologist